WTPS21 PGTW 130130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91P)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 200 NM RADIUS OF 18.6S 172.0W 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 27 TO 32 KNOTS. METSAT IMAGERY AT 130100Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 18.6S 172.0W. THE SYSTEM IS
MOVING EASTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 91P) PREVIOUSLY 
LOCATED NEAR 18.6S 173.1W IS NOW LOCATED NEAR 18.6S 172.0W, 
APPROXIMATELY 122 NM WEST-NORTHWEST OF NIUE ISLAND. ANIMATED 
MULTISPECTRAL SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL 
CIRCULATION (LLC) WITH RAPIDLY ORGANIZING DEEP CONVECTION 
OVERHEAD. A 122257Z GMI 89 GHZ MICROWAVE IMAGE REVEALS A COMPACT 
SYSTEM WITH DEEP CONVECTION OFFSET IN THE EASTERN PERIPHERY ALONG 
WITH CONVECTIVE BANDING WRAPPING INTO A WEAK MICROWAVE EYE. THE 
SYSTEM IS CURRENTLY IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY 
NEAR RADIAL OUTFLOW ALOFT, LOW (5-10KT) VWS, AND WARM (28-29C) 
SST. GLOBAL MODELS ARE IN AGREEMENT THAT INVEST 91P WILL CONTINUE 
TO TRACK EAST-SOUTHEASTWARD AS IT GRADUALLY DEVELOPS OVER THE 
NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED 
AT 27 TO 32 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE 
NEAR 1003 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 140130Z.//
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