WTPN21 PGTW 212230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 16.1N 123.4E TO 17.0N 117.1E
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 211800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 16.1N 123.3E. THE SYSTEM IS MOVING WESTWARD AT 11 KNOTS.
2. REMARKS:THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR 
15.9N 126.8E IS NOW LOCATED NEAR 16.1N 123.3E, APPROXIMATELY 71 NM EAST 
OF CASIGURAN, PHILIPPINES. ANIMATED MULTISPECTRAL SATELLITE IMAGERY 
(MSI) AND A 212053Z GMI 89GHZ MICROWAVE IMAGE DEPICT A COMPACT, 
PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH PERSISTENT 
CONVECTION ALONG THE EASTERN PERIPHERY OF THE CIRCULATION. ENVIRONMENTAL 
ANALYSIS REVEALS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW (10-15 
KNOTS) NORTHERLY VERTICAL WIND SHEAR, STRONG EQUATORWARD OUTFLOW, AND 
VERY WARM (30-31 C) SEA SURFACE TEMPERATURES. THE DEFINED CIRCULATION IS 
EXPECTED TO QUICKLY MAKE LANDFALL ALONG THE EASTERN COAST OF LUZON AND 
EMERGE WITHIN THE SOUTH CHINA SEA. DETERMINISTIC AND ENSEMBLE MODELS ARE 
IN AGREEMENT THAT THE SYSTEM WILL TRACK WESTWARD OVER LUZON AND 
INTENSIFY WITHIN THE SOUTH CHINA SEA AFTER RECOVERING FROM THE IMMINENT 
LANDFALL. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 
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 HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 
222230Z.
//
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