Tropical Cyclones
[Index]
Tropical Cyclone LIUA : JTWC Advisories
Season 2018-2019 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH]
---> Tropical Cyclone LIUA Track Map and Data


WTPS21 PGTW 260130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 9.0S 157.8E TO 11.9S 161.8E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT
IMAGERY AT 260030Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 9.2S 158.4E. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 09
KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 91P) HAS PERSISTED NEAR
9.3S, 159.2E, APPROXIMATELY 96NM WEST OF HONIARA, GUADALCANAL.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 251958Z 91GHZ
SSMIS IMAGE DEPICT FRAGMENTED, FORMATIVE BANDING WRAPPING INTO A
CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC).  A RECENT 252321Z
PARTIAL ASCAT PASS REVEALS 25-30 KNOT WINDS IN THE WESTERN SEMI-
CIRCLE. THE ENVIRONMENTAL ANALYSIS INDICATES MODERATE (20-25 KNOT)
VERTICAL WIND SHEAR, STRONG DUAL OUTFLOW AND SUPPORTIVE SEA SURFACE
TEMPERATURES (28-29 CELSIUS). GLOBAL MODELS AGREE ON A SOUTHEASTERLY
TRACK TRAJECTORY. DYNAMIC MODELS REMAIN IN GENERAL AGREEMENT ON
POSSIBLE DEVELOPMENT WITHIN THE NEXT 12-36 HOURS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
270130Z.//
=========================================================================
WTPS31 PGTW 262100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/260121ZSEP2018//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 02P (TWO) WARNING NR 001    
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   261800Z --- NEAR 10.7S 161.6E
     MOVEMENT PAST SIX HOURS - 110 DEGREES AT 17 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   REPEAT POSIT: 10.7S 161.6E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   270600Z --- 11.2S 162.3E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 195 DEG/ 06 KTS
    ---
   24 HRS, VALID AT:
   271800Z --- 12.3S 162.0E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 250 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   280600Z --- 12.7S 161.0E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 260 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   281800Z --- 13.0S 159.5E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 265 DEG/ 10 KTS
    ---
   72 HRS, VALID AT:
   291800Z --- 13.3S 155.3E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
262100Z POSITION NEAR 10.8S 161.8E.
TROPICAL CYCLONE 02P (TWO), LOCATED APPROXIMATELY 573 NM NORTHWEST 
OF PORT VILA, VANUATU, HAS TRACKED EAST-SOUTHEASTWARD AT 17 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY SHOWS A CONSOLIDATING SYSTEM WITH A LOW LEVEL CIRCULATION 
CENTER COVERED BY SUBSTANTIAL FLARING CONVECTION. THE INITIAL 
POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON A 261648Z SSMIS 
91GHZ IMAGE SHOWING LOW LEVEL CLOUD BANDS WRAPPING IN UNDER THE 
DEEP CONVECTION, AND IS CLOSE TO THE 261800Z PGTW FIX. THE INITIAL 
INTENSITY OF 35 KNOTS IS BASED ON THE DVORAK CURRENT INTENSITY (CI) 
ESTIMATES OF T3.0 (45 KTS) FROM KNES AND NFFN AND THE IMPROVING 
STRUCTURE, AND IS SLIGHTLY ABOVE THE PGTW ESTIMATE OF T2.0 (30 
KTS). ENVIRONMENTAL ANALYSIS SHOWS TY 28W IS LOCATED IN A POCKET OF 
MODERATE (15-20 KT) VERTICAL WIND SHEAR (VWS), WITH SHEAR RAPIDLY 
INCREASING TO THE SOUTH AND WEST, ALONG WITH A DEFINED STRONG 
POLEWARD OUTFLOW. SEA SURFACE TEMPERATURES ARE FAVORABLE, BETWEEN 
28-30 CELSIUS. TC 02P HAS MOVED SOUTHEASTWARD ALONG THE WESTERN 
PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE EAST. TC 02P IS 
FORECAST TO TURN IMMEDIATELY TO THE SOUTH AS THE STR TO THE EAST 
BUILDS IN, THEN TRACK WESTWARD AFTER TAU 24 AS AN EXTENSION OF THE 
STR BUILDS IN TO ITS SOUTH. THE ENVIRONMENT TO THE SOUTHWEST OF TC 
02P IS UNFAVORABLE, WITH HIGH VWS AND COOLER (26-28 CELSIUS) SSTS. 
