WTPN21 PGTW 060330
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 140 NM 
EITHER SIDE OF A LINE FROM 22.5N 137.4E TO 18.3N 135.1E 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 060251Z INDICATES THAT A 
CIRCULATION CENTER IS LOCATED NEAR 22.5N 137.4E. THE SYSTEM IS MOVING 
SOUTHWESTWARD AT 12 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 91W) PREVIOUSLY LOCATED NEAR 
24.4N 139.5E IS NOW LOCATED NEAR 22.5N 137.4E, APPROXIMATELY 255 NM 
WEST-SOUTHWEST OF IWO-TO. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) 
SHOWS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER WITH PERSISTENT 
DEEP CONVECTION OVER THE WESTERN SEMICIRCLE. A 052149Z SSMIS 91GHZ 
MICROWAVE IMAGE SHOWS FORMATIVE CONVECTIVE BANDING BUT WEAK LOW-LEVEL 
STRUCTURE. UPPER-LEVEL ANALYSIS REVEALS A MARGINALLY FAVORABLE 
ENVIRONMENT WITH MODERATE EQUATORWARD OUTFLOW AND LOW TO MODERATE (10-20 
KNOTS) VERTICAL WIND SHEAR. WARM SST VALUES (30-31C) REMAIN FAVORABLE. 
GLOBAL MODELS INDICATE A SOUTHWARD TO SOUTH-SOUTHWESTWARD TRACK OVER THE 
NEXT TWO DAYS WITH A COMPLEX MERGER OCCURRING WITH INVEST 92W AND GRADUAL 
DEVELOPMENT. 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 
070330Z.//
NNNN