[Index]
Monthly Global Tropical Cyclone Summary August 2006
[Summaries and Track Data] [Prepared by Gary Padgett]
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Monthly Global Tropical Cyclone Summary August 2006 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
AUGUST, 2006
(For general comments about the nature of these summaries, as well as
information on how to download the tabular cyclone track files, see
the Author's Note at the end of this summary.)
NOTE FROM THE AUTHOR: Almost two years ago I began including links to
track graphics prepared by John Diebolt of Tucson, Arizona, and archived
on his tropical cyclone website. A few months back John experienced a
disk crash which resulted in a error. He had to request assistance from
the programmer who had written the map-generation software, but so far
has not been able to get the problem solved. As a convenience to users,
I've also recently been including links to the individual tabular tracks,
prepared by myself, which John had archived on his website. Now, due to
family issues, John has not had time to place the tracks for the August
cyclones on the website. I have checked the websites listed at the end
of the summaries and found that the entire August track file has been
archived on two of them. The links are:
http://australiasevereweather.com/cyclones/2007/trak0608.htm>
http://www.typhoon2000.ph/garyp_mgtcs/aug06tks.txt>
*************************************************************************
AUGUST HIGHLIGHTS
--> Atlantic rather quiet--tropical storm affects Haiti, Cuba, Florida
and U. S. Eastern Seaboard
--> Eastern North Pacific very active--one hurricane adversely affects
the Baja California Peninsula
--> Extremely long-lived Central and Western Pacific major hurricane/
super typhoon strikes both Johnston and Wake Islands
--> Western North Pacific very active--China experiences very rare
strike by a destructive super typhoon
--> Several weak depressions in Bay of Bengal
*************************************************************************
!!!!!!!!!!!!!! EXTRA FEATURE !!!!!!!!!!!!!!
ADDENDUM TO JULY SUMMARY
System South of Nova Scotia on 17 July
--------------------------------------
An interesting-looking system south of Nova Scotia on 17 July may
possibly have been a tropical or subtropical storm. The system was
small, had a tight LLCC, anticyclonic outflow, and Buoy 44137 reported
sustained gale-force winds and 5 to 6-metre significant wave heights.
I do not currently have any more information available on this system,
but Eric Blake of TPC/NHC has indicated that it will be reviewed for
possible inclusion as an unnamed storm. The main issues to be determined
are whether or not it was warm-core and if it was attached to a frontal
boundary.
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for August: 2 tropical storms
1 hurricane
Sources of Information
----------------------
Most of the information presented below was obtained from the
various tropical cyclone products issued by the Tropical Prediction
Center/National Hurricane Center (TPC/NHC) in Miami, Florida:
discussions, public advisories, forecast/advisories, tropical weather
outlooks, special tropical disturbance statements, etc. Some
additional information may have been gleaned from the monthly
summaries prepared by the hurricane specialists and available on
TPC/NHC's website. All references to sustained winds imply a
1-minute averaging period unless otherwise noted.
Atlantic Tropical Activity for August
-------------------------------------
Following are some statistics for the Atlantic basin during the month
of August:
August Average
Parameter 2006 1950 - 2005
--------------------------------------------------------
Named Storms (NS) 3 2.8
Hurricanes (H) 1 1.6
Intense Hurricanes (IH) 0 0.6
Named Storm Days (NSD) 12.75 12.1
Hurricane Days (HD) 0.50 5.7
Intense Hurricane Days (IHD) 0.00 1.3
As can be seen, the month of August, 2006, was well below average in
all but the NS and NSD categories. The overall net tropical cyclone
activity (utilizing all six parameters) was only 47% of the amount of
tropical cyclone activity normally seen in August. By way of contrast,
the Northeast Pacific basin was much above normal in August, 2006, with
the net activity for that basin almost 2.5 times the average. The month
was the quietest August in the Atlantic basin since 2002 when three NS
developed with none reaching hurricane intensity.
Activity began early in the month when Tropical Storm Chris blossomed
near the Leeward Islands. Even though Chris became well-organized and
approached hurricane intensity, unfavorable shear and dry air led to the
storm's dissipation as it moved into the southeastern Bahamas. During
the fourth week of the month a well-organized and vigorous tropical wave
exited the African coast and prompted the issuance of tropical storm
warnings for the Cape Verde Islands. The system, however, slipped on
south of the islands before being upgraded to Tropical Storm Debby.
After its rather distinguished beginning, however, Debby moved west-
northwestward through a less-than-optimum environment and never
intensified beyond 45 kts, eventually dissipating between Bermuda and
the Azores.
Late in the month a tropical wave ahead of Debby began to strengthen
as it approached the Lesser Antilles and became Tropical Storm Ernesto
in the eastern Caribbean Sea. Ernesto briefly became the season's first
hurricane while situated near southwestern Haiti, but interaction with
the mountainous terrain led to the storm's weakening. Ernesto moved
northwestward across eastern Cuba, then turned northward and moved over
portions of the Florida Peninsula. The cyclone subsequently moved back
over the Atlantic and accelerated north-northeastward and intensified,
reaching the North Carolina coast near Cape Fear just shy of hurricane
intensity. Ernesto's remnants moved northward across Virginia, Maryland,
Pennsylvania, New York and finally into Ontario, causing fairly
significant rainfall totals in many areas. Reports follow on all three
of the named storms.
One other weather system in August warrants mentioning. By mid-day on
13 August a non-tropical low pressure system located about 280 nm east
of the northeastern Florida coast was producing a small area of showers
and thunderstorms. The next day a new circulation center seemed to be
developing just north of the Bahamas while the old center to the north-
east was becoming less organized. By mid-day on the 15th a surface
LOW had become better organized about 260 nm southeast of the North and
South Carolina coasts. While convection was minimal at the time,
environmental conditions were forecast to become more favorable for
development. Convection increased on the morning of 16 August, the
center then being located about 110 nm south of the Carolina coastline.
An Air Force reconnaissance plane flew a mission into the system during
the afternoon and found peak surface winds of only 20 kts in a few
isolated thunderstorms. While the potential existed for a tropical
depression to form, upper-level winds were forecast to become
increasingly unfavorable over the next few days. On the 17th the weak
LOW began to drift westward and later southwestward. By the early
morning of 18 August the LOW was centered about 85 nm east-northeast of
Jacksonville, Florida, and remained poorly organized. Early on the
19th, while located only about 50 nm east of Jacksonville, the LOW
appeared to be a little better organized, but conditions were still not
conducive for strengthening. The LOW continued to drift westward toward
the northeastern Florida coast through the 19th as it weakened. The
final mention by TPC/NHC was in the afternoon Tropical Weather Outlook
issued at 5:30 PM EDT on 19 August.
TROPICAL STORM CHRIS
(TC-03)
1 - 5 August
----------------------------------------
Tropical Storm Chris was a short-lived, though briefly well-organized,
tropical cyclone which flared up near the Leeward Islands very early in
August. The origins of Chris lay with a westward-moving tropical wave
which left the African coast in late July. It was first mentioned in a
Tropical Weather Outlook issued by TPC/NHC on the afternoon of 27 July
when it was located about 480 nm southwest of the Cape Verde Islands.
Vertical shear inhibited development for several days, but as the system
approached the Lesser Antilles on 31 July conditions became somewhat more
favorable for tropical cyclogenesis. The first advisory on Tropical
Depression 03 was issued at 0300 UTC on 1 August, placing the center
about 140 nm east-southeast of Antigua. Reports from a French buoy
during the afternoon indicated that a weak circulation was associated
with the tropical wave and the system was maintaining enough deep
convection to be classified as a tropical depression. However, due to
some westerly shear resulting from strong easterlies in the lower
troposphere, the presence of a large upper-level LOW just east of the
Bahamas, and a very dry air mass, the depression was not forecast to
reach tropical storm intensity but rather to dissipate within three
days.
During the night the depression slowed its forward speed and deep
convection increased in both depth and organization around the LLCC.
Also, both TAFB and SAB estimated the intensity at 35 kts, and two
consecutive AMSU intensity estimates were at 35-36 kts. Therefore, on
the second advisory TD-03 was upgraded to Tropical Storm Chris at 0900
UTC. During the afternoon the first aerial reconnaissance was flown
into Chris, and the Hurricane Hunters found a very small core of strong
winds with a CP of 1007 mb--rather low considering the high environmental
pressures. A peak FLW of 53 kts was found just southeast of the center,
and the intensity was bumped up to 40 kts in the 01/2100 UTC advisory.
However, shortly after the issuance of that advisory, the Hurricane
Hunters found a 64-kt FLW along with a 1003-mb pressure, so a special
advisory was issued upping the winds to 50 kts. Since some of the models
were forecasting a decrease in the vertical shear, Chris was forecast
to increase to hurricane intensity in three days.
Chris strengthened slightly and reached its peak intensity of 55 kts
around 1200 UTC on 2 August when centered approximately 55 nm north of
the island of St. Martin and moving west-northwestward at about 9 kts.
The latest FLW measured by a reconnaissance aircraft was 67 kts and both
TAFB and SAB had assigned Dvorak ratings of T3.5. By late on the 2nd
Chris had turned to more of a westerly heading and the MSW had dropped
slightly to 50 kts. Early on the 3rd it was becoming apparent that
Chris was weakening in a hurry. The combination of low and mid-level
dry air and shear associated with an upper-level cyclone which had
dropped southward into Chris was taking its toll on the tropical storm.
By 03/1200 UTC Chris was only a minimal tropical storm 250 nm east-
southeast of Grand Turk Island, and was devoid of any deep convection
within a 75-nm radius of the center. The forecast called for Chris
to weaken into a tropical depression within 12 hours, but the cyclone
stubbornly hung on to its tropical storm status for another 24 hours.
Finally, at 1200 UTC on 4 August, Chris was downgraded to a depression
located about 15 nm south of Grand Turk and moving toward the west at
11 kts. The final advisory, issued at 05/0900 UTC, placed only a weak
20-kt center about 130 nm east of Camaguey, Cuba. The system was
becoming a broad low-pressure area devoid of thunderstorm activity.
It was felt that there was a slight chance that the system might undergo
some modest re-intensification later in the Gulf of Mexico, but this
failed to materialize.
Damage caused by Tropical Storm Chris was generally minor and mainly
consisted of local flooding. Several inches of rain fell over many of
the islands in the Lesser and Greater Antilles, leading to some homes
being flooded and causing some crop losses. Fortunately, there were no
casualties associated with the storm.
The online Wikipedia report on Chris, from which some of the above
information was taken, is available at the following URL:
http://en.wikipedia.org/wiki/Tropical_Storm_Chris_%282006%29>
(Report written by Gary Padgett)
TROPICAL STORM DEBBY
(TC-04)
21 - 27 August
----------------------------------------
The precursor of Tropical Storm Debby was a very well-organized and
vigorous tropical wave which moved off the African coast on 20 August.
