WDPN31 PGTW 091500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 03W
/WARNING NR 14//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TROPICAL STORM (TS) 03W (AERE), LOCATED APPROXIMATELY 215 NM
NORTH-NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWARD AT 
09 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE 
IMAGERY SHOWS THE LOW LEVEL CIRCULATION CENTER HAS MOVED JUST OFF 
THE COAST OF NORTHEASTERN LUZON. HOWEVER, THE POSITION IS BASED ON 
THE IR IMAGERY WITH LOW CONFIDENCE. THE IR AND A 091159Z SSMIS 
MICROWAVE IMAGER INDICATE A DECREASE IN DEEP CONVECTION WITHIN THE 
PAST 12 HOURS. THE INITIAL INTENSITY IS BASED ON THE PGTW AND KNES 
DVORAK ESTIMATES OF 35 TO 45 KNOTS. UPPER LEVEL ANALYSIS INDICATES 
THE SYSTEM IS LOCATED IN AN AREA OF DIVERGENCE ALOFT AND GOOD RADIAL 
OUTFLOW, ALTHOUGH LIMITED ON THE NORTHWESTERN PERIPHERY DUE TO AN 
UPPER LEVEL TROUGH ON THAT SIDE. TS 03W CONTINUES TO TRACK ALONG THE 
WESTERN PERIPHERY OF A MID-LEVEL SUBTROPICAL RIDGE.
3. FORECAST REASONING.
   A. THE FORECAST INTENSITY HAS DECREASED SLIGHTLY FROM THE 
PREVIOUS PROGNOSTIC REASONING DUE TO MORE WEAKENING FROM LAND 
INTERACTION THAN PREVIOUSLY FORECAST. 
   B. TS 03W IS EXPECTED TO CONTINUE ROUNDING THE RIDGE AXIS AND 
TRACK JUST SOUTH OF OKINAWA, JAPAN. DUE TO THE UPPER LEVEL TROUGH TO 
THE NORTHWEST CAUSING SUBSIDENCE, TS AERE IS NOT EXPECTED TO RE-
INTENSIFY ONCE IT MOVES FURTHER OFFSHORE OVER WARMER WATERS (27 
DEGREES CELSIUS). IT IS FORECAST TO MAINTAIN INTENSITY THROUGH TAU 
48 WHEN IT WILL ENCOUNTER HIGHER VERTICAL WIND SHEAR ASSOCIATED WITH 
THE MID-LATITUDE WESTERLIES AND COOLER SEA SURFACE TEMPERATURES. TS 
03W IS EXPECTED TO TRANSITION INTO A GALE-FORCE EXTRA-TROPICAL 
SYSTEM BY TAU 72. NUMERICAL MODEL GUIDANCE REMAINS 
TIGHTLY CLUSTERED WITH ALL MODELS CONTINUING TO INDICATE A 
RECURVATURE SCENARIO. THIS FORECAST REMAINS IN GOOD AGREEMENT WITH 
MODEL CONSENSUS ALTHOUGH SLIGHTLY FASTER AND SLIGHTLY RIGHT OF TRACK 
TO ACCOUNT FOR KNOWN MODEL ERRORS DURING THIS TYPE OF SCENARIO.//
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