WTPN21 PGTW 102030
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
120 NM EITHER SIDE OF A LINE FROM 24.1N 141.1E TO 27.1N 141.4E
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 23 TO 28 KNOTS. METSAT
IMAGERY AT 101800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 24.4N 141.1E. THE SYSTEM IS MOVING NORTH-NORTHWESTWARD AT 14
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY LOCATED NEAR 
23.2N 141.8E IS NOW LOCATED NEAR 24.4N 141.1E, APPROXIMATELY 26 NM 
SOUTH-SOUTHWEST OF IWO TO. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY (EIR) DEPICTS A COMPACT, WELL DEFINED LOW LEVEL CIRCULATION 
CENTER (LLCC) OBSCURED BY PERSISTENT CONVECTION BUILDING OVER THE 
CENTER. A SURFACE OBSERVATION TAKEN FROM IWO TO AT 101800Z SHOWS EAST-
SOUTHEASTERLY WINDS OF 20 KNOTS GUSTING AT 31 KNOTS. A 101637Z AMSR2 GW1 
89GHZ IMAGE REVEALS CONVECTIVE BANDING WRAPPING ALONG THE SOUTHERN 
PERIPHERY OF THE SYSTEM. ENVIRONMENTAL ANALYSIS FOR THE AREA INDICATES A 
FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW TO MODERATE (15-20 KTS) 
VERTICAL WIND SHEAR FROM THE NORTHWEST, WARM SEA SURFACE TEMPERATURES 
(29-30 C) AND MODERATE EASTWARD OUTFLOW. A TROPICAL UPPER TROPOSPHERIC 
TROUGH (TUTT) FURTHER EAST OF THE SYSTEM IS ENHANCING THE EASTWARD 
OUTFLOW CHANNEL OF THE SYSTEM. GLOBAL DETERMINISTIC AND ENSEMBLE MODELS 
ARE IN GOOD AGREEMENT ON A NORTHWARD TRACK WITH MARGINAL INTENSIFICATION 
OVER THE NEXT 24 HOURS, WITH ECENS BEING THE MOST AGGRESSIVE OVERALL.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 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 
112030Z.
//
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