WTXS21 PGTW 260630
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/250621Z APR 22//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW 250630)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 160 NM RADIUS OF 14.2S 101.0E 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 28 TO 33 KNOTS. METSAT IMAGERY AT 260000Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 13.2S 100.9E. THE SYSTEM IS
MOVING NORTH-NORTHEASTWARD AT 04 KNOTS.
2. REMARKS: ANIMATED ENHANCED SATELLITE IMAGERY DEPICTS DEEP 
CONVECTION SOUTHEAST OF THE MAIN PARTIALLY EXPOSED LOW LEVEL 
CIRCULATION (LLC). THE MID AND UPPER LEVELS HAVE RECENTLY DECOUPLED 
FROM THE LLC WITH ELONGATION OF THE OVERALL STRUCTURE. RECENT 
SCATTEROMETRY DATA INDICATES WINDS OF UP TO 30 KNOTS IN THE EASTERN 
SEMICIRCLE OF THE LLC. ENVIRONMENTAL ANALYSIS REVEALS MARGINALLY 
FAVORABLE CONDITIONS FOR DEVELOPMENT DEFINED BY ROBUST POLEWARD 
OUTFLOW ALOFT AND WARM (28-29C) SEA SURFACE TEMPERATURES OFFSET BY 
MODERATE VERTICAL WIND SHEAR (VWS) 20-25KTS. GLOBAL MODELS ARE IN 
GOOD AGREEMENT THAT INVEST 98S WILL LIKELY INTENSIFY TO WARNING 
CRITERIA AND MOVE SLIGHTLY NORTHWEST OVER THE NEXT 24-36 HOURS. 
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH. THIS SUPERSEDES REF A.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 
270630Z.
//
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