WTPN21 PGTW 101500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 92W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
145 NM EITHER SIDE OF A LINE FROM 15.6N 124.6E TO 20.1N 127.1E
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 101200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 16.0N 124.7E. THE SYSTEM IS MOVING NORTH-NORTHEASTWARD AT 09
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 92W) PREVIOUSLY LOCATED  
NEAR 14.4N 124.9E IS NOW LOCATED NEAR 16.0N 124.7E, APPROXIMATELY  
232 NM EAST-NORTHEAST OF MANILA, PHILIPPINES. ANIMATED MULTISPECTRAL 
SATELLITE IMAGERY (MSI) AND ENHANCED INFRARED SATELLITE IMAGERY (EIR) 
DEPICT A RAPIDLY CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC) 
PARTIALLY EXPOSED BENEATH DEEP FLARING CONVECTION SLIGHTLY SHEARED TO THE 
NORTHWEST. A 101228Z ASCAT METOP-B SCATTEROMETER PARTIAL PASS PAINTS A 
BETTER PICTURE OF THE EASTERN HALF OF 92W WITH 20-25 KNOTS WINDS ON THE 
NORTHERN PERIPHERY FLOWING INTO THE SUSPECTED LLCC, AND 15-20 KNOTS 
FLOWING INTO THAT LLCC FROM THE EASTERN PERIPHERY. UPPER LEVEL ANALYSIS 
REVEALS HIGHLY FAVORABLE CONDITIONS FOR DEVELOPMENT WITH AN ANTICYCLONE 
ALOFT PROVIDING GOOD RADIAL OUTFLOW, LOW (10-15KT) VWS, AND WARM (28-29C) 
SEA SURFACE TEMPERATURES (SST). GLOBAL MODELS ARE IN GOOD CONSENSUS ON 
92W CONTINUING ON A NORTHEASTERLY HEADING AND REMAINING IN FAVORABLE 
CONDITIONS OVER THE NEXT 12-24 HOURS WITH INTENSITY GUIDANCE SHOWING A 
STEADY INTENSIFICATION PROCESS UP TO A LOW END TROPICAL STORM, THEN A 
GRADUAL TAPERING OFF BEYOND TAU 48 AFTER WHICH SHEAR VALUES ARE EXPECTED 
TO DRAMATICALLY RISE. 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 
111500Z.//
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