WTPN21 PHNC 090300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90E) REISSUED//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/080251ZMAY21//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 12.8N 106.3W TO 15.9N 108.5W
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 15 TO 20 KNOTS. METSAT
IMAGERY AT 090000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 13.3N 106.9W. THE SYSTEM IS MOVING NORTHWESTWARD AT 06
KNOTS.
2. REMARKS: ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS 
WARMING CLOUD TOPS AND SPIRAL BANDS OF MID AND LOW LEVEL CONVECTION 
WRAPPING INTO A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER. 
INVEST 90E IS TRACKING GENERALLY NORTHWESTWARD THOUGH A FAVORABLE 
ENVIRONMENT CHARACTERIZED BY VERY WARM (29-30 CELSIUS) SEA SURFACE 
TEMPERATURES, LOW (5-10 KTS) VERTICAL WIND SHEAR AND MODEST POLEWARD 
OUTFLOW, OFFSET SLIGHTLY BY A LACK OF UPPER LEVEL, EQUATORWARD 
OUTFLOW. NUMERICAL MODEL SOLUTIONS AGREE, HOWEVER, THAT THE 
ENVIRONMENT WILL BECOME LESS FAVORABLE OVER THE NEXT 48-72 HOURS. 
INCREASING VERTICAL WIND SHEAR, COUPLED WITH DRY AIR ENTRAINMENT 
ALONG THE WESTERN PERIPHERY OF THE SYSTEM, WILL HINDER 
INTENSIFICATION DRUING THIS TIME AS INVEST 90E CONTINUES TO SLOWLY 
TRACKS NORTHWESTWAWRD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED 
AT 15 TO 20 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 REMAINS HIGH. THIS 
SUPERSEDES REF A.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 
100300Z.//
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