WDPN31 PGTW 271500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (DOKSURI) WARNING NR 05// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 07W (DOKSURI), LOCATED APPROXIMATELY 395 NM EAST-NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTH- NORTHWESTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY REVEALS THAT THE PREVIOUSLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) TURNED TO THE NORTHWEST AND MOVED BACK UNDER THE CENTRAL DEEP CONVECTION. A 271105Z SSMIS MICROWAVE IMAGE DEPICTS MOSTLY WEAK CONVECTIVE BANDS WRAPPING INTO THE LLCC, WITH A LARGE AREA OF DEEP CONVECTION IN THE NORTHWESTERN QUADRANT. GIVEN THIS STORM’S HISTORY OF MULTIPLE VORTICES, IT IS STILL POSSIBLE THAT THE AREA OF DEEPEST CONVECTION MAY FORM A NEW LLCC AND ABSORB THE ONE CURRENTLY BEING TRACKED. THE INITIAL POSITION IS BASED ON THE AFOREMENTIONED MICROWAVE IMAGE AND A 270902Z WINDSAT PARTIAL PASS WHICH DEPICTS 25-30 KNOT WINDS ON THE EASTERN PERIPHERY. THE INTENSITY IS HELD AT 35 KNOTS BASED ON CURRENT INTENSITY ESTIMATES FROM PGTW AND RJTD. UPPER-LEVEL ANALYSIS INDICATES A FAIR ENVIRONMENT FOR DEVELOPMENT. THE LATEST CIMSS VERTICAL WIND SHEAR (VWS) PRODUCT REVELS THAT THE VWS HAS LESSENED SLIGHTLY, BUT IS STILL A MODERATE 10-15 KNOTS. ANIMATED WATER VAPOR IMAGERY DEPICTS FAIR EQUATORWARD OUTFLOW, WHILE THE POLEWARD OUTFLOW HAS BEEN WANING. THE CIRA AMSU-BASED RADIAL CROSS SECTION INDICATES A SURPRISINGLY STRONG THREE DEGREE WARM ANOMALY OVER THE LLCC. SEA SURFACE TEMPERATURES (SSTS) REMAIN HIGH (29-30 DEGREES CELSIUS). 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING. B. TS 07W IS CURRENTLY STEERING ALONG THE SOUTHWESTERN PERIPHERY OF AN EAST-WEST ORIENTED DEEP SUBTROPICAL RIDGE (STR), WHICH EXTENDS WESTWARD TO TAIWAN. DUE TO THE PREVIOUS TRACK CORRECTION, THE CURRENT FORECAST TAKES THE SYSTEM SLIGHTLY FURTHER NORTH OF LUZON THAN BEFORE, WHICH WILL REDUCE THE UNFAVORABLE LAND INTERACTION. THE MOST RECENT VERTICAL SOUNDING FROM LAOAG, PHILIPPINES SHOWS EASTERLY FLOW THROUGHOUT ALMOST THE ENTIRE COLUMN, WITH THE MEAN STEERING LEVEL FLOW ESTIMATED AT ABOUT 10 KNOTS. THIS FLOW SHOULD PUT THE SYSTEM BACK ON A MORE WEST-NORTHWEST TRACK. GIVEN THE FAIR OUTFLOW, WARM SSTS AND REDUCED LAND INTERACTION, TS 07W IS EXPECTED TO SLIGHTLY INTENSIFY AS IT MOVES THROUGH THE LUZON STRAIGHT. THE INTENSIFICATION WILL BE LIMITED BY THE MODERATE VWS, WHICH IS EXPECTED TO INCREASE AFTER TAU 48. THE FORECAST CALLS FOR A PEAK INTENSITY OF 55 KNOTS AT TAU 48, WITH LANDFALL NEAR HONG KONG PRIOR TO TAU 72. THERE IS GOOD CONFIDENCE IN THIS PORTION OF THE FORECAST DUE TO GENERALLY GOOD AGREEMENT AMONG THE DYNAMICAL MODELS. C. TS 07W IS EXPECTED TO RAPIDLY WEAKEN AFTER MAKING LANDFALL NEAR HONG KONG AROUND TAU 72. THE MODELS HAVE MORE SPREAD BEYOND TAU 72. GFS AