WDPN31 PGTW 242100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (SAUDEL) WARNING NR 
024//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS. 
   TROPICAL STORM (TS) 19W (SAUDEL), LOCATED APPROXIMATELY 145 NM 
NORTHEAST OF DA NANG, VIETNAM, HAS TRACKED WESTWARD AT 12 KNOTS OVER 
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY 
REVEALS FLARING DEEP CONVECTION DISPLACED TO THE WEST DUE TO 
PERSISTENT EASTERLY VERTICAL WIND SHEAR (VWS). A 241930Z GMI 89GHZ 
MICROWAVE IMAGE REVEALS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION 
CENTER LOCATED ALONG THE NORTHEAST EDGE OF A DEEP CONVECTIVE BURST, 
WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. THE 
INITIAL INTENSITY REMAINS ASSESSED AT 50 KTS BASED ON RECENT ASCAT 
DATA, HEDGED SLIGHTLY UNDER PGTW/RJTD DVORAK CURRENT INTENSITY 
ESTIMATES OF 3.5 (55 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 24. 
AFTER MAKING LANDFALL NEAR TAU 24, 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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