WTPN21 PHNC 021930
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99E)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 12.3N 101.8W TO 13.7N 104.8W
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 021800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.4N 102.0W. THE SYSTEM IS MOVING WESTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 99E) PREVIOUSLY 
LOCATED NEAR 12.3N 101.4W IS NOW LOCATED NEAR 12.4N 102.0W,
APPROXIMATELY 1468 NM SOUTHEAST OF SAN DIEGO, CALIFORNIA. ANIMATED 
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS PERSISTENT DEEP CONVECTION 
BUILDING OVER THE CENTER OF THE CIRCULATION. ENVIRONMENTAL ANALYSIS 
SHOWS FAVORABLE CONDITIONS FOR THE DEVELOPMENT OF 99E WITH LOW VERTICAL 
WIND SHEAR (5-10 KTS), GOOD EQUATORWARD OUTFLOW, AND WARM SEA SURFACE 
TEMPERATURES (27-30 C). DETERMINISTIC AND ENSEMBLE MODELS ARE IN 
AGREEMENT ON A STEADY DEVELOPMENT OVER THE NEXT 48 HOURS AND ON A 
SIMILAR WEST-NORTHWESTWARD TRACK. MAXIMUM SUSTAINED SURFACE WINDS ARE 
ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO 
BE NEAR 1009 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 
031930Z.//
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