WPAC: INVEST 97W

[Hayabusa]

97W INVEST 251020 0000 24.5N 126.2E WPAC 15 0

[Hayabusa]

Now low

ABPW10 PGTW 201500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS REISSUED/201500Z-210600ZOCT2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/201352ZOCT2025//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 20OCT25 1200Z, TROPICAL STORM 30W (FENGSHEN) WAS LOCATED
NEAR 18.5N 114.2E, APPROXIMATELY 228 NM SOUTH OF HONG KONG, AND HAD
TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. MAXIMUM
SUSTAINED SURFACE WINDS WERE ESTIMATED AT 45 KNOTS GUSTING TO 55
KNOTS. SEE REF A (WTPN31 PGTW 201500) FOR FURTHER DETAILS.
(2) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 97W) HAS PERSISTED NEAR 24.2N
124.5E, APPROXIMATELY 20 NM SOUTHEAST OF ISHIGAKIJIMA. ENHANCED
INFRARED SATELLITE IMAGERY (EIR) DEPICTS AN AREA OF FLARING
CONVECTION WITH NO DEFINED LOW-LEVEL CIRCULATION CENTER. A PARTIAL
ASCAT 10201213Z PASS REVEALS A WAVE FEATURE PASSING ISHIGAKIJIMA,
WITH THE STRONGEST WINDS OF 25-30 KNOTS ALONG THE NORTHERN PERIPHERY,
ASSOCIATED WITH THE EASTERN EDGE OF A STRONG COLD-SURGE EVENT.
ENVIRONMENTAL ANALYSIS REVEALS MARGINAL CONDITIONS FOR DEVELOPMENT
WITH MODERATE VERTICAL WIND SHEAR (20-25 KNOTS), DIFFLUENT OUTFLOW
ALOFT, AND WARM SEA SURFACE TEMPERATURES (29-30 C). GLOBAL MODELS
DEPICT THE WAVE FEATURE PUSHING WEST AND INTERACTING WITH THE COLD
SURGE FLOW, PULLING GALE-FORCE NORTHERLY WINDS SOUTHWARD ALONG THE
EASTERN SIDE OF TAIWAN AND WRAPPING INTO THE CUSP, EVENTUALLY HELPING
TO CLOSE IT OFF INTO A CIRCULATION CENTER. THE GFS IS THE MOST
AGGRESSIVE IN DEVELOPING THIS SYSTEM, TRACKING SOUTH-EAST OF TAIWAN
OVER THE NEXT 24-36 HOURS. THE OTHER GLOBAL MODELS AND THE GEFS AND
ECENS ENSEMBLES ALSO SHOW THIS WAVE AND SUBSEQUENT INTERACTIONS WITH
THE NORTHEASTERLY SURGE BUT ARE LESS AGGRESSIVE THAN THE GFS. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1009 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.
(2) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: ADDED LOW AREA IN PARA. 1.B.(1)//
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[Hayabusa]

Jma 18z

TROPICAL DEPRESSION 1010 HPA AT 25N 124E SW SLOWLY.

[Hayabusa]

Up to medium

ABPW10 PGTW 220330
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS REISSUED/220330Z-220600ZOCT2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/220152ZOCT2025//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 22OCT25 0000Z, TROPICAL STORM 30W (FENGSHEN) WAS LOCATED
NEAR 17.2N 111.8E, APPROXIMATELY 214 NM EAST-NORTHEAST OF DA NANG,
VIETNAM, AND HAD TRACKED SOUTHWESTWARD AT 01 KNOTS OVER THE PAST SIX
HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 45 KNOTS
GUSTING TO 55 KNOTS. SEE REF A (WTPN31 PGTW 220300) FOR FURTHER DETAILS.
(2) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED NEAR
24.4N 123.4E IS NOW LOCATED NEAR 22.9N 123.1E, APPROXIMATELY 156 NM EAST
OF KAOHSIUNG, TAIWAN. ANIMATED ENHANCED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS A PARTIALLY-EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) TO
THE SOUTHWEST OF A PATCH OF PERSISTENT, FLARING CONVECTION. A 220108
ASCAT METOP-C SHOWS A COMPACT LOW LEVEL CIRCULATION POSITIONED JUST TO
THE EAST OF GALE FORCE WINDS ASSOCIATED WITH A COLD SURGE TO THE WEST
AND EXTENSIVE 15-20 KT WINDS WRAPPING ALONG THE EASTERN PERIPHERY.
ENVIRONMENTAL ANALYSIS INDICATES MARGINAL CONDITIONS FOR DEVELOPMENT
WITH WARM SEA SURFACE TEMPERATURES (29-30 C) AND GOOD EQUATORWARD
OUTFLOW ALOFT OFFSET BY HIGH VERTICAL WIND SHEAR (25-30 KTS). GLOBAL
MODELS DEPICT 97W POTENTIALLY DEVELOPING AS A DISTINCT, BUT SHORT LIVED,
TROPICAL DEPRESSION SEPARATE FROM THE COLD SURGE FLOW OVER THE NEXT TWO
DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN
THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.
(2) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA 1.B.(1) TO MEDIUM.//
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