MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (HALONG) WARNING NR 16// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 11W (HALONG), LOCATED APPROXIMATELY 313 NM NORTH OF YAP, FSM, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL AND WATER VAPOR SATELLITE IMAGERY SHOWS THE SYSTEM CONTINUES TO BE AFFECTED BY STRONG (30-40 KNOT) NORTHERLY VERTICAL WIND SHEAR (VWS), INDUCING A SLIGHTLY EXPOSED LOW LEVEL CIRCULATION CENTER. THE INITIAL POSITION IS BASED ON THE ABOVE ANIMATION WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS A CONSENSUS OF DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS WELL SOUTH OF THE RIDGE AXIS IN AN AREA OF HIGH VWS. HOWEVER, THESE SAME WINDS ARE PROVIDING STRONG EQUATORWARD OUTFLOW FOR THE SYSTEM. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A WEAK SUBTROPICAL RIDGE (STR) LOCATED IN THE EASTERN PHILIPPINE SEA. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 11W IS EXPECTED TO CONTINUE ITS WEST TO WEST-NORTHWEST TRACK AS IT REMAINS UNDER THE INFLUENCE OF THE STR TO THE NORTH OVER THE NEXT 24-36 HOURS. BETWEEN TAU 36 AND 72, EXPECT TS HALONG TO ROUND THE SOUTHWEST EXTENSION OF THE STR AND SLOWLY TURN MORE NORTHWESTWARD. AS THE VWS WILL WEAKEN AND ALLOW FOR A MORE FAVORABLE UPPER-LEVEL ENVIRONMENT, 11W WILL INTENSIFY AT A FASTER RATE BETWEEN TAU 36 AND 72, REACHING A PEAK INTENSITY OF 85 KNOTS BY TAU 72. C. TS HALONG WILL GENERALLY TRACK NORTHWESTWARD THROUGH THE REMAINDER OF THE FORECAST PERIOD. AFTER TAU 120, EXPECT THE MONSOON DEPRESSION CURRENTLY AFFECTING THE EAST CHINA SEA TO BE ABSORBED IN AN UPPER LEVEL TROUGH AND MODIFY THE STR WHICH WILL BE OVER MAINLAND JAPAN. NUMERIC MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 72, WITH SOME DIVERGENCE IN THE MODELS IN THE LATER TAUS WITH REGARD TO THE LEADING STEERING ENVIRONMENT. GFS AND ECMWF AGREE THAT THE RIDGE DEVELOPING TO THE EAST OF JAPAN WILL BE MAIN FACTOR, LENDING TO A RECURVE SCENARIO OVER SOUTHERN JAPAN, WHILE NAVGEM HAS THE HIGH OVER MAINLAND CHINA AFFECTING THE STORMS TRACK, BRINGING THE SYSTEM INTO THE YELLOW SEA. THIS LENDS AN OVERALL LOW CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN NNNN