WTPN21 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 93W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 11.2N 165.5E TO 16.4N 157.6E
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 110600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 11.3N 165.1E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 22
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY LOCATED NEAR 
11.3N 165.1E IS NOW LOCATED 11.3N 165.1E APPROXIMATELY 121 NM 
NORTHWEST OF KWAJALEIN. ANIMATED ENHANCED INFRARED (EIR) SATELLITE 
IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH 
DEEP CONVECTION BUILDING IN THE NORTHWESTERN PERIPHERY AND NEAR THE 
CENTER OF THE LLC. EARLIER ASCAT DATA SUGGESTED THAT THE CENTER IS MORE 
OF A CUSP FEATURE THAN A TRUE CIRCULATION CENTER, HOWEVER THE LATEST 
ANIMATED SATELLITE IMAGERY SHOWS SIGNS OF A CIRCULATION CENTER EMERGING. 
ENVIRONMENTAL ANALYSIS INDICATES THAT 93W IS IN A FAVORABLE ENVIRONMENT 
FOR FURTHER DEVELOPMENT WITH LOW (LESS THAN 15 KNOTS) VERTICAL WIND 
SHEAR, VERY WARM (30-31C) SEA SURFACE TEMPERATURES, AND GOOD POLEWARD 
OUTFLOW ALOFT. BOTH THE GFS AND ECMWF ENSEMBLE MODELS ARE IN GOOD 
AGREEMENT WITH ANOTHER ON THE CONSOLIDATION OF INVEST 93W AND GENERAL 
WEST-NORTHWESTWARD TRACK OVER THE NEXT 24 HOURS. DETERMINISTIC MODELS ARE 
ALSO IN GOOD AGREEMENT THAT 93W WILL CONTINUE TO INTENSIFY OVER THE NEXT 
12-24 HOURS AS WELL. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 
TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 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 
090900Z.//
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