THEREFORE, TC 02P IS FORECAST TO MARGINALLY INTENSIFY TO 40 KTS BY 
TAU 12, BUT THEN BEGIN WEAKENING AFTER TAU 48 AS IT MOVES INTO A 
MORE UNFAVORABLE ENVIRONMENT, DISSIPATING OVER WATER BY TAU 72. ALL 
NUMERICAL MODEL GUIDANCE DEPICTS THE TURN TO THE SOUTHWEST. IN THE 
NEXT 12 HOURS, HWRF MOVES 02P MORE TO THE SOUTHEAST IN KEEPING WITH 
THE CURRENT MOTION VECTOR, THEN CURVES 02P SHARPLY TO THE WEST. 
EGRR IS THE SOUTHERN OUTLIER, DEPICTING A MORE GRADUAL, SLOWER 
TURN. THE JTWC FORECAST IS PLACED JUST OUTSIDE OF THE MULTI-MODEL 
CONSENSUS. THERE IS FAIR CONFIDENCE IN THE JTWC FORECAST TRACK. 
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 261800Z IS 8 FEET. NEXT WARNINGS 
AT 270300Z, 270900Z, 271500Z AND 272100Z.
2. THIS CANCELS AND SUPERSEDES REF A (WTPS21 PGTW 260130).//
=========================================================================
WTPS31 PGTW 270300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 02P (LIUA) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 02P (LIUA) WARNING NR 002    
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   270000Z --- NEAR 11.2S 162.3E
     MOVEMENT PAST SIX HOURS - 125 DEGREES AT 08 KTS
     POSITION ACCURATE TO WITHIN 020 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   REPEAT POSIT: 11.2S 162.3E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   271200Z --- 12.0S 162.7E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            090 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 215 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   280000Z --- 12.7S 162.2E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            080 NM SOUTHEAST QUADRANT
                            080 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 255 DEG/ 09 KTS
    ---
   36 HRS, VALID AT:
   281200Z --- 13.2S 160.5E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            110 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 270 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   290000Z --- 13.2S 159.1E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
270300Z POSITION NEAR 11.4S 162.4E.
TROPICAL CYCLONE 02P (LIUA), LOCATED APPROXIMATELY 523 NM
NORTHWEST OF PORT VILA, VANUATU, HAS TRACKED SOUTHEASTWARD AT 08
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY SHOWS A SMALL LOW LEVEL CIRCULATION CENETER (LLCC) WITH 
CONVECTION BEING SHEARED TO THE SOUTHWEST. THE INITIAL POSITION IS 
PLACED WITH HIGH CONFIDENCE BASED ON THE EXPOSED LLCC. THE INITIAL 
INTENSITY OF 35 KNOTS IS BELOW MULTIAGENCY DVORAK CURRENT INTENSITY 
(CI) ESTIMATES OF T3.0 (45 KTS), AS SHEAR IS NEGATIVELY IMPACTING 
THE SYSTEM AND A 262301Z ASCAT PASS WITH SIGNIFICANT LAND AND RAIN-
FLAGGED CONTAMINATION SHOWED ONLY ISOLATED 35 KT WIND BARBS, WITH 
POCKETS OF 30 KT WIND BARBS AND MOSTLY 25 KT WIND BARBS SURROUNDING 
THE SYSTEM. ENVIRONMENTAL ANALYSIS SHOWS TC 02P IS LOCATED IN AN 
UNFAVORABLE AREA OF INCREASING (20-25 KTS) VERTICAL WIND SHEAR 
(VWS), ALTHOUGH STRONG POLEWARD OUTFLOW IS HELPING TO MAINTAIN 
CONVECTION. SEA SURFACE TEMPERATURES ARE FAVORABLE, BETWEEN 28-30 
CELSIUS. TC 02P HAS MOVED SOUTHEASTWARD ALONG THE WESTERN PERIPHERY 
OF A SUBTROPICAL RIDGE (STR) TO THE EAST. TC 02P IS FORECAST TO 
TURN IMMEDIATELY TO THE SOUTH AS THE STR TO THE EAST BUILDS IN, 
THEN TRACK WESTWARD AFTER TAU 24 AS AN EXTENSION OF THE STR BUILDS 
IN TO ITS SOUTH. THE ENVIRONMENT IS BECOMING INCREASINGLY 
UNFAVORABLE, WITH VWS INCREASING AND SSTS COOLING ALONG THE TRACK 
OF 02P. TC 02P IS FORECAST TO MARGINALLY INTENSIFY TO 40 KTS BY TAU 
12, BUT THEN BEGIN WEAKENING AFTER TAU 24 AS IT BEGINS MOVING 
WESTWARD INTO A MORE UNFAVORABLE ENVIRONMENT, DISSIPATING OVER 
WATER BY TAU 48. THE VWS WILL CAUSE AN ASYMMETRIC WIND FIELD 
THROUGHOUT THE LIFE OF THE STORM. ALL NUMERICAL MODEL GUIDANCE 
DEPICTS THE TURN TO THE SOUTHWEST, THOUGH THEY VARY IN THE POINT OF 
RECURVATURE, LEADING TO A 165 NM MODEL SPREAD BY TAU 36. THEREFORE, 
THERE IS FAIR CONFIDENCE IN THE JTWC FORECAST TRACK. THE JTWC 
FORECAST IS PLACED JUST OUTSIDE OF THE MULTI-MODEL CONSENSUS IN THE 
INITIAL TAUS AND CLOSE TO THE MULTI-MODEL CONSENSUS IN LATER TAUS. 
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 270000Z IS 9 FEET. NEXT WARNINGS 