Shower and thunderstorm activity decreased some on the 21st, but the
low-pressure area associated with the wave remained well-organized and
advisories were initiated on Tropical Depression 04 at 2100 UTC that
afternoon. The depression was centered about 220 nm southeast of the
southernmost Cape Verde Islands and moving west-northwestward at 10 kts.
Because the projected path of the system took it through or very near
the Cape Verdes and intensification was forecast, a tropical storm
warning was issued for the islands. However, the system passed over
100 nm south of the Cape Verdes on the 22nd so the effects there were
limited to some rainfall with no damage reported.
As the cyclone passed to the south of the Cape Verdes, deep central
convection continued to increase and Tropical Storm Debby was christened
at 0300 UTC on 23 August. The upgrade was based on satellite intensity
estimates of 35 kts from SAB, TAFB and AFWA, and also several AMSU
estimates of tropical storm intensity. In addition, a 22/2027 UTC
QuikScat overpass showed several 30-35 kt uncontaminated wind vectors
near the circulation center. Debby at this time was centered about
260 nm west of the southernmost Cape Verde Islands, scooting off to
the west-northwest at 16 kts. Debby rather quickly reached an initial
peak intensity of 45 kts at 23/1200 UTC, but shortly thereafter
encountered some dry air which led to the convection diminishing and the
storm weakening some. By the 24th the convection had redeveloped near
the center and banding features had redeveloped as well, so the cyclone
again reached an intensity of 45 kts at 24/1200 UTC as it continued
west-northwestward across the eastern Atlantic Ocean.
Early on the 25th the storm began to weaken due to increasing
southerly shear, and by 25/1200 UTC had become a minimal tropical storm.
Further weakening ensued and Debby was downgraded to a tropical
depression at 1500 UTC on 26 August. During its dissipating stages
the system turned more or less due northward. TPC/NHC issued its
final advisory on Tropical Depression Debby at 2100 UTC on the 27th,
placing the center approximately 700 nm west-southwest of the Azores.
No damage or casualties are known to have resulted from Tropical
Storm Debby.
The online Wikipedia report on Debby may be accessed at the following
URL:
http://en.wikipedia.org/wiki/Tropical_Storm_Debby_%282006%29>
(Report written by Gary Padgett)
HURRICANE ERNESTO
(TC-05)
24 August - 3 September
-------------------------------------------
A. Storm Origins
----------------
A tropical wave left the African coast ahead of the one which
produced Tropical Storm Debby but remained insignificant until the
22nd when it was first mentioned in a Tropical Weather Outlook issued
by TPC/NHC. The system gradually began to show signs of increased
organization as it approached the Lesser Antilles. A reconnaissance
aircraft during the afternoon of the 24th was able to close off a
surface circulation and advisories were begun on Tropical Depression 05
at 2100 UTC that day. The center of the new depression was located
about 135 nm southwest of the island of Martinique and moving quickly
westward at 19 kts. Earlier in the afternoon Barbados had reported
sustained winds of 33 kts, but the direction of those winds suggested
a convective outflow or downburst not representative of the cyclone's
circulation. TD-05 was initially forecast to increase to tropical
storm intensity soon, but this was delayed for about 24 hours due to
the storm's passage through an environment of moderate shear.
B. Synoptic History
-------------------
Tropical Storm Ernesto was christened at 2100 UTC on 25 August when
located about 260 nm south-southwest of San Juan, Puerto Rico. An
Air Force reconnaissance aircraft had found a peak FLW of 48 kts at
300 meters about 40 nm northeast of the center along with a CP of
1004 mb. Vertical shear continued to hamper Ernesto's intensification
as it plodded west-northwestward across the central Caribbean Sea,
gradually slowing its forward speed. The shear began to abate some
on the 27th and the cyclone began to strengthen, reaching hurricane
intensity at 1200 UTC when located about 100 nm southwest of Port-au-
Prince, Haiti, or about 185 nm south-southeast of Guantanamo Bay,
Cuba. The MSW had been bumped up to 60 kts in the 27/0900 UTC advisory
based on the formation of an eye and maximum FLWs of 78 kts at 850 mb
in the northeast quadrant. The forecast associated with this particular
advisory called for a Category 3 hurricane in the eastern Gulf of Mexico
in 96 hours, but it was the previous advisory's forecast (27/0300 UTC)
which really had had a sobering effect among residents and emergency
managers in that it called for a Category 3 hurricane to be advancing
toward the central Gulf Coast in 5 days--areas which had been devastated
by Katrina exactly one year earlier. Fortunately, this scenario failed
to materialize.
Even as Ernesto was upgraded to a hurricane, its appearance in
satellite imagery was becoming ragged. The upper-level LOW which had
been responsible for the vertical shear plaguing Ernesto had retreated
westward and shear had significantly diminished, so it appears that
involvement with the rugged terrain of southwestern Haiti was the main
factor which had resulted in Ernesto's weakening. The cyclone moved
northwestward, crossing the extreme southwestern portion of Haiti, then
continuing northwestward toward the southern Cuban coastline. The
cyclone had weakened to 45 kts during its encounter with Haiti and did
not intensify while back over water in the north-central Caribbean.
Ernesto moved onshore in Cuba around 1200 UTC on 28 August about 30 nm
west of Guantanamo Bay, moving northwestward near 9 kts. The center of
the storm spent almost 24 hours over eastern Cuba, emerging into the
Florida Straits by 29/1200 UTC. The tenuous system managed to hang onto
minimal tropical storm intensity while over the island and had
re-intensified to 40 kts by 1200 UTC.
With Ernesto over the very warm Florida Straits, intensification
seemed very likely and for a time the storm did become somewhat more
organized-looking in radar and satellite imagery, but by the afternoon
of the 29th its presentation had become a bit ragged-looking. It was
suggested that one negative factor might have been some modest easterly
shear which showed up in water vapor images. Ernesto's track became
increasingly northerly as it neared the southern tip of the Florida
Peninsula. The storm's center made landfall about 13 nm east of Flamingo
or about 45 nm south-southwest of Miami around 0600 UTC on 30 August with
a MSW of 40 kts. The storm began to weaken after moving inland and was
downgraded to a tropical depression at 30/1500 UTC while passing about
85 km (55 miles) west-southwest of West Palm Beach. By 0300 UTC on the
31st Ernesto was emerging into the Atlantic near Cape Canaveral, and at
0600 UTC was re-upgraded to tropical storm status just off the Florida
East Coast about 205 nm south-southwest of Charleston, South Carolina.
The cyclone's forward motion had picked up a bit to 13 kts, and a turn
toward the north-northeast at a faster speed was forecast.
By 1500 UTC on 31 August Ernesto's intensity had increased to 50 kts
and the cyclone was moving north-northeastward at 15 kts. Atmospheric
conditions were favorable for strengthening, and as Ernesto passed over
the warm Gulf Stream waters, its MSW increased to 60 kts before the
center made landfall just west of Cape Fear, North Carolina, around
0600 UTC on 1 September. As a precaution, hurricane watches were issued
for portions of the Carolina coastlines. Following landfall Ernesto
began to quickly weaken and was downgraded to a tropical depression at
1500 UTC on 1 September while located about 130 km (80 miles) west-
southwest of Norfolk, Virginia, and responsibility for issuing advisories
was shifted to the Hydrometeorological Prediction Center. The weakening
tropical cyclone moved northward across North Carolina into Virginia and
had evolved into an extratropical gale by 0300 UTC on 2 September near
West Point, Virginia. The system continued moving northward, still
producing gale-force winds over the Atlantic through 02/2100 UTC. The
final HPC advisory, issued at 03/0300 UTC, placed the center about 80 km
(50 miles) east-southeast of State College, Pennsylvania. The remnants
continued northward, moving into New York later on the 3rd and finally
dissipating in southeast Ontario on the 4th as it was absorbed into a
developing occluded cyclone in Maine.
C. Storm Impact
---------------
Information in this section is largely taken from the excellent
online Wikipedia report on Hurricane Ernesto. More detailed information
may be found by consulting this report, available at the following URL:
http://en.wikipedia.org/wiki/Hurricane_Ernesto_%282006%29>
Hurricane Ernesto was responsible for bringing heavy rains to all the
Greater Antilles except Jamaica. In Puerto Rico 119.1 mm of rain fell
in two days at the Sabana Grande ALERT station. In the Dominican
Republic heavy rainfall caused river flooding and landslides, leading
to damage to some houses and also downing trees. Over 1600 people were
evacuated near Santo Domingo.
Some portions of Haiti experienced over 300 mm of rainfall in
association with Ernesto, causing flooding which destroyed homes and
ultimately was responsible for 5 fatalities in the nation. In Cuba
Guantanamo reported over 75 mm of rainfall in four hours. In that nation
more than 700,000 persons were evacuated but no deaths, injuries nor
major damage were reported.
Ernesto brought heavy rains to several areas of the U. S. In Florida
the highest storm total measured was 221 mm at South Golden Gate Estates
in Collier. The heavy rainfall was responsible for auto accidents which
left at least two persons dead. Several thousand residents experienced
power outages for a short time.
In South Carolina the highest rainfall total related to Ernesto was
146 mm at Blythewood on Cedar Creek. In North Carolina prodigious
rains fell in many areas as moisture from Ernesto interacted with a
frontal boundary, but the maximum total of 371 mm recorded near
Wrightsville Beach was associated directly with the tropical cyclone
and most of this fell within a 24-hour period. One traffic fatality
in North Carolina was blamed on Ernesto, and crop damage in the state
was estimated to total $76 million.
Wakefield, Virginia, recorded 258 mm of rainfall during Ernesto's
passage with total damage in the state estimated at over $104 million.
Two people were killed in Gloucester County when high winds caused a
large tree to fall on a modular home. More than 600,000 people from
North Carolina to Connecticut experienced power outages resulting from
Ernesto. Tragically, one woman died from carbon monoxide poisoning
from a portable electrical generator being used during the power
outage. The combination of a large high pressure system and the
weakening tropical cyclone produced a large area of gale-force winds
which affected much of the Mid-Atlantic and Northeastern coastal areas
of the U. S. These gales caused high tides which swamped St. George
Island in St. Mary's County, Maryland. Rains generally between 50
and 100 mm fell across Pennsylvania and New York during the last stages
of Ernesto.
