WDPN31 PGTW 250300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (SAUDEL) WARNING NR 
025//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS. 
   TROPICAL STORM (TS) 19W (SAUDEL), LOCATED APPROXIMATELY 109 NM 
NORTH-NORTHEAST OF DA NANG, VIETNAM, HAS TRACKED WESTWARD AT 10 
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY REVEALS FLARING DEEP CONVECTION DISPLACED TO THE WEST OF AN 
EXPOSED, WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) DUE TO 
PERSISTENT EASTERLY VERTICAL WIND SHEAR (VWS), WHICH SUPPORTS THE 
INITIAL POSITION WITH GOOD CONFIDENCE. A 242151Z SSMIS 91GHZ 
MICROWAVE IMAGE REVEALS A RAGGED LLCC POSITIONED NORTHEAST OF A DEEP 
CONVECTIVE BURST. THE INITIAL INTENSITY IS ASSESSED AT 45 KTS BASED 
ON A PGTW DVORAK CURRENT INTENSITY ESTIMATE OF 3.0 (45 KTS). 
ENVIRONMENTAL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH 
MODERATE (15-20 KTS) VWS, FAIR EQUATORWARD OUTFLOW AND WARM (27-28 
CELSIUS) SST VALUES. TS 19W IS TRACKING WESTWARD ALONG THE SOUTHERN 
PERIPHERY OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE 
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS 19W WILL CONTINUE TO TRACK WESTWARD TO WEST-SOUTHWESTWARD 
THROUGH THE FORECAST PERIOD WITH STEADY WEAKENING THROUGH TAU 12. 
AFTER MAKING LANDFALL NEAR TAU 18, THE SYSTEM WILL RAPIDLY WEAKEN AS 
IT TRANSITS ACROSS MOUNTAINOUS TERRAIN WITH DISSIPATION EXPECTED BY 
TAU 36. NUMERICAL MODEL GUIDANCE REMAINS IN GOOD AGREEMENT, 
THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK WHICH 
LIES NEAR THE MULTI-MODEL CONSENSUS.//
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