AT 270900Z, 271500Z, 272100Z AND 280300Z.//
=========================================================================
WTPS31 PGTW 270900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 02P (LIUA) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 02P (LIUA) WARNING NR 003
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   270600Z --- NEAR 11.8S 162.7E
     MOVEMENT PAST SIX HOURS - 145 DEGREES AT 09 KTS
     POSITION ACCURATE TO WITHIN 050 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
                            075 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   REPEAT POSIT: 11.8S 162.7E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   271800Z --- 12.8S 162.7E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            090 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 250 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   280600Z --- 13.2S 161.7E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 260 DEG/ 06 KTS
    ---
   36 HRS, VALID AT:
   281800Z --- 13.4S 160.4E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            080 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 275 DEG/ 09 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   290600Z --- 13.3S 158.6E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
270900Z POSITION NEAR 12.1S 162.7E.
TROPICAL CYCLONE (TC) 02P (LIUA), LOCATED APPROXIMATELY 480 NM
NORTHWEST OF PORT VILA, VANUATU, HAS TRACKED SOUTHEASTWARD AT 09
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS FLARING CONVECTION IS NOW OBSCURING THE LOW LEVEL
CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON A 270526ZZ 89GHZ MHS MICROWAVE IMAGE WHICH SHOWS
THE DEEPEST CONVECTION IS LOCATED TO THE WEST OF THE LLCC. THE
INITIAL INTENSITY OF 35 KNOTS IS HEDGED BELOW A PGTW DVORAK CURRENT
INTENSITY (CI) ESTIMATE OF T3.0 (45 KNOTS) BASED ON THE 262301Z
METOP-B ASCAT IMAGE WHICH SHOWS A SWATH OF 35 KNOTS. ENVIRONMENTAL
ANALYSIS SHOWS THAT TC 02P IS EXPERIENCING UNFAVORABLE VERTICAL WIND
SHEAR (20 TO 25 KNOTS). POLEWARD OUTFLOW IS STRONG BUT THERE IS NO
EQUATORWARD OUTFLOW. SEA SURFACE TEMPERATURES ARE FAVORABLE, BETWEEN
28 TO 30 DEGREES CELSIUS. TC 02P IS TRACKING SOUTHWARD ALONG THE
WESTERN EDGE OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE EAST. AFTER
TAU 12, TC 02P WILL BEGIN TO TRACK WESTWARD AND ENCOUNTER COOLER SEA
SURFACE TEMPERATURES AND INCREASING VERTICAL WIND SHEAR. THESE
UNFAVORABLE CONDITIONS WILL ALLOW FOR TC 02P TO BEGIN DISSIPATING BY
TAU 36 AND COMPLETELY DISSIPATE BY TAU 48. MODELS AGREE THAT TC 02P
WILL TRACK SOUTHWARD AND THEN TURN WESTWARD. HOWEVER, THERE IS A
LARGE SPREAD IN MODEL GUIDANCE. THE JTWC FORECAST TRACK IS PLACED
NEAR THE MULTI-MODEL CONSENSUS. DUE TO THE LARGE SPREAD IN MODEL
GUIDANCE THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 270600Z IS 9 FEET. NEXT WARNINGS AT
271500Z, 272100Z, 280300Z AND 280900Z.//
=========================================================================
WTPS31 PGTW 271500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 02P (LIUA) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 02P (LIUA) WARNING NR 004
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   271200Z --- NEAR 12.1S 162.6E
     MOVEMENT PAST SIX HOURS - 200 DEGREES AT 03 KTS
     POSITION ACCURATE TO WITHIN 045 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
                            090 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   REPEAT POSIT: 12.1S 162.6E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   280000Z --- 12.6S 162.2E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            090 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 250 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   281200Z --- 13.0S 161.2E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 265 DEG/ 08 KTS
    ---
   36 HRS, VALID AT:
   290000Z --- 13.1S 159.6E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            080 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 275 DEG/ 08 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   291200Z --- 12.9S 157.9E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
271500Z POSITION NEAR 12.2S 162.5E.