More information on Ernesto�s rainfall may be found at the following
URL:
http://www.hpc.ncep.noaa.gov/tropical/rain/ernesto2006.html>
(Report written by Gary Padgett)
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for August: 2 tropical storms
2 hurricanes
3 major hurricanes **
** - one of these formed in Central North Pacific and became a Western
Pacific super typhoon
Sources of Information
----------------------
Most of the information presented below was obtained from the
various tropical cyclone products issued by the Tropical Prediction
Center/National Hurricane Center (TPC/NHC) in Miami, Florida (or the
Central Pacific Hurricane Center (CPHC) in Honolulu, Hawaii, for
locations west of longitude 140W): discussions, public advisories,
forecast/advisories, tropical weather outlooks, special tropical
disturbance statements, etc. Some additional information may have
been gleaned from the monthly summaries prepared by the hurricane
specialists and available on TPC/NHC's website. All references to
sustained winds imply a 1-minute averaging period unless otherwise
noted.
For the portion of Hurricane/Typhoon Ioke's track lying west of
longitude 180 the following applies:
Most of the information presented below is based upon tropical
cyclone warnings and significant tropical weather outlooks issued
by the Joint Typhoon Warning Center of the U. S. Air Force and
Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion
tropical cyclone tracks file, I normally annotate track coordinates
from some of the various Asian warning centers when their center
positions differ from JTWC's by usually 40-50 nm or more. All
references to sustained winds imply a 1-minute averaging period
unless otherwise noted.
Northeast Pacific Tropical Activity for August
----------------------------------------------
Following are some statistics for the Northeast Pacific basin during
the month of August:
August Average
Parameter 2006 1971 - 2005
--------------------------------------------------------
Named Storms (NS) 7 4.0
Hurricanes (H) 5 2.3
Intense Hurricanes (IH) 3 1.1
Named Storm Days (NSD) 27.00 19.9
Hurricane Days (HD) 16.00 8.0
Intense Hurricane Days (IHD) 7.25 1.7
As can be seen, the month of August, 2006, was far above average in
all categories. The overall net tropical cyclone activity (utilizing
all six parameters) was a whopping 238% of the amount of tropical cyclone
activity normally seen in August. By way of contrast, the Atlantic
basin was well below normal in August, 2006, with the net activity for
that basin only about half the average level. The month was the most
active August in the Northeast Pacific basin since 2002 when five NS
developed with three becoming intense hurricanes. Similarly to Hurricane
Ioke of 2006, Hurricane Ele of 2002 formed in the Central North Pacific,
reached major hurricane intensity and entered the Northwest Pacific
basin as an intense typhoon. Unlike Ioke, however, Ele did not reach
Category 5 intensity.
Tropical Storms Fabio and Gilma were both short-lived weak tropical
cyclones at the beginning of the month. Hurricane Hector formed around
mid-month well southwest of Mexico and moved almost to 140W before
dissipating, becoming a Category 2 hurricane along the way. Hurricane
Ileana formed late in the 3rd week of August at the same time that Ioke
was forming in the Central Pacific. Ileana became a Category 3 hurricane
but remained well off the Mexican coast. Hurricane John formed near the
end of the month just off the coast and became a Category 4 hurricane,
later weakening to Category 2 status just before striking the south-
eastern portion of the Baja California Peninsula. Hurricane Kristy
formed farther west while John was operating near the coast of Mexico
and went through several intensity fluctuations while gradually
weakening. Reports follow on all seven of the named cyclones.
The online Wikipedia reports for the Eastern Pacific cyclones may
be accessed at the following URL:
http://en.wikipedia.org/wiki/2006_Pacific_hurricane_season>
More expanded reports are available for Hurricane John and Hurricane/
Typhoon Ioke. The links are included in the individual reports for
those cyclones.
TROPICAL STORM FABIO
(TC-07E)
31 July - 3 August
----------------------------------------
Tropical Storm Fabio formed from a tropical wave which had emerged
from the coast of Africa on 15 July. The wave marched steadily across
the tropical Atlantic and Caribbean and crossed Central America into the
Eastern Pacific on 23 July. Convection began to increase along the
wave during the following days and a weak low pressure area had formed
by 28 July about 500 nm southwest of Manzanillo, Mexico. Over the next
three days the LOW moved northwestward, slowly becoming better organized.
By 31 July the system had acquired enough deep convection to be
designated as a tropical depression, and advisories were initiated on
Tropical Depression 07E at 2100 UTC. The center of TD-07E was then
located approximately 850 nm southwest of Cabo San Lucas on the southern
tip of the Baja California Peninsula. Six hours later the depression was
upgraded to Tropical Storm Fabio based on a consensus of satellite
intensity estimates of 35 kts or higher.
Throughout its life Fabio moved westward under the influence of a
mid-tropospheric ridge to the north and reached its estimated peak
intensity of 45 kts around 1200 UTC on 1 August while located about
1000 nm west-southwest of Cabo San Lucas. Fabio retained its peak
intensity for about 24 hours, then weakening set in due to the influence
of increasing vertical shear and a more stable air mass. The tropical
storm was downgraded to a depression at 03/0300 UTC when centered about
1400 nm west-southwest of the Cabo, and the final TPC/NHC advisory
at 03/2100 UTC placed the weakening depression about 975 nm east-
southeast of Hilo, Hawaii. The residual remnant LOW continued westward
and had degenerated into an open wave by 6 August.
No damage or casualties were attributed to Tropical Storm Fabio.
(Report written by Gary Padgett)
TROPICAL STORM GILMA
(TC-08E)
1 - 3 August
----------------------------------------
The precursor of Tropical Storm Gilma was a tropical wave which had
exited the coast of Africa on 17 July and had entered the Eastern Pacific
on the 25th. Convection began to increase on the 29th and by 01/0000 UTC
the system had acquired enough deep convection and sufficient
organization to be classified as a tropical depression. The first
advisory on Tropical Depression 08E was issued at 0300 UTC on 1 August
with the center about 400 nm south of Manzanillo, Mexico. In spite of
moderate easterly shear, the depression strengthened into a minimal
tropical storm later that day about 335 nm south-southwest of Manzanillo.
Gilma embarked on a generally west-northwesterly track roughly
parallel to the Mexican coastline. The persistent easterly shear,
however, hampered intensification and Gilma never intensified beyond
minimal tropical storm intensity of 35 kts, and was classified as a
tropical storm for only 18 hours. By early on 2 August the LLCC had
become completely exposed and Gilma was downgraded to depression status
at 02/0900 UTC. The depression continued moving slowly to the west-
northwest and slowly weakened. The final TPC/NHC advisory on Gilma,
issued at 2100 UTC on 3 August, placed only a weak 20-kt center about
425 nm south of Cabo San Lucas. The remnant LOW continued in the same
general direction and dissipated on the 5th about 325 nm south-southwest
of the Cabo.
No damage or casualties were attributed to Tropical Storm Gilma.
(Report written by Gary Padgett)
HURRICANE HECTOR
(TC-09E)
15 - 23 August
------------------------------------
Like its two predecessors, Hurricane Hector developed from a tropical
wave which had its origins in Africa. Hector's parent wave emerged from
the African coast on 31 July and reached the Eastern Pacific on the 10th
of August. Shower activity gradually increased as the system passed to
the south of the Gulf of Tehuantepec, and a broad low pressure area
developed about 425 nm south of Acapulco on 13 August. Convection
gradually became better organized and advisories were begun on Tropical
Depression 09E at 2100 UTC on 15 August with the system centered about
650 nm south-southwest of Cabo San Lucas. Within 12 hours Tropical Storm
Hector was christened and continued to intensify steadily, being upgraded
to a 75-kt hurricane at 1500 UTC on 17 August while located approximately
800 nm southwest of Cabo San Lucas. The upgrade was based on Dvorak
intensity estimates of 77 kts and 65 kts from TAFB and SAB, respectively.
Also, current AODT intensity estimates suggested that Hector was slightly
stronger than 70 kts.
Hurricane Hector continued moving west-northwestward along the south-
western periphery of a deep layer ridge extending over the Eastern
Pacific from the southwestern United States. The cyclone reached its
peak estimated intensity of 90 kts at 0900 UTC on the 18th while centered
about 900 nm west-southwest of the southern tip of the Baja California
Peninsula. The MSW was subsequently lowered slightly to 85 kts, but
was upped to 90 kts once more at 19/0900 UTC. By the 20th Hector was
entering a region of cooler SSTs and began to slowly weaken. The
cyclone was downgraded to a 60-kt tropical storm at 20/1500 UTC while
located approximately 1300 nm west-southwest of Cabo San Lucas, and
18 hours later had become a minimal tropical storm. On the 22nd Hector
turned to more of a westerly track and lost most of its deep convection,
weakening to a depression around 23/0000 UTC. The final TPC/NHC
advisory on Hector was issued at 23/0300 UTC and placed the weakening
cyclone roughly 1000 nm east-northeast of Hilo, Hawaii. The residual
LOW continued drifting westward and dissipated on the 24th.
No damage or casualties have been attributed to Hurricane Hector.
(Report written by Gary Padgett)
HURRICANE/SUPER TYPHOON IOKE
(TC-01C / TY 0612)
20 August - 7 September
------------------------------------------------
A. Introduction
---------------
Long-lived Hurricane/Typhoon Ioke was truly one of the most remarkable
tropical cyclones in many years. Forming in the Central North Pacific
to the south of Hawaii--a region where tropical cyclones are rather rare
events--the storm reached an intensity in that region only very rarely
seen, and maintained itself as a very intense tropical cyclone for well
over a week as it trekked from deep in the tropical Central Pacific to
recurvature a few hundred miles east of Japan. Along the way it
managed to make very close approaches to Johnston and Wake Islands--two
isolated outposts in the vast reaches of the Central and Western Pacific.
Following are a few statistics regarding Ioke's intensity:
(1) Consecutive days as a Category 3 or higher hurricane: 10.25
(2) Total days as a Category 3 or higher hurricane: 11.25
(3) Consecutive days as a Category 4 or higher hurricane: 8.50
(4) Total days as a Category 4 or higher hurricane: 9.00
(5) Consecutive days as a super hurricane/typhoon: 7.25
(6) Consecutive days as a super typhoon west of Dateline: 5.00
(7) Total days as a Category 5 hurricane/typhoon: 3.00
Ioke set several new records for intense tropical cyclone longevity.
The great cyclone was at Category 4 intensity for 9.00 days, besting
the previous record of 8.25 days set by Atlantic Hurricane Ivan in
2004. Also, Ioke was a Category 4 cyclone for 34 consecutive 6-hourly
synoptic periods, exceeding Ivan's record of 32 consecutive reporting
periods as a Category 4 hurricane. The previous Pacific record-holder
for Category 4 longevity was Typhoon Paka of 1997--a Category 4 or
higher storm for 6.75 days and consecutively for 6.25 days.
