WTIO21 PGTW 200300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91B)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
130 NM EITHER SIDE OF A LINE FROM 10.2N 93.8E TO 16.1N 94.2E
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 23 TO 28 KNOTS. METSAT
IMAGERY AT 200000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 10.5N 93.8E. THE SYSTEM IS MOVING NORTHWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 91B) PREVIOUSLY LOCATED
NEAR 09.9S 93.7E IS NOW LOCATED NEAR 10.5S 93.8E, APPROXIMATELY
401NM SOUTH-SOUTH WEST OF YANGON, MYANMAR. ANIMATED ENHANCED 
INFRARED SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL 
CIRCULATION WITH IMPROVING CONVECTIVE BANDING. A 192234Z SSMIS 91GHZ 
MICROWAVE IMAGE DEPICTS IMPROVED LOW LEVEL BANDING FEATURES AND 
FRAGMENTED CONVECTIVE BANDS ON THE NORTHEAST SIDE EXTENDING TO THE 
SOUTH IN VICINITY OF THE NICOBAR ISLANDS. UPPER-LEVEL ANALYSIS 
INDICATES A FAVORABLE ENVIRONMENT WITH INCREASING POLEWARD OUTFLOW, 
AND LOW (05-10 KNOTS) VERTICAL WIND SHEAR (VWS). SEA SURFACE 
TEMPERATURE VALUES (29-30C) ARE CONDUCIVE FOR FURTHER DEVELOPMENT. 
TRACK GUIDANCE INDICATES A NORTHERLY TRACK OVER THE NEXT 48 HOURS, 
WITH A POSSIBLE LANDFALL ALONG THE WESTERN PORTION OF THE MYANMAR 
COAST. THE BULK OF THE INTENSITY GUIDANCE SUGGETS RELATIVELY STEADY 
BUT SLOW INTENSIFICATION OVER THE NEXT 24 TO 48 HOURS, WHILE THE 
HWRF SUGGESTS MORE RAPID INTENSIFICATION WITH A TRACK MORE OVER 
WATER. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 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 
210300Z.
//
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