TROPICAL CYCLONE (TC) 02P (LIUA), LOCATED APPROXIMATELY 471 NM
NORTHWEST OF PORT VILA, VANUATU, HAS TRACKED SOUTH-SOUTHWESTWARD AT
03 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY SHOWS FLARING CONVECTION CONTINUES TO OBSCURE THE
LOW LEVEL CIRCULATION CENTER (LLCC) ASSOCIATED WITH TC 02P. THE
INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON A 271031Z
89GHZ MHS MICROWAVE IMAGE WHICH SHOWS THE DEEPEST CONVECTION IS STILL
LOCATED TO THE WEST OF THE LLCC. THE INITIAL INTENSITY OF 35 KNOTS IS
HEDGED BELOW A PGTW DVORAK CURRENT INTENSITY (CI) ESTIMATE OF T3.0
(45 KNOTS). TC 02P HAS NOT SHOWN ANY SIGNIFICANT IMPROVEMENT IN
STRUCTURE SINCE THE 260301Z METOP-B ASCAT IMAGE WHICH SHOWED A SWATH
OF 35 KNOT WINDS. ENVIRONMENTAL ANALYSIS SHOWS THAT TC 02P IS
EXPERIENCING MODERATE VERTICAL WIND SHEAR (15 TO 20 KNOTS). POLEWARD
OUTFLOW IS STRONG BUT THERE IS NO EQUATORWARD OUTFLOW. SEA SURFACE
TEMPERATURES ARE FAVORABLE, BETWEEN 28 TO 30 DEGREES CELSIUS. TC 02P
IS TRACKING SOUTHWARD ALONG THE WESTERN EDGE OF A SUBTROPICAL RIDGE
(STR) LOCATED TO THE EAST. THE STR IS BEGINNING TO BUILD WESTWARD AND
WILL ALLOW TC 02P TO ALSO TRACK WESTWARD AND ENCOUNTER COOLER SEA
SURFACE TEMPERATURES AND INCREASING VERTICAL WIND SHEAR. THESE
UNFAVORABLE CONDITIONS WILL ALLOW FOR TC 02P TO BEGIN DISSIPATING BY
TAU 36 AND COMPLETELY DISSIPATE BY TAU 48. DYNAMIC MODELS AGREE THAT
TC 02P WILL TRACK SOUTHWESTWARD AND THEN TURN WESTWARD. HOWEVER,
THERE IS A LARGE SPREAD IN MODEL GUIDANCE. THE JTWC FORECAST TRACK IS
PLACED NEAR THE MULTI-MODEL CONSENSUS. DUE TO THE LARGE SPREAD IN
MODEL GUIDANCE THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 271200Z IS 9 FEET. NEXT WARNINGS
AT 272100Z, 280300Z, 280900Z AND 281500Z.//
=========================================================================
WTPS31 PGTW 272100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 02P (LIUA) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 02P (LIUA) WARNING NR 005
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   271800Z --- NEAR 12.6S 162.2E
     MOVEMENT PAST SIX HOURS - 220 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   REPEAT POSIT: 12.6S 162.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   280600Z --- 13.1S 161.3E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            000 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 260 DEG/ 07 KTS
    ---
   24 HRS, VALID AT:
   281800Z --- 13.4S 159.8E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 010 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 270 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   290600Z --- 13.4S 158.3E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 005 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 280 DEG/ 09 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   291800Z --- 13.1S 156.4E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
272100Z POSITION NEAR 12.7S 162.0E.