With regard to super typhoon intensity (MSW >= 130 kts), Ioke's reign
of 7.25 days greatly exceeds the 5.00 days of Super Typhoon Fengshen
in 2002 and 4.75 days set by Super Typhoon Joan in 1997--the previous
record holders. However, part of Ioke's life at 130 kts or higher was
east of the Dateline. West of the Dateline, Ioke was a super typhoon
for twenty 6-hourly synoptic periods--equaling Fengshen.
One final record--the estimated minimum CP of 920 mb for Ioke while
still east of the Dateline is likely to be the lowest CP on record for
a Central Pacific cyclone. An operational pressure of 910 mb was
assigned for 1994's Hurricane John, but according to Andy Nash of the
CPHC, the lowest CP for that hurricane in the new, revised Central
North Pacific Best Tracks file, due to be released in the near future,
will be 929 mb--the lowest reported by reconnaissance aircraft flying
into Hurricane John.
B. Synoptic History
-------------------
(1) Storm Origins
-----------------
The disturbance from which Ioke developed can be traced back to at
least 16 August. A Tropical Weather Outlook issued by CPHC at 2000 UTC
noted that an area of disturbed weather was located about 800 nm south-
east of Hilo and moving toward the west at around 13 kts. A recent Quik-
Scat pass had not indicated any evidence of a LLCC--only an east/west-
oriented trough. The disturbance continued westward and by the morning
of the 19th was located about 600 nm south-southwest of Hilo and had
shown some signs of increasing organization. By late afternoon (local
time) the system's organization had increased to the point that
advisories were initiated on Tropical Depression 01C at 20/0300 UTC.
The depression was then centered about 675 nm south of Honolulu and was
moving westward at 10 kts.
Only six hours later TD-01C had been upgraded to Tropical Storm Ioke,
the first named storm to develop in the Central North Pacific since
Hurricane Huko in October, 2002. The years 2003, 2004 and 2005 had all
produced a tropical depression numbered 01C, but in all cases the system
had only lasted for a day or so, being unable to escape the ITCZ and
eventually being overwhelmed by ITCZ convection. The upgrade to
tropical storm status was based upon Dvorak ratings of T2.5 from CPHC,
JTWC and AFWA. Also, a QuikScat pass had shown some 35-kt vectors with
even a few up to 40 kts. Incidentally, the name Ioke is a
transliteration of the name Joyce into the rather limited Hawaiian
alphabet and phonetic system.
(2) Birth to Johnston Island
----------------------------
The initial forecast upgrading Ioke to tropical storm status called
for the cyclone to attain hurricane intensity in 24 hours, and that is
what happened. During the afternoon of the 20th the system began to
intensify very rapidly with an eye appearing, so Ioke was upgraded to
a hurricane at 0300 UTC on 21 August while located about 685 nm south-
southwest of Honolulu. The cyclone at the time was moving toward the
west-northwest at around 13 kts. Ioke's intensification did not stop
after it became a hurricane. Only eighteen hours after being upgraded
the cyclone had intensified into a 100-kt Category 3 hurricane on the
Saffir/Simpson scale. Dvorak estimates were ranging from 90 to 102 kts
and the most recent AODT estimate was 110 kts. Major Hurricane Ioke was
by this time moving northwestward along the southwestern periphery of a
weak subtropical ridge and southeast of a deepening trough in the middle
and upper levels. The storm was becoming a threat to small Johnston
Island and a hurricane warning was issued at 21/2100 UTC for the atoll,
even though there are no longer any permanent residents.
Ioke continued to intensify and at 22/0300 UTC was upgraded to a
Category 4 hurricane with the MSW estimated at 115 kts, based on Dvorak
ratings of T5.5 and T6.0. The cyclone at this time was located about
200 nm southeast of Johnston Island and moving toward the island at
11 kts. By 22/1500 UTC Ioke was showing the first signs of weakening by
losing its warm center, the result of some westerly shearing at high
levels. The MSW was lowered to 90 kts at 1800 UTC with the hurricane's
center then located about 40 nm south-southeast of Johnston Island. By
2100 UTC the eye had become ill-defined and a water vapor loop showed
that the moisture field on the west side of the hurricane had eroded
some. Visible and infrared imagery showed a remnant northern eyewall
still likely intact about 10 miles south of Johnston. By 23/0000 UTC
the center of Ioke had slipped by to the south of the island and was
located about 25 nm to the south-southwest. Six hours later the storm
was about 35 nm to the west of the island, still moving northwestward
at 8 kts and maintaining an intensity of 90 kts. (Impacts to Johnston
Island will be discussed in Section D below.)
(3) Johnston Island to Dateline
-------------------------------
Hurricane Ioke maintained its 90-kt intensity through the remainder
of 23 August as it plodded slowly northwestward away from Johnston Atoll.
Two things happened on the 24th: the storm began to move on a west-
northwesterly track, and it began to intensify once again. By 24/0600
UTC Ioke had reached Category 3 status once more with a MSW of 100 kts,
and 12 hours later the winds were upped to 125 kts, making Ioke a
Category 4 hurricane once more. Visible pictures showed a symmetric
hurricane with a 20-nm eye and with deep convection wrapping completely
around the eye. Satellite intensity estimates were 127 kts from CPHC,
AFWA, JTWC and SAB. Hurricane Ioke was forecast to maintain intensity
for 36 hours, followed by slow weakening. One model, however, called
for the storm to reach Category 5 status after 48 hours. This model
had it right, only it was a little slow. Only 12 hours after being
re-upgraded to Category 4 status, Ioke was a Category 5 hurricane with
peak winds estimated at 140 kts, based on Dvorak ratings T6.5 and T7.0.
The hurricane at this time was centered about 315 nm west-northwest of
Johnston Island, far removed from any other islands.
As an anticyclone aloft began to build north of the hurricane, Ioke's
track became westerly. The 25/1500 UTC discussion from CPHC noted that
several hours earlier the well-developed and very warm eye had cooled
and the very cold surrounding cloud tops had warmed and become elongated,
but subsequently the cloud tops had cooled and become more symmetrical
and the eye had warmed once more. This fluctuation was attributed to
an eyewall replacement cycle as well as some shear. In spite of this,
Ioke's MSW remained at 140 kts. The hurricane weakened below Category 5
status for 12 hours beginning at 26/0000 UTC as winds dropped to 130 kts,
but the MSW was bumped back to 140 kts at 1200 UTC. This fluctuation in
intensity was also attributed to an eyewall replacement cycle. Hurricane
Ioke was the 5th Category 5 hurricane on record in the Central North
Pacific, and the first to form and achieve this distinction in that
region. Hurricanes Emilia, Gilma and John of 1994 all moved in from
the Eastern Pacific, and Typhoon Patsy of 1959 came from the Western
Pacific.
The cyclone was by this time tracking to the west-southwest as
pressures to the north increased. Ioke was south of a huge anticyclone
in the mid-Pacific which was flanked by anomalously strong mid and upper-
level cyclones near 150W and 155E. This configuration resulted in low
shear and a favorable outflow pattern, and in conjunction with warm SSTs,
set the stage for Ioke to maintain itself as a very intense cyclone for
many more days. The west-southwesterly motion continued and the intense
Hurricane Ioke reached the International Dateline on 27 August still at
Category 5 intensity. CPHC issued their final advisory on Ioke at
27/0300 UTC with JTWC and JMA assuming responsibility for the 27/0600 UTC
warnings. The first JTWC warning placed the center of Ioke about 785 nm
east of Wake Island, or about 675 nm south-southwest of Midway Island.
Typhoon-force winds extended outward 55-60 nm from the center with gales
covering a zone about 300 nm in diameter.
(4) Dateline to Wake Island
---------------------------
The west-southwesterly motion continued through 0000 UTC on 29 August
when Ioke "bottomed out" in latitude near 16.0N/174.2E. The storm had
re-attained Category 5 status at 26/1200 UTC and a MSW of 140 kts was
maintained for 36 hours. The intensity was lowered to 135 kts at 0000
UTC on the 28th and further to 130 kts six hours later, but Ioke remained
at or above super typhoon intensity (130 kts) through this period.
Increased upper-level inflow from a ridge to the northwest was blamed
for the slight weakening trend. Super Typhoon Ioke was upgraded back
to 140 kts at 29/1800 UTC while centered approximately 340 nm east-
southeast of Wake Island. The west-northwesterly motion had resumed
and Ioke was making a beeline for the tiny island. Even before the
storm had reached the Dateline some of the models were hinting that
Wake Island might eventually lie in its path.
Ioke's final stint as a Category 5 typhoon lasted for 18 hours and
the intensity was brought down slightly to 135 kts at 30/1200 UTC, but
the storm remained a formidable super typhoon as it closed in on small
Wake Island. At 31/0000 UTC Ioke's center was about 110 nm east-
southeast of the island, and by 0600 UTC had closed to about 45 nm to
the east. However, the track had turned more to the northwest (at
10 kts) and this slight turn kept the center of the eye just to the
north of Wake Island. At 31/1200 UTC the center had moved to a point
30 nm northwest of the island, and this distance had increased to 90 nm
by 1800 UTC. Ioke's estimated MSW remained at 135 kts during its close
approach to Wake Island. (Impacts to Wake Island will be discussed in
Section D below.)
(5) Wake Island to Alaska
-------------------------
Ioke was not to remain a super typhoon for much longer after passing
Wake Island. By 1200 UTC on 1 September the eye had become cloud-filled
and oblong in shape. Entrainment of drier mid-level air along with an
increase in vertical shear were responsible for the weakening. The
MSW was lowered from 130 kts to 115 kts in the 1200 UTC warning, but
held steady there for another 18 hours, followed by very slow weakening.
The cyclone continued moving on a west-northwest to northwesterly track
in the general direction of Japan. By 3 September Ioke was moving to
the north-northwest from a position about 820 nm southeast of Tokyo.
The weakening process began to accelerate on the 3rd with Ioke's MSW
dropping from 100 kts at 03/0600 UTC to minimal typhoon intensity of
65 kts at 04/1200 UTC. As is often the case with typhoons beginning to
undergo extratropical transition, JMA's 10-min avg MSW estimates were
higher than the 1-min avg values reported in JTWC's warnings.
JTWC downgraded Ioke to a 60-kt tropical storm at 05/0000 UTC with
the system moving northward at 17 kts. JMA, however, maintained Ioke
at typhoon intensity for another 24 hours. At 0600 UTC the center of
Ioke passed about 375 nm due east of Tokyo. Six hours later JTWC
issued their final warning on the storm, which was by now tracking
northeastward at 23 kts ahead of an approaching trough. In JTWC's
estimation Ioke was beginning to transition into an extratropical
cyclone, but JMA continued to classify Ioke as a tropical cyclone until
0000 UTC on the 7th when it was in the Bering Sea barreling northeastward
at 45 kts. By 07/1200 UTC the former super typhoon's remnants had
crossed the Dateline and were dropped from JMA's marine warnings. Based
on information found in the online Wikipedia report (see Section D
below), Ioke�s remnants continued eastward and apparently moved over
portions of Alaska.
