WTXS21 PGTW 132200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 11.8S 97.4E TO 14.3S 95.2E
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 25 TO 30 KNOTS. METSAT
IMAGERY AT 131800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.1S 97.2E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 07
KNOTS.
2. REMARKS:
THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED NEAR 11.8S 
97.3E IS NOW LOCATED NEAR 12.1S 97.2E, APPROXIMATELY 15 NM EAST OF 
COCOS ISLAND. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 
131541Z MHS 89GHZ MICROWAVE IMAGE REVEAL A CONSOLIDATING SYSTEM WITH 
BUILDING DEEP CONVECTION OVERHEAD AND IMPROVING CONVECTIVE BANDING 
OVER THE WESTERN SEMICIRCLE WRAPPING INTO A TIGHTENING CENTER. 
SURFACE OBSERVATIONS FROM THE COCOS ISLANDS (YPCC) INDICATE 
SOUTHERLY WINDS AT 27KTS WITH SLP 1004MB (3MB 24HR PRESSURE 
DECREASE). A 131425Z METOP-A ASCAT PASS SHOWS A TIGHT LLCC WITH 20-
25 KNOT WRAPPING WINDS AND SMALL AREA OF 30-35 KNOT WINDS TO THE 
SOUTHWEST. INVEST 90S IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT 
WITH GOOD POLEWARD OUTFLOW ALOFT, MODERATE (20-25KTS) VERTICAL WIND 
SHEAR, AND WARM (28-30C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE 
IN GOOD AGREEMENT THAT INVEST 90S WILL TRACK SOUTHWESTWARD, 
INTENSIFYING TO WARNING THRESHOLD WITHIN THE NEXT 24-36 HOURS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 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 
142200Z.//
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