WDPN32 PGTW 021500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (SAOLA) WARNING NR 040// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 21.9N 110.5E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 262 NM EAST-NORTHEAST OF HANOI, VIETNAM MOVEMENT PAST 6 HOURS: WESTWARD AT 13 KTS SIGNIFICANT WAVE HEIGHT: XX FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL STORM 09W (SAOLA) CONTINUES TO TRACK INLAND OVER SOUTHERN CHINA, WHILE STEADILY AND RAPIDLY WEAKENING. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY CONTINUES TO SHOW THE UPPER-LEVEL CIRCULATION CENTER ASSOCIATED WITH TS 09W MOVING WESTWARD. MEANWHILE, A 021010Z SSMIS MICROWAVE IMAGER PASS SHOWS A REMNANT EYE FEATURE ON THE SOUTHERN SIDE OF A LARGE MASS OF DEEP CONVECTION. THIS DEPICTION MATCHES UP WITH THE ANIMATED RADAR DATA WHICH DEPICTS THE LOW-LEVEL CIRCULATION CENTER JUST A SHADE FURTHER SOUTH. A MELD OF THE MICROWAVE AND RADAR DATA PROVIDES MEDIUM CONFIDENCE TO THE INITIAL POSITION. THE INITIAL INTENSITY IS ASSESSED WITH LOW CONFIDENCE. DUE TO A DEARTH OF INTENSITY ESTIMATES FOR A SYSTEM OVER LAND. THE ONLY INTENSITY ESTIMATES AVAILABLE INCLUDE THE DPRINT AND DMINT, BOTH OF WHICH WERE 40 KNOTS AT 1200Z. SOUTHEASTERLY SHEAR REMAINS RELATIVELY HIGH, WHICH COMBINED WITH THE NEGATIVE IMPACT OF TERRAIN INTERACTION, MORE THAN OFFSETS ANY POSITIVE SUPPORT PROVIDED BY THE ROBUST POLEWARD OUTFLOW CHANNEL. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHEASTERN PERIPHERY OF A LOW TO MID-LEVEL RIDGE OVER CENTRAL CHINA. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: NO CURRENT ESTIMATE RCTP: T4.0 - 65 KTS FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE VWS: 15-20 KTS SST: OVER LAND OUTFLOW: STRONG POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: DESPITE A RECENT JOG A BIT FURTHER NORTH THAN ANTICIPATED, TS 09W IS STILL EXPECTED TO TURN MORE WEST AND ULTIMATELY SOUTHWEST OVER THE NEXT 12 TO 24 HOURS, EMERGING INTO THE GULF OF TONKIN AROUND TAU 12. THE SYSTEM WILL SLOWLY DRIFT SOUTHWESTWARD BEFORE ROUNDING THE WESTERN SIDE OF HAINAN ISLAND BY THE END OF THE FORECAST PERIOD. THE SYSTEM IS WEAKENING AT A FASTER PACE THAN ORIGINALLY ANTICIPATED BUT IS STILL LIKELY TO EMERGE INTO THE GULF OF TONKIN AS A WEAK TROPICAL STORM. HOWEVER, WHILE SSTS ARE VERY WARM IN THE GULF, THE LACK OF MUCH, OR ANY, UPPER-LEVEL OUTFLOW AND THE ENVELOPMENT OF THE CIRCULATION IN DRY AIR MEANS THAT IT WILL NOT BE LONG FOR THIS WORLD. THE SYSTEM STEADILY WEAKENS THROUGH THE FORECAST PERIOD, BEFORE DISSIPATING AS A TROPICAL CYCLONE OFF THE SOUTHWEST COAST OF HAINAN BY TAU 72. MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS STILL SOMEWHAT SPLIT BETWEEN THE EUROPEAN MODELS AND THE US MODELS PLUS THE ENSEMBLE MEANS. THE ECMWF AND EGRR TRACKERS INSIST ON TAKING THE SYSTEM STRAIT SOUTHWEST TO A VIETNAM LANDFALL AROUND TAU 72, AND QUICK DISSIPATION THEREAFTER. THE REMAINDER OF THE CONSENSUS MEMBERS INCLUDING THE GFS AND THE GEFS AND ECENS ENSEMBLE MEANS, TRACK THE SYSTEM CLOSER TO HAINAN ON A BROADLY CURVING TRACK BEFORE SHIFTING TO A QUASI-STATIONARY MOTION AROUND TAU 72 AS THE SYSTEM DISSIPATES. THE JTWC FORECAST IS CONSISTENT WITH THE BULK OF THE MODEL GUIDANCE WITH MEDIUM CONFIDENCE. INTENSITY GUIDANCE IS IN GOOD AGREEMENT THAT THE SYSTEM WILL WEAKEN TO TAU 24, THEN HOLD STEADY FOR A BRIEF PERIOD, BEFORE DISSIPATING BY TAU 72. HOWEVER, UNCERTAINTY IN THE INTENSITY OF THE SYSTEM AS IT MOVES BACK OVER WATER GENERATES MEDIUM CONFIDENCE IN THE JTWC FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM// NNNN