WTPN21 PHNC 211330
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90E)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 10.9N 137.6W TO 15.7N 141.6W
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 22 TO 28 KNOTS. METSAT
IMAGERY AT 211230Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 11.2N 137.7W. THE SYSTEM IS MOVING NORTHWARD AT 01 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90E) PREVIOUSLY LOCATED 
NEAR 10.7N 137.5W IS NOW LOCATED NEAR 11.2N 137.7W, APPROXIMATELY 1124 
NM EAST-SOUTHEAST OF HILO, HAWAII. ANIMATED ENHANCED INFRARED 
SATELLITE IMAGERY AND A 210256Z SSMIS 91GHZ IMAGERY DEPICT A DEFINED 
CIRCULATION WITH CONVECTIVE BANDING CONSOLIDATING AROUND THE LOW LEVEL 
CIRCULATION CENTER (LLCC). ANALYSIS REVEALS THAT INVEST 90E IS IN A 
MARGINALLY FAVORABLE ENVIRONMENT FOR FURTHER DEVELOPMENT WITH WARM 
(28C) SEA SURFACE TEMPERATURES, GOOD POLEWARD OUTFLOW ALOFT, AND 
MODERATE (15-20 KTS) VERTICAL WIND SHEAR. GLOBAL MODELS ARE IN GOOD 
AGREEMENT THAT 90E WILL CONTINUE TO INTENSIFY AS THE SYSTEM TRACKS 
NORTH-NORTHWESTWARD OVER THE NEXT 36-48 HOURS. MAXIMUM SUSTAINED 
SURFACE WINDS ARE ESTIMATED AT 22 TO 28 KNOTS. MINIMUM SEA LEVEL 
PRESSURE IS ESTIMATED TO BE NEAR 1007 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 
221330Z.
//
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