TROPICAL CYCLONE 02P (LIUA), LOCATED APPROXIMATELY 467 NM
NORTHWEST OF PORT VILA, VANUATU, HAS TRACKED SOUTHWESTWARD AT 06
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS A BALL OF FLARING CONVECTION CONTINUING TO OBSCURE
THE LOW LEVEL CIRCULATION CENTER (LLCC) ASSOCIATED WITH TC 02P. THE
INITIAL POSITION IS PLACED WITH LOW CONFIDENCE BASED ON INFLOW
UNDER THE CONVECTION IN THE EIR LOOP AND AN EXTRAPOLATED 271636Z
SSMIS 37GHZ IMAGE SHOWING THE DEEPEST CONVECTION DISPLACED SOUTH OF
THE CENTER. THE INITIAL INTENSITY IS PLACED AT 40 KTS, INCREASED 5
KTS OVER THE LAST 6 HOURS, MORE IN LINE WITH MULTIAGENCY DVORAK
CURRENT INTENSITY ESTIMATES OF T3.0 (45 KTS), AND BELOW A 270932Z
SATCON ESTIMATE OF 48 KTS. A SHIP OBSERVATION FROM 40 NM AWAY
RECORDED 38 KT WINDS AND PRESSURE OF 990 MB, WHICH WOULD SUPPORT
WINDS OF 43 KTS. ENVIRONMENTAL ANALYSIS SHOWS THAT TC 02P IS
EXPERIENCING MODERATE VERTICAL WIND SHEAR (15 TO 20 KNOTS), WHICH
IS HINDERING ITS ABILITY TO DEVELOP LONG-TERM, BUT THE LLCC IS
STILL TUCKED UNDER THE CONVECTION AT THIS TIME. POLEWARD OUTFLOW IS
STRONG BUT THERE IS NO EQUATORWARD OUTFLOW. SEA SURFACE
TEMPERATURES ARE FAVORABLE, BETWEEN 28 TO 30 DEGREES CELSIUS. TC
02P IS TRACKING SOUTHWEST ALONG THE WESTERN PERIPHERY OF THE
SUBTROPICAL RIDGE TO THE EAST, AND ABOVE AN EXTENSION OF THE STR TO
ITS SOUTH. THE STR IS BEGINNING TO BUILD WESTWARD AND WILL ALLOW TC
02P TO ALSO TRACK WESTWARD AND ENCOUNTER DRY AIR AND INCREASING
VERTICAL WIND SHEAR, WHICH WILL LEAD TO WEAKENING STARTED AT TAU
24, WITH DISSIPATION EXPECTED BY TAU 48. DYNAMIC MODELS AGREE THAT
TC 02P WILL TRACK SOUTHWESTWARD AND THEN TURN WESTWARD. MODEL
GUIDANCE HAS COME INTO BETTER AGREEMENT NOW THAT THE RECURVE HAS
VERIFIED, WITH 88 NM OF SPREAD AT TAU 36. THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 271800Z IS 13 FEET. NEXT WARNINGS AT 280300Z, 280900Z,
281500Z AND 282100Z.//
=========================================================================
WTPS31 PGTW 280300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 02P (LIUA) WARNING NR 006
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   280000Z --- NEAR 12.2S 161.5E
     MOVEMENT PAST SIX HOURS - 270 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 025 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
                            105 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
   REPEAT POSIT: 12.2S 161.5E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   281200Z --- 12.6S 160.6E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            085 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 260 DEG/ 07 KTS
    ---
   24 HRS, VALID AT:
   290000Z --- 12.9S 159.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            085 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 265 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   291200Z --- 13.0S 157.7E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
280300Z POSITION NEAR 12.3S 161.3E.