C. Meteorological Observations
------------------------------
Around 0300 UTC on 31 August the center of Super Typhoon Ioke passed
over buoy 52609, apparently located a short distance east of Wake Island.
This buoy does not report wind speed, but reported a minimum SLP of
921.5 mb as the eye passed directly over the buoy. An anemometer on
Wake Island reported sustained winds of 68 kts, gusting to 87 kts, at
31/0618 UTC, but the instrument ceased reporting after this time. A
barometer on the island reported a SLP of 934 mb at 31/0906 UTC.
D. Damage and Casualties
------------------------
On Johnston Atoll, twelve (some accounts say 13) persons aboard a
U. S. Air Force vessel safely rode out the storm in a hurricane-proof
bunker on the island. Five of the 12 were crew members, and the other
seven were contractors hired by the Air Force to perform repair work on
the island. Johnston Island was formerly a U. S. military outpost, but
is now a wildlife refuge and normally uninhabited most of the time. A
fly-over of the island the next day revealed surprisingly little damage.
The few trees on the island were still standing and flocks of adult birds
were seen flying around.
As it became apparent that Super Typhoon Ioke would pose a serious
threat to Wake Island, the island's 188 residents were evacuated by
air to Hawaii. A reconnaissance mission flown over Wake Island by the
U. S. Coast Guard after Ioke had passed revealed blown-off roofs and
downed trees--in general, overall moderate damage, but considered
repairable.
JMA issued evacuation orders for its staff on the Japanese island of
Minami Torishima with the approach of the typhoon on 1 September, but
no damage has been reported.
And finally, the extratropical remnants of Ioke produced 7.6-meter
waves and a severe storm surge along the western Alaskan coastline,
resulting in severe beach erosion. The former typhoon produced heavy
rainfall and 25 to 35-kt winds over the state on 7 September. Rainfall
totaled 29.2 mm in Bethel and contributed to above normal rainfall totals
for the month of September in Juneau.
Some of the above information (especially the final paragraph) was
gleaned from the Wikipedia report on Ioke, which also has many links to
sites where additional information may be obtained. The URL is:
http://en.wikipedia.org/wiki/Hurricane_Ioke>
(Report written by Gary Padgett)
HURRICANE ILEANA
(TC-10E)
21 - 27 August
------------------------------------
Sometime around mid-August a tropical wave emerged into the Eastern
Pacific and gradually began to show signs of development. By 1200 UTC
on 21 August convection had become organized sufficiently to be
classified as a tropical depression and warnings were initiated on
Tropical Depression 10E at 1500 UTC. The depression was then located
about 300 nm south-southwest of Acapulco. The new depression quickly
strengthened and was upgraded to Tropical Storm Ileana at 2100 UTC.
Ileana embarked on a remarkably straight west-northwest to northwesterly
track which it followed throughout its lifetime. Strengthening
continued and Ileana reached hurricane intensity around 1800 UTC on
22 August while centered approximately 300 nm southwest of Manzanillo,
Mexico. The storm intensified rapidly, reaching Category 3 status
on the Saffir/Simpson scale at 23/0600 UTC and peaking at 105 kts six
hours later while centered about 325 nm south-southwest of Cabo San
Lucas.
Following its peak intensity Ileana continued on its northwesterly
course and gradually began to weaken. Ileana's initial weakening was
in part due to an eyewall replacement cycle, but the storm was prevented
from re-intensifying due to movement over increasingly cooler waters.
The hurricane was downgraded to a 55-kt tropical storm at 0900 UTC on
26 August while located approximately 450 nm west of Cabo San Lucas,
and was further downgraded to a tropical depression 24 hours later.
The final TPC/NHC advisory, issued at 27/1500 UTC, placed the weakening
system roughly 600 nm west of Cabo San Lucas. By later in the day it
had deteriorated into a large remnant LOW which drifted westward for
a few more days before losing its identity.
No damage or casualties have been attributed to Hurricane Ileana.
(Report written by Gary Padgett)
HURRICANE JOHN
(TC-11E)
28 August - 4 September
-------------------------------------------
Hurricane John became the first Eastern Pacific hurricane to make
landfall in Mexico since Hurricane Marty in September, 2003. A tropical
wave entered the Eastern North Pacific on 25 August and almost
immediately began to show signs of organization. However, the system
did not develop into a tropical depression until 1200 UTC on the 28th
when it was located about 200 nm south of Salina Cruz, Mexico. The
first advisory on Tropical Depression 11E was issued at 1500 UTC, and
at 2100 UTC Tropical Storm John was christened. John began moving on
a west-northwesterly track parallel to the coast of Mexico and steadily
intensified, becoming an 80-kt hurricane by 29/1800 UTC when located
about 165 nm south-southeast of Acapulco. John actually underwent an
episode of rapid intensification on the 29th with its MSW increasing
from 60 kts to 100 kts in twelve hours. By 1800 UTC on 30 August John
had become a Category 4 hurricane about 165 nm west of Acapulco with
winds estimated at 115 kts--the peak for the hurricane's history.
Hurricane John subsequently underwent an eyewall replacement cycle
which, in conjunction with land interaction as the storm moved very
near the coast, led to a gradual weakening of the cyclone. Although
the eye remained offshore, the storm's circulation affected portions
of Mexico with very heavy rains and strong winds. Significant storm
surge flooding was reported in Acapulco. As the hurricane rounded
Cabo Corrientes, its track bent slightly more toward the northwest,
drawing a bead on the Cabo San Lucas area. Fortunately, however, John
had weakened to a 90-kt Category 2 hurricane by 0000 UTC on 1 September.
After moving further away from the Mexican mainland, the winds increased
to 100 kts briefly at 01/1200 UTC, but soon began to drop again due to
another eyewall replacement cycle. John's track continued to bend ever
so slightly to the northwest, sparing the Cabo area. However, areas
further north on the eastern side of the Baja Peninsula were not so
lucky.
Hurricane John's eye made landfall near Cabo del Este around 0300
UTC on 2 September with the MSW estimated at 95 kts. The eye of John
passed very near La Paz around 02/0900 UTC with winds having weakened
to near 85 kts. The storm continued moving north-northwestward along
the eastern Baja coastline and eventually made a second landfall (after
crossing the Bahia La Paz) as a Category 1 hurricane. Once inland over
the Peninsula, John continued to slowly weaken and was downgraded to a
tropical storm at 02/2100 UTC. The center remained near the Gulf of
California and weakening proceeded rather slowly. John was finally
downgraded to a tropical depression at 0000 UTC on 4 September about
45 nm (80 km) northwest of Santa Rosalia, Mexico. Later that morning
TPC/NHC issued the final advisory on John. Most of the convection had
decoupled from the circulation and was moving towards the mainland and
a clear LLCC had not been discernible for 24 hours.
Hurricane John had adverse effects on widespread regions of Mexico.
Storm surge flooding and strong winds left damage in the Acapulco area,
and a significant portion of the western coast of mainland Mexico
experienced heavy rainfall, which led to flooding and landslides.
Many trees were downed in the La Paz area with 200 homes completely
destroyed. Thousands of poorly-constructed houses were destroyed in
the Baja California region. In Ciudad Juarez, across the border from
El Paso, Texas, rainfall from the storm's remnants led to flooding,
downed power lines, and was responsible for several traffic accidents.
Total damage in Mexico from the storm amounted to $60.8 million (USD)
with six fatalities attributed to Hurricane John.
Some of the above information was taken from the excellent online
Wikipedia report on Hurricane John, accessible at the following URL:
http://en.wikipedia.org/wiki/Hurricane_John_%282006%29>
(Report written by Gary Padgett)
HURRICANE KRISTY
(TC-12E)
30 August - 8 September
-------------------------------------------
The final tropical cyclone of a very busy August began with an area
of disturbed weather associated with a tropical wave. The system was
upgraded to Tropical Depression 12E at 0300 UTC on 30 August while
centered about 475 nm south-southwest of Cabo San Lucas. TD-12E quickly
intensified and was upgraded to Tropical Storm Kristy six hours later.
The intensification trend continued as Kristy moved northwestward far
to the southwest of the Baja California Peninsula. The cyclone was
upgraded to hurricane status at 0900 UTC on the 31st based upon Dvorak
ratings ranging from T3.5 to T4.5, plus a couple of microwave passes
indicating a possible developing eyewall. Kristy remained a hurricane
for 24 hours, but never intensified above minimal hurricane strength of
65 kts. By the morning of 1 September cloud top temperatures near the
center were warming as the cyclone began losing its deep convection.
Concurrently, the cloud mass was becoming less organized, so Kristy was
downgraded to a tropical storm at 01/0900 UTC. Continued weakening was
forecast due to cooler SSTs and increased vertical shear from strong
Hurricane John located not too far to the east.
By 2 September steering currents had become weak and Kristy meandered
for the next couple of days, drifting to the south and southeast. The
cyclone had become situated under an outflow channel of Hurricane John
and the resultant east to east-southeasterly shear led to further
weakening. Kristy was downgraded to a tropical depression at 2100 UTC
on the 2nd about 550 nm west-southwest of Cabo San Lucas. Continued
weakening and dissipation in two days was forecast, but surprises always
happen with tropical cyclones. By the afternoon of the 3rd an area of
strong convection had developed with cloud top temperatures below -70 C,
so Kristy was re-upgraded to tropical storm intensity at 03/2100 UTC.
No further strengthening was anticipated, and the forecast called for
dissipation in three days. This new forecast seemed to be verifying
as Kristy was downgraded back to depression status twelve hours later.
However, never say never! As the 4th progressed Tropical Depression
Kristy began a slow but steady trek to the west as a subtropical ridge
to the north began to build. Early on the 5th a strong burst of
convection occurred near the center and persisted for several hours.
Dvorak T-numbers once more increased to tropical storm strength, so
the tenacious Kristy was upgraded to tropical storm status for the third
time, being centered about 740 nm west-southwest of Cabo San Lucas.
By afternoon the convective bursts had morphed into bands, giving the
appearance of an intensifying tropical cyclone. Based on satellite
intensity estimates, Kristy's intensity was bumped up to 40 kts at
05/2100 UTC. Further intensification up to 50 kts was forecast within
24 hours. However, the extent and depth of the convection soon began
to diminish and Kristy's MSW was lowered back to 35 kts at 06/0300 UTC.
With Kristy's history of intensity fluctuations, some further modest
strengthening was forecast, but this failed to materialize.
