WTPN21 PGTW 011400
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90W)//
RMKS/
1.FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
130 NM EITHER SIDE OF A LINE FROM 22.1N 145.9E TO 23.5N 150.3E
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 KTS. ASCAT-C IMAGERY
AT 011301Z INDICATES THAT A CONSOLIDATING CIRCULATION CENTER IS LOCATED 
NEAR 23.2N 147.9E. THE SYSTEM IS MOVING NORTH-NORTHWESTWARD AT 08
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED
NEAR 21.4N 148.2E IS NOW LOCATED NEAR 23.2N 147.9E, APPROXIMATELY 373 NM 
EAST-SOUTHEAST OF IWO TO. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) 
AND A 010948Z GMI 89 GHZ IMAGE DEPICT A CONSOLIDATING LOW LEVEL 
CIRCULATION CENTER (LLCC) OBSCURED BY DEEP CONVECTION ALONG THE NORTH 
AND EASTERN PERIPHERIES. ENVIRONMENTAL ANALYSIS FOR THE AREA INDICATES 
MARGINALLY FAVORABLE CONDITIONS FOR DEVELOPMENT WITH WARM (29-30 C) SEA 
SURFACE TEMPERATURES AND STRONG POLEWARD OUTFLOW ALOFT, OFFSET BY 
MODERATE (15-20 KTS) SOUTHERLY VERTICAL WIND SHEAR, AS RELATIVELY DRY 
AIR ASSOCIATED WITH A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) CELL TO 
THE WEST-SOUTHWEST OF THE SYSTEM. GLOBAL DETERMINISTIC AND ENSEMBLE 
MODELS ARE IN GOOD AGREEMENT THAT 90W WILL CONTINUE NORTH-NORTHWESTWARD 
WITH GRADUAL DEVELOPMENT OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED 
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KTS. 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 IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 
021400Z.
//
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