TROPICAL CYCLONE 02P (LIUA), LOCATED APPROXIMATELY 514 NM
NORTHWEST OF PORT VILA, VANUATU, HAS TRACKED WESTWARD AT 06 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL VISIBLE IMAGERY
DEPICTS AN ALMOST FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC)
WITH WANING DEEP CONVECTION SHEARED TO THE SOUTHEAST. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PGTW FIX OF
THE EXPOSED LLCC. THE INITIAL INTENSITY IS MAINTAINED AT 40 KNOTS,
BASED ON THE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T3.0 AND THE
MULTI-PLATFORM WIND ANALYSIS ESTIMATE OF 43 KNOTS, HOWEVER DATA-T
VALUES ARE FALLING AND A WEAKENING TREND HAS LIKELY BEGUN. VERTICAL
WIND SHEAR (VWS) IS CURRENTLY MODERATE (15-20 KNOTS) AND EXPECTED
TO INCREASE DUE LARGELY TO THE OUTFLOW OF DEVELOPING TROPICAL
CYCLONE 30W TO THE NORTH.  THIS OUTFLOW IS DIRECTLY OUT OF PHASE
WITH THE LOW LEVEL FLOW. UPPER LEVEL TROUGHING TO THE WEST OF 02P
IS IMPINGING  OUTFLOW, WHICH IS CONSTRAINED TO A POLEWARD CHANNEL
ONLY. LIUA IS TRACKING SOUTHWESTWARD TO WESTWARD UNDER LOW-LEVEL
STEERING FLOW OF A NEAR-EQUATORIAL RIDGE TO THE EAST. THIS STEERING
FLOW WILL BECOME LESS PRONOUNCED AFTER TAU 24, AND THE SYSTEM IS
FORECAST TO DISSIPATE SHORTLY THEREAFTER DUE TO INCREASING VWS.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 280000Z IS 13 FEET. NEXT
WARNINGS AT 280900Z AND 281500Z.//
=========================================================================
WTPS31 PGTW 280900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 02P (LIUA) WARNING NR 007
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   280600Z --- NEAR 12.0S 161.1E
     MOVEMENT PAST SIX HOURS - 295 DEGREES AT 04 KTS
     POSITION ACCURATE TO WITHIN 030 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            075 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   REPEAT POSIT: 12.0S 161.1E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   281800Z --- 12.2S 159.9E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
280900Z POSITION NEAR 12.0S 160.8E.
TROPICAL CYCLONE 02P (LIUA), LOCATED APPROXIMATELY 540 NM
NORTHWEST OF PORT VILA, VANUATU, HAS TRACKED WEST-NORTHWESTWARD
AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) DEPICTS A FULLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC) WITH LIMITED DEEP CONVECTION SHEARED 80NM
TO THE SOUTHEAST. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE PGTW FIX ON THE EXPOSED LLCC IN THE MSI LOOP
AND SUPPORTED BY EXTRAPOLATION FROM A 280531Z 91GHZ SSMIS MICROWAVE
IMAGE. THE INITIAL INTENSITY OF 35 KNOTS IS HEDGED ABOVE PGTW DVORAK
CURRENT INTENSITY ESTIMATE OF T2.0 (30 KTS) BASED ON A GRADUAL
WEAKENING TREND AND THE CONVECTION IN THE SOUTHEAST QUADRANT. UPPER
LEVEL ANALYSIS SHOWS THAT THE SYSTEM HAS WEAK POLEWARD OUTFLOW AND
AN UPPER LEVEL TROUGH IS PREVENTING IMPROVED OUTFLOW. ENVIRONMENTAL
ANALYSIS REVEALS VERTICAL WIND SHEAR (VWS) IS CURRENTLY MODERATE TO
HIGH (20-25 KNOTS) AND FORECAST TO INCREASE DUE LARGELY TO THE
OUTFLOW OF TROPICAL CYCLONE 30W TO THE NORTH. LIUA IS CURRENTLY
TRACKING WEST-NORTHWESTWARD UNDER THE INFLUENCE OF A NEAR-EQUATORIAL
RIDGE TO THE EAST. THIS STEERING FLOW WILL BECOME LESS PRONOUNCED
AFTER TAU 6 AND THE SYSTEM WILL TRACK TO THE WEST-SOUTHWEST AS IT
DISSIPATES DUE TO INCREASING VWS. AVAILABLE DYNAMIC MODEL GUIDANCE
IS IN GOOD AGREEMENT HOWEVER, DUE TO THE WEAK NATURE OF THE STEERING
ENVIRONMENT THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK.
THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON
WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 280600Z
IS 9 FEET.//

Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.


Document: tropical_cyclone_liua_jtwc_advisories.htm
Updated: 17 June 2020
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