Entrainment of dry, stable air from the northwest led to a continued
decrease in deep convection, in spite of still-warm SSTs and light shear,
and Kristy was downgraded to a tropical depression for the final time
at 06/2100 UTC. The system continued to moved slightly south of west
for the next couple of days as it slowly spun down. Since the forecast
track kept Kristy over marginally warm SSTs with low shear, the 07/0300
UTC advisory called for Kristy to maintain itself as a 30-kt depression
for several more days. However, by 0300 UTC on the 8th Kristy had been
devoid of organized deep convection for more than 24 hours so TPC/NHC
issued the final advisory at that time, placing the center approximately
1300 nm west-southwest of Cabo San Lucas.
No deaths or damages have been attributed to Hurricane Kristy.
(Report written by Gary Padgett)
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for August: 3 tropical depressions **
3 tropical storms
2 typhoons ++
2 super typhoons &&
** - two of these were classified as weak depressions by JMA only
++ - one of these formed in late July and continued into early August
&& - one of these was a visitor from the Central North Pacific and
continued into early September
Sources of Information
----------------------
Most of the information presented below is based upon tropical
cyclone warnings and significant tropical weather outlooks issued
by the Joint Typhoon Warning Center of the U. S. Air Force and
Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion
tropical cyclone tracks file, I normally annotate track coordinates
from some of the various Asian warning centers when their center
positions differ from JTWC's by usually 40-50 nm or more. All
references to sustained winds imply a 1-minute averaging period
unless otherwise noted.
Michael V. Padua of Naga City in the Philippines, owner of the
Typhoon 2000 website, normally sends me cyclone tracks based upon
warnings issued by the Japanese Meteorological Agency (JMA) and the
Philippines' Atmospheric, Geophysical & Astronomical Services
Administration (PAGASA). A very special thanks to Michael for the
assistance he so reliably provides.
In the title line for each storm I have referenced all the cyclone
names/numbers I have available: JTWC's depression number, the
JMA-assigned name (if any), JMA's tropical storm numeric designator,
and PAGASA's name for systems forming in or passing through their
area of warning responsibility.
Northwest Pacific Tropical Activity for August
----------------------------------------------
The tropical Western Pacific was very active during the first half
of August with five named storms forming within a 9-day period. In
addition, during the first few days of the month Typhoon Prapiroon,
which had formed at the end of July, was active in the northern South
China Sea where it made landfall in southern China on the 3rd. The
complete report on Prapiroon may be found in the July summary.
Maria was a storm of higher-latitude origin which managed to reach
minimal typhoon intensity (per JTWC's analysis). Maria later recurved
sharply just south of Honshu and brushed the southern coast of that
island as it accelerated northeastward. Super Typhoon Saomai and
Tropical Storm Bopha both formed in the monsoon trough at about the same
time of Maria's genesis, and all three cyclones operated concurrently
for a few days. Bopha remained a fairly weak tropical storm as it moved
westward toward Taiwan. The large, intense Saomai gave the weakening
Bopha a push which sent it moving southwestward into the northern South
China Sea. Saomai followed a classic 'straight-runner' track from deep
in the tropics west-northwestward through the Marianas, passing just
north of Taiwan, and finally smashing into eastern China still at super
typhoon intensity. Saomai was reported to be the strongest typhoon to
strike the Chinese mainland in modern times. More than 400 persons lost
their lives with damage in the billions of yuan.
Wukong and Sonamu were two tropical storms spawned by a large
monsoon gyre. Wukong, the stronger of the two, formed just west of
the Marianas and followed a generally northwesterly, albeit erratic,
track toward Japan. The storm eventually crossed the island of Kyushu
and moved up the eastern side of the Korean Peninsula. Tropical Storm
Sonamu formed just east of northern Luzon and moved fairly rapidly
northeastward, later swinging to the north as it underwent a Fujiwhara
interaction with Wukong. As it neared Japan, Sonamu weakened and was
absorbed into Tropical Storm Wukong.
On 27 August a visitor from the Central North Pacific, Category 5
Hurricane Ioke, entered the Northwest Pacific basin. Designated as
Super Typhoon Ioke, the large, intense cyclone continued on a west-
northwesterly track toward tiny Wake Island. Ioke passed just north
of the island on the 31st and continued moving in the general direction
of Japan as it slowly began to weaken. The cyclone eventually recurved
east of Honshu and became extratropical on 5 September with the remnants
later affecting the Aleutian Islands and Alaska. The complete report
on Ioke is contained in the preceding section of this summary covering
the Northeast Pacific basin.
There were three weaker systems during the month classified as
tropical depressions by the various warning agencies. Two of these
were mentioned only in JMA's high seas bulletins as weak systems. Both
formed and moved north of 30N, suggesting that they were likely
subtropical in nature. The first was located near 30.0N/174.0E at
15/0600 UTC and moved very slowly westward, being last referenced near
31.0N/170.0E at 17/1800 UTC. The second system was located at 21/1800
UTC near 33.0N/155.0E. Twenty-four hours later the final reference to
this system placed it near 34.0N/152.0E. Winds in these systems likely
did not exceed 20-25 kts and no tracks were given in the companion
cyclone tracks file.
The final system of August was a short-lived tropical depression
designated as TD-13W by JTWC and carried by JMA and some of the other
warning offices. The depression formed in the northern South China
Sea on 23 August and moved generally northward, moving inland in
China between Hainan and Hong Kong around 24/1800 UTC. The peak MSW
estimated by JTWC was 30 kts at 24/1800 UTC, shortly before the center
made landfall. In JMA's high seas bulletins the depression was
referenced only in the summary section, implying 10-min avg winds of
probably no higher than 25 kts. A track was included for TD-13W in
the cyclone tracks file.
Reports for Typhoon Maria, Super Typhoon Saomai, and Tropical Storms
Bopha, Wukong and Sonamu, all written by Kevin Boyle, follow. Reports
on Typhoon Prapiroon and Super Typhoon Ioke may be found elsewhere, as
noted above.
The online Wikipedia reports for the Northwest Pacific cyclones may
be accessed at the following URL:
http://en.wikipedia.org/wiki/2006_Pacific_typhoon_season>
A more detailed report is available for Super Typhoon Saomai/Juan.
The link is included in the report for that cyclone.
TYPHOON MARIA
(TC-09W / STS 0607)
4 - 12 August
---------------------------------------
Maria: contributed by the United States, is the Latin/Hispanic form
of Mary and is popular as a Chamorro woman's name
A. Storm Origins
----------------
The second of six tropical cyclones during the month of August, Maria
was a TUTT-induced tropical cyclone that formed at a fairly high
latitude. After its initial mention in JTWC�s STWO on 3 August, the
system slowly developed over the next two days while drifting towards
the west-northwest, and at 1630 UTC 5 August a TCFA was issued. (JMA
had started the system as a weak tropical depression at 04/0000 UTC
while located approximately 400 nm east-northeast of the northern
Mariana Islands and had upped the MSW to 30 kts six hours later.)
Remarks in JTWC�s TCFA include: �. . . recent animated satellite imagery
depicts a dramatic flare-up in deep convection slightly east of a
well-defined low level circulation center. Further satellite analysis
indicates that despite this increase in convective organization this
system still exhibits characteristics of a subtropical cyclone. Upper-
level analysis reveals low to moderate vertical wind shear and
favourable diffluence aloft. . .� The first warning on Tropical
Depression 09W was issued at 1800 UTC 5 August with the centre located
approximately 150 nm east-northeast of Iwo Jima. The system had been
named Maria at 05/1200 UTC when JMA raised their 10-min avg MSW to
35 kts.
B. Synoptic History
-------------------
Continuing west-northwestwards along the southwestern flank of a
broad subtropical ridge east of Japan, Maria was quickly upgraded to
a 40-kt tropical storm at 06/0000 UTC and relocated to a position
150 nm north-northeast of Iwo Jima. Tropical Storm Maria intensified
as it moved northwestwards and reached 60 kts at 06/0600 UTC. A
06/1045 UTC SSMI pass depicted a symmetric banding eye with deep
convection over the eastern semicircle. Maria was upgraded to a 65-kt
typhoon at 07/1200 UTC while located approximately 305 nm south-southwest
of Tokyo, Japan, but maintained this intensity for only six hours.
Turning northward on 8 August, Maria began to weaken as it encountered
drier air and increasing wind shear. After recurving sharply just shy
of the southeastern coast of Honshu, the weakening tropical cyclone
passed just south of Tokyo early on 9 August. JTWC issued the final
warning at 09/0000 UTC while JMA maintained Maria�s identity as a
tropical cyclone until 11/0000 UTC when that agency issued their final
bulletin. The system was then located about 450 nm east-northeast of
Tokyo. The remnant extratropical gale continued slowly east-
northeastward, and was last referenced in JMA�s high seas bulletins at
12/1200 UTC when located several hundred miles east of Hokkaido.
The maximum 10-min avg MSW assigned by JMA for Maria was 60 kts and
the estimated minimum CP was 975 mb.
C. Damage and Casualties
------------------------
There were no reports of damages or casualties associated with Maria.
A tidbit of information obtained from the Hong Kong Observatory�s
Overview of Tropical Cyclones in August, 2006, indicated that five
passengers were injured when an aircraft heading for Tokyo encountered
turbulence associated with Maria.
(Report written by Kevin Boyle)
SUPER TYPHOON SAOMAI
(TC-08W / TY 0608 / JUAN)
4 - 11 August
---------------------------------------------
Saomai: contributed by Vietnam, is the Vietnamese name for the planet
Venus
A. Introduction and Storm Origins
---------------------------------
Super Typhoon Saomai co-existed with two other tropical cyclones in
the Northwest Pacific during the first part of August and was by far
the most intense. Forming in the eastern portion of the monsoon trough
on 4 August, Saomai followed a �straight-runner� style track across the
Northwest Pacific basin and underwent a binary interaction with Tropical
Storm Bopha (TC-10W). Saomai, much larger than Bopha, was little
affected by this interaction, and continued its west-northwestward track
into China on 10 August. It was described as the most powerful typhoon
ever to make landfall over mainland China, and was the strongest to hit
the country since Typhoon Wanda in 1956. Its impact was devastating,
especially in the areas already badly hit by Tropical Storm Bilis and
Typhoon Kaemi in July.
First mention of this monstrous storm was in JTWC�s STWO issued at
0600 UTC 2 August when an area of convection persisted approximately
125 nm south-southeast of Pohnpei. This statement in part: �Animated
multi-spectral imagery reveals a strong band of convergent westerly
flow on the southern periphery of an elongated low-level circulation
center. This convergent axis has been the focal point for deep
convection over the last 12 hours. The disturbance is located on the
equatorward side of an upper-level ridge axis in a region of favorable
divergence aloft and moderate vertical wind shear.� The system slowly
organized as it drifted steadily northwestwards, and after the issuance
of a TCFA on 4 August, the first warning on Tropical Depression 08W was
issued at 1800 UTC 4 August. It was upgraded to a 35-kt tropical storm
at 05/0600 UTC, and named Saomai six hours later when JMA raised their
10-min avg MSW to 35 kts. At the time Tropical Storm Saomai was
located 135 nm southeast of Guam, moving northwestward at 11 kts.
