WTPN21 PGTW 240800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 94W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN A 
130 NM RADIUS OF 27.8N 134.2E 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 20 TO 25 
KNOTS. METSAT IMAGERY AT 240730Z INDICATES THAT A CIRCULATION CENTER 
IS LOCATED NEAR 27.8N 134.2E. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD 
AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED 
NEAR 27.7N 134.0E IS NOW LOCATED NEAR 27.8N 134.2E, APPROXIMATELY 395 
NM SOUTHEAST OF SASEBO, JAPAN. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY SHOWS A SLOWLY CONSOLIDATING PARTIALLY-EXPOSED, WELL-DEFINED 
LOW-LEVEL CIRCULATION (LLC) WITH INCREASING CORE CONVECTION. A 240432Z 
COWVR COLOR COMPOSITE 34 GHZ MICROWAVE IMAGE REVEALS CONVECTIVE 
BANDING WRAPPING TIGHTLY INTO A DEFINED LOW-LEVEL CIRCULATION CENTER. 
94W IS LOCATED POLEWARD OF A SUBTROPICAL RIDGE AXIS AND EQUATORWARD OF 
A STATIONARY FRONT. UPPER-LEVEL ANALYSIS INDICATES RIDGING ALOFT WITH 
WEAK DIFFLUENCE. THE ENVIRONMENT IS CONDUCIVE FOR FURTHER DEVELOPMENT 
WITH WARM SEA SURFACE TEMPERATURES (27-29C) AND LOW-TO-MODERATE 
VERTICAL WIND SHEAR OF 15-20 KNOTS. HOWEVER, THE CONDITIONS ARE 
CONSIDERED MARGINALLY FAVORABLE DUE TO ITS CLOSE PROXIMITY TO THE 
WESTERLIES AND ASSOCIATED DRY AIR. GLOBAL MODELS INDICATE A GENERALLY 
SLOW, ERRATIC TRACK THROUGH TAU 48 WITHIN A WEAK STEERING ENVIRONMENT. 
AFTER TAU 48, THE SYSTEM IS EXPECTED TO ACCELERATE POLEWARD TOWARD 
CENTRAL JAPAN, WITH GRADUAL TRANSITION TO A SUBTROPICAL CYCLONE AS THE 
SYSTEM TRACKS UNDER STRENGTHENING UPPER-LEVEL SOUTHWESTERLY FLOW. 
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 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 
250800Z.//
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