WTPS21 PGTW 120330
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
170 NM EITHER SIDE OF A LINE FROM 12.3S 169.8E TO 16.3S 171.1E
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 20 TO 25 KNOTS. METSAT
IMAGERY AT 120000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.6S 170.1E. THE SYSTEM IS MOVING EASTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 91P) PREVIOUSLY LOCATED 
NEAR 10.9S 170.4E IS NOW LOCATED NEAR 12.6S 170.1E, APPROXIMATELY 
321 NM NORTH-NORTHEAST OF PORT VILA, VANUATU. ANIMATED MULTISPECTRAL 
SATELLITE IMAGERY (MSI) DEPICTS CONVECTIVE BANDS SPIRALING INTO A 
LOW LEVEL CIRCULATION CENTER (LLCC). A PARTIAL 112125Z METOP-B 89GHZ 
SATELLITE IMAGE REVEALS A POCKET OF DEEP CONVECTION TO THE 
SOUTHEASTERN PERIPHERY. INVEST 91P IS IN A FAVORABLE ENVIRONMENT FOR 
DEVELOPMENT WITH RADIAL OUTFLOW, LOW (0-15 KT) VERTICAL WIND SHEAR 
(VWS), AND WARM (29-30C) SEA SURFACE TEMPERATURES (SST). GLOBAL 
MODELS GENERALLY AGREE THAT INVEST 91P WILL REMAIN QUASI-STATIONARY 
OVER THE NEXT 24 HOURS WHILE CONSOLIDATING BEFORE TURNING TO A 
SOUTHEASTERLY TRACK. DURING THIS TRACK, THE SYSTEM WILL LIKELY BEGIN
DIRECT CYCLONE INTERACTION WITH TROPICAL CYCLONE 04P, POSITIONED TO 
THE SOUTHEAST, AND MAY RESULT IN A FUJIWHARA EFFECTS THEREAFTER. 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA 
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 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 
130330Z.//
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