B. Synoptic History
-------------------
Drifting northwestwards, Tropical Storm Saomai slowly intensified and,
after passing just north of Guam late on 5 August, was upgraded to a
65-kt typhoon at 1200 UTC 6 August. Changing onto a west-northwesterly
track, Saomai continued to gradually strengthen, reaching an intensity
of 75 kts on 7 August. As Typhoon Saomai approached the southern Ryukyu
Islands late 8 August, it began to intensify more rapidly, reaching its
peak intensity of 140 kts at 09/1200 UTC and becoming the third super
typhoon of 2006 in the Northwest Pacific basin. Remarkably, Saomai
maintained its maximum intensity until early on 10 August before slowly
beginning to weaken. Turning westward, Typhoon Saomai passed north of
Taiwan and crossed the Chinese coast near Fu�an at 10/0923 UTC (based on
an AMSU pass) with the MSW estimated at 130 kts. Once inland, the
tropical cyclone weakened quickly. The final warnings were issued by
JTWC and JMA at 10/1800 UTC and 11/0000 UTC, respectively.
During the time that Typhoon Juan was in PAGASA�s AOR, the peak MSW
(10-min avg) assigned by that agency was 75 kts from 09/0000 to 09/0600
UTC. JMA estimated a peak intensity of 95 kts (10-min avg) with a
minimum CP of 925 mb.
C. Damage and Casualties
------------------------
As was the case with Tropical Storm Bilis in July, the outer
rainbands from Saomai affected portions of the Philippines. Over 400
homes were reported destroyed by storm surge, and there were two
fatalities with seven others reported missing.
The strong core of Super Typhoon Saomai passed to the north of
Taiwan, but the island still experienced heavy rain and wind that
disrupted traffic and resulted in cancelled airline flights.
By far the biggest impact of the typhoon was felt on the Chinese
mainland where 441 deaths were reported and damage exceeding $1.5
billion (USD) was sustained. In advance of Saomai�s arrival over 1.5
million people were evacuated to storm shelters in Zhejiang and Fujuan
Provinces. Even though the storm�s center made landfall in Zhejiang
Province, the neighboring province of Fujian sustained even greater
damage and experienced more fatalities. Two persons were reported
killed in Jiangxi Province.
Much more information on the effects of Typhoon Saomai in China
may be found in the online Wikipedia report at the following URL:
http://en.wikipedia.org/wiki/Typhoon_Saomai_%282006%29>
(Report written by Kevin Boyle and Gary Padgett)
TROPICAL STORM BOPHA
(TC-10W / STS 0906 / INDAY)
5 - 11 August
-----------------------------------------------
Bopha: contributed by Cambodia, is the name of a flower which is used
as a little girl's name
A. Storm Origins
----------------
Tropical Storm Bopha was one of three tropical cyclones co-existing
in the Northwest Pacific basin during the first week of August. It
reached a peak intensity of 50 kts before crossing Taiwan on 8 August.
Interaction with Super Typhoon Saomai caused Bopha to dip sharply
southwestwards before it dissipated on 10 August. (Editor's Note: The
other two simultaneous TCs in addition to Bopha were Super Typhoon Saomai
and Typhoon Maria. Interestingly, in September, 2000, Tropical Storm
Bopha and Super Typhoon Saomai were also part of a simultaneous three-
storm outbreak, but in that year the third member of the party was
Typhoon Wukong.)
An area of convection developed and persisted about 560 nm
southeast of Okinawa on 4 August. The flare-up of convection was
association with surface troughing, and an upper-level anticyclone was
located over the disturbance with low vertical shear over the region.
The system was first referenced in JTWC's STWO at 2200 UTC 4 August, and
JMA classified the system as a weak tropical depression in their high
seas bulletin issued at 05/0600 UTC. A later STWO issued at 06/0600 UTC
remarked: "Recent multi-spectral imagery and a 05/2330 UTC SSMI pass
depict a well-defined low-level circulation center with deep convection
located 90 nm east of the center. Upper-level analysis indicates a
favourable environment with weak (5-10 kts) vertical wind shear. A
synoptic ship report 120 nm southwest of the center indicated a 1002 mb
SLP". The first warning on Tropical Depression 10W closely followed
this statement at 06/0600 UTC and located the centre approximately
320 nm southeast of Naha, Okinawa. At the same time JMA raised their
10-min MSW to 35 kts and named the system Bopha.
B. Synoptic History
-------------------
Drifting west-northwestward at 8 kts, Tropical Depression Bopha was
upgraded to a 40-kt tropical storm at 06/1200 UTC. After further
intensification, Bopha reached its maximum intensity of 50 kts at 0600
UTC 7 August while passing 200 nm south of Naha, Okinawa. At this time,
Typhoon Saomai was tracking steadily west-northwestward and was located
a little over 600 nm to the east of Bopha.
Embedded in the steering flow south of a deep-layer ridge to the
north, Bopha continued westward and began to gradually weaken due to
increasing wind shear. By the time the storm made landfall over Taiwan
late on 8 August, the MSW had dropped to 35 kts. After clearing Taiwan,
Bopha was downgraded to a tropical depression at 09/0600 UTC.
Influenced by the larger circulation of Super Typhoon Saomai, the weak
tropical cyclone then made a sharp southwestward turn a little over
100 nm east-southeast of Hong Kong, China. The fully-exposed LLCC then
began to meander slowly westwards on 10 August. The final JTWC warning
on the dissipating system was issued at 10/1200 UTC, while JMA continued
to follow the weakening depression through 11/0000 UTC when it was
located very near Hong Kong.
The highest MSW and lowest CP estimated by JMA were 50 kts and 985 mb,
respectively. During the time that Bopha was within PAGASA's AOR, where
it was known as Tropical Storm Inday, the peak 10-min avg MSW estimated
by that agency was 45 kts.
C. Damage and Casualties
------------------------
Even though Bopha affected Taiwan, there were no reports of damage or
casualties.
(Report written by Kevin Boyle)
TROPICAL STORM WUKONG
(TC-11W / TS 0610)
12 � 21 August
-----------------------------------------
Wukong: contributed by China, is the king of the monkeys. Featured in
the classic novel 'Journey to the West'.
A. Introduction and Storm Origins
---------------------------------
Tropical Storm Wukong was one of two tropical cyclones generated by a
monsoon gyre in the northwest Pacific during mid-August. After peaking
at 50 kts and interacting with Tropical Storm Sonamu and absorbing its
remnants, Wukong made landfall over Kyushu. It took over 24 hours for
the tropical cyclone�s circulation to cross the Japanese island.
Tropical Storm Wukong stemmed from a disturbance located in the
monsoon cloud band which had wrapped around the northern side of a gyre.
Remarks in JTWC�s TCFA at 0230 UTC 12 August include: �Recent animated
multi-spectral imagery reveals a consolidating low-level circulation
center (LLCC), and a 12/0000 UTC synoptic ship observation report
indicates winds associated with the LLCC to be at least 20 knots.
Upper-level analysis indicates favorable outflow into a Tropical Upper-
Tropospheric Trough (TUTT) cell to the northwest of the LLCC, as well
as low vertical wind shear.� The system was moving northwestward at
9 kts with a MSW of 20 to 25 kts. The first warning on Tropical
Depression 11W at 12/1200 UTC positioned the centre approximately 75 nm
south of Iwo Jima. Tracking north-northwestward, TD-11W was upgraded
to a 35-kt tropical storm at 13/0000 UTC and named Wukong six hours
later when JMA raised their 10-min avg MSW to 35 kts.
B. Synoptic History
-------------------
Tropical Storm Wukong slowed dramatically on 13 August as a ridge
built eastward over Japan. Slow, erratic movement persisted through
14 August as the tropical cyclone gradually strengthened to its peak
intensity of 50 kts at 14/1800 UTC while located approximately 545 nm
southeast of Sasebo, Japan. Wukong began to accelerate to the north-
northwest on 15 August while commencing a binary interaction with
Tropical Storm Sonamu (TC-12W). This interaction caused Wukong to
drift west-southwestwards on 16 August. After the demise of TS Sonamu,
Wukong turned back to the northwest as a weakness developed in the
steering ridge. The system maintained a MSW of 45 kts for two days as
it continued slowly northwestwards towards Japan. Tropical Storm Wukong
made landfall near Miyazaki city and trudged slowly across the Japanese
island of Kyushu on 18 August. The storm remained over land for over
24 hours and did not emerge into the Sea of Japan until 19 August. JTWC
downgraded Wukong to a tropical depression at 18/0600 UTC and issued the
last warning at 19/0000 UTC. JMA maintained tropical storm intensity on
19 August as Wukong brushed the eastern coasts of North/South Korea,
downgrading it to tropical depression status at 20/1200 UTC. The weak
residual depression drifted northeastwards across the Sea of Japan and
was last referenced at 21/1800 UTC when located west of extreme
southern Hokkaido.
The maximum 10-min avg MSW and minimum CP estimated by JMA were
45 kts and 980 mb, respectively.
C. Damage and Casualties
------------------------
On 18 August Tropical Storm Wukong brought torrential rains to
Kyushu, resulting in at least three deaths, disruption of air flights,
and power outages.
(Report written by Kevin Boyle)
TROPICAL STORM SONAMU
(TC-12W / TS 0611 / KATRING)
13 - 16 August
------------------------------------------------
Sonamu: Korean word for pine tree, contributed by the Democratic
People's Republic of Korea (North Korea)
A. Introduction and Storm Origins
---------------------------------
Tropical Storm Sonamu was a relatively short-lived tropical cyclone
which was generated on the southern flank of a monsoon gyre. Embedded
in a rather strong steering flow, Sonamu raced northeastwards and
peaked at 45 kts. Interaction with Tropical Storm Wukong (TC-11W)
caused the tropical cyclone to weaken and dissipate several hundred
miles southeast of Japan.
A Tropical Cyclone Formation Alert issued at 1730 UTC 13 August noted
that the area of convection was located approximately 430 nm east-
northeast of Manila, Philippines, and moving slowly eastward at 4 kts.
Animated infrared imagery revealed enhanced convection consolidating
near an elongated LLCC. Upper-level analysis indicated favourable
divergence and low to moderate wind shear. Accelerating eastwards, the
system developed into Tropical Depression 12W at 13/1800 UTC. It was
named Sonamu at 14/0000 UTC after JMA raised their MSW estimate to
35 kts. JTWC upgraded Sonamu to a 40-kt tropical storm six hours later
when the system was centred approximately 500 nm south-southeast of
Okinawa.
B. Synoptic History
-------------------
Tropical Storm Sonamu was steered northeastwards around the periphery
of the monsoon gyre and strengthened to its peak intensity of 45 kts at
1800 UTC 14 August while located approximately 485 nm southeast of
Naha, Okinawa. The storm began to weaken on 15 August as it turned
northeastward and began to interact with the almost stationary
Tropical Storm Wukong (TC-11W), located to the north-northwest. After
satellite imagery revealed that shear associated with the outflow of
Wukong had dramatically decreased the deep convection over Sonamu, JTWC
downgraded the system to a tropical depression at 15/1800 UTC. JTWC
issued the final warning at 16/0000 UTC on the dissipating tropical
cyclone which was racing north at 32 kts and about to be absorbed into
the circulation of Tropical Storm Wukong just south of Japan.
JMA estimated a maximum intensity of 40 kts (10-min avg) and a minimum
CP of 992 mb while PAGASA issued warnings on Tropical Storm Katring
(the PAGASA name) from 13/1800 UTC to 15/0000 UTC and estimated a peak
intensity of 35 kts (10-min avg).
C. Damage and Casualties
------------------------
No damage or casualties are known to have resulted from Tropical
Storm Sonamu.
(Report written by Kevin Boyle)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for August: 3 depressions
1 deep depression
North Indian Ocean Tropical Activity for August
-----------------------------------------------
The month of August normally is one of the quietest in the Bay of
Bengal and Arabian Sea, falling in between the more active periods of
the spring and fall transition seasons. Nonetheless, four systems were
classified as depressions by the India Meteorological Department (IMD)
during the month. The first was classified as a deep depression,
implying winds of 30 kts, whereas the other three were referred to as
simply depressions, implying winds no greater than 25 kts. A brief
synopsis of each system follows:
(1) Deep Depression of 1 - 5 August
-----------------------------------
A STWO issued by JTWC at 1800 UTC on 1 August noted that an area of
convection had persisted a couple hundred miles south-southeast of
Calcutta. Animated multi-spectral imagery and a 01/1248 UTC QuikScat
pass revealed that the LLCC of a monsoon depression had moved over
water in the northern Bay of Bengal. Strong northeasterly winds aloft
were inducing high vertical shear over the area, but were also providing
a good outflow mechanism for convective development. The system moved
westward across the northern Bay, and the IMD had classified it as a
depression by 02/0300 UTC when the center was located approximately
55 nm east-southeast of Chandbali. At 02/1200 UTC the IMD had upped
the system's classification to 'deep depression', implying winds of
30 kts. Around the same time JTWC upped the potential for development
to 'fair'. The center of the deep depression was near the Indian
coastline at that time, and by 0300 UTC the next day was moving inland
on the South Orissa coast between Puri and Gopalpur.
IMD followed the system inland for a couple of days as it moved into
central India. The peak winds were maintained at 30 kts for 24 hours
after the center had crossed the coast, suggesting that the system had
maintained much of its monsoon depression characteristics throughout
its lifetime. A track for this system was included in the companion
cyclone tracks file.
(2) Depression of 12 - 13 August
--------------------------------
The second depression formed on 12 August and at 0300 UTC lay centered
about 55 nm east-southeast of Balasore. The system moved in a west-
northwesterly direction and crossed the North Orissa coast near Balasore
around 1500 UTC. By 13/0300 UTC it had weakened into a low-pressure area
near Chattisgarh. This system was not referenced in any of JTWC's STWOs.
(3) Depression of 16 - 18 August
--------------------------------
The third depression of August formed on 16 August in the same general
area as the previous one, being centered at 16/0300 UTC about 80 nm
southeast of Balasore. The system subsequently moved westward and crossed
the North Orissa coast near Chandbali around 16/1450 UTC. After moving
inland the depression gradually weakened and was last referenced by
IMD at 0300 UTC on 18 August. JTWC mentioned this system in their STWOs,
assigning a 'fair' potential for development at one point, but this was
downgraded to 'poor' at 16/1800 UTC when the broad center was observed
to be moving inland.
(4) Depression of 29 August - 1 September
-----------------------------------------
The final depression to form in the northwestern Bay of Bengal during
August was located at 29/0300 UTC about 55 nm east-southeast of
Chandbali. The system moved rapidly west-northwestward and by 1200 UTC
had crossed the Orissa coast near Parandip. IMD continued following the
LOW inland across eastern and central India, last referencing it on
1 September when it was in the vicinity of Agra.
In the companion global cyclone tracks file prepared by the author,
a track was included for only the first of the NIO depressions. The
primary criterion for inclusion in the tracks file is reasonable evidence
of the existence of 1-min avg sustained winds of 30 kts or higher, either
reported by a warning agency or else a consensus of Dvorak ratings of
T2.0 or higher. IMD classified the latter three systems only as
'depressions', implying winds no higher than 25 kts.
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for August: No tropical cyclones
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for August: No tropical cyclones
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for August: No tropical cyclones
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for August: No tropical cyclones
*************************************************************************
SPECIAL FEATURE - SOURCES OF TROPICAL CYCLONE INFORMATION
The purpose of this section is to list some websites where many and
varied types of tropical cyclone information are archived. Many readers
will know about these already, but for the benefit of those who don't,
I wanted to include them.
(1) Aircraft Reconnaissance Information
---------------------------------------
Various types of messages from reconnaissance aircraft may be
retrieved from the following FTP site:
ftp://ftp.nhc.noaa.gov/pub/products/nhc/recon/>
Information regarding how to interpret the coded reconnaissance
messages may be found at the following URL:
http://www.nhc.noaa.gov/reconlist.shtml>
Links are also included to websites with further information about the
U. S. Air Force 53rd Weather Reconnaissance Squadron and the NOAA Air-
craft Operations Center.
(2) Archived Advisories
-----------------------
All the advisory products (public advisories, forecast/advisories,
strike probabilities, discussions, various graphics) issued by TPC/NHC
are archived on TPC's website. For the current year (using 2004 as an
example), the archived products can be found at:
http://www.nhc.noaa.gov/archive/2004/index.shtml>
Links to tropical products archives for earlier years are available at
the following URL:
http://www.nhc.noaa.gov/pastall.shtml>
JTWC warnings for past storms are archived on the NRL Monterrey website:
http://www.nrlmry.navy.mil/tc_pages/tc_home.html>
On the NRL site, the link to past years can be found in the upper left
corner of the screen.
I am not aware at the moment of any other TCWC which archives all
its tropical cyclone warning/advisory products for public access, but
if I learn of any, I will add them to this list.
(3) Satellite Imagery
---------------------
Satellite images of tropical cyclones in various sensor bands are
available on the NRL Monterrey and University of Wisconsin websites,
courtesy of Jeff Hawkins and Chris Velden and their associates. The
links are:
http://www.nrlmry.navy.mil/tc_pages/tc_home.html>
http://cimss.ssec.wisc.edu/tropic/tropic.html>
On the NRL site, the link to past years can be found in the upper left
corner of the screen. For the CIMSS site, a link to data archives is
located in the lower left portion of the screen.
Additional tropical satellite imagery, along with looping ability for
composite microwave imagery for the Western Hemisphere north of the
equator, can be found at:
(1) For the Eastern North Pacific:
http://www.ssd.noaa.gov/PS/TROP/trop-epac.html>
(2) For the Atlantic, Gulf of Mexico and Caribbean Sea:
http://www.ssd.noaa.gov/PS/TROP/trop-atl.html>
I'm sure there are other sites with available imagery available, and
as I learn of them, I will add the links to this list.
*************************************************************************
EXTRA FEATURE
In order to shorten the amount of typing in preparing the narrative
material, I have been in the habit of freely using abbreviations and
acronyms. I have tried to define most of these with the first usage
in a given summary, but I may have missed one now and then. Most of
these are probably understood by a majority of readers but perhaps a
few aren't clear to some. To remedy this I developed a Glossary of
Abbreviations and Acronyms which I first included in the August, 1998
summary. I don't normally include the Glossary in most months in
order to help keep them from being too long. If anyone would like to
receive a copy of the Glossary, please e-mail me and I'll be happy
to send them a copy.
*************************************************************************
AUTHOR'S NOTE: This summary should be considered a very preliminary
overview of the tropical cyclones that occur in each month. The cyclone
tracks (provided separately) will generally be based upon operational
warnings issued by the various tropical cyclone warning centers. The
information contained therein may differ somewhat from the tracking and
intensity information obtained from a "best-track" file which is based
on a detailed post-seasonal analysis of all available data. Information
on where to find official "best-track" files from the various warning
centers will be passed along from time to time.
The track files are not being sent via e-mail. They can be retrieved
from the archive sites listed below. (Note: I do have a limited e-mail
distribution list for the track files. If anyone wishes to receive
these via e-mail, please send me a message.)
Both the summaries and the track files are standard text files
created in DOS editor. Download to disk and use a viewer such as
Notepad or DOS editor to view the files.
The first summary in this series covered the month of October,
1997. Back issues can be obtained from the following websites
(courtesy of Michael Bath, Michael V. Padua, Michael Pitt, Chris
Landsea, and John Diebolt):
http://australiasevereweather.com/cyclones/>
http://www.typhoon2000.ph>
http://mpittweather.com>
ftp://ftp.aoml.noaa.gov/hrd/pub/landsea/padgett/>
http://www.tropicalcyclone2005.com/>
Another website where much information about tropical cyclones may
be found is the website for the UK Meteorological Office. Their site
contains a lot of statistical information about tropical cyclones
globally on a monthly basis. The URL is:
http://www.metoffice.gov.uk/weather/tropicalcyclone>
TROPICAL CYCLONE REPORTS AVAILABLE
JTWC now has available on its website the Annual Tropical Cyclone
Report (ATCR) for 2004 (2003-2004 season for the Southern Hemisphere).
ATCRs for earlier years are available also.
The URL is: http://199.10.200.33/jtwc.html>
Also, TPC/NHC has available on its webpage nice "technicolor"
tracking charts for the 2005 Atlantic and Eastern North Pacific
tropical cyclones; also, storm reports for all the 2005 Atlantic
and Eastern North Pacific cyclones are now available, as well as
track charts and reports on storms from earlier years.
The URL is: http://www.nhc.noaa.gov>
A special thanks to Michael Bath of McLeans Ridges, New South Wales,
Australia, for assisting me with proofreading the summaries.
PREPARED BY
Gary Padgett
E-mail: [email protected]
Phone: 334-222-5327
Kevin Boyle (Northwest Pacific)
E-mail: [email protected]
Simon Clarke (Northeast Australia/Coral Sea, South Pacific)
E-mail: [email protected]
*************************************************************************
*************************************************************************
|
Document: summ0608.htm
Updated: 23rd November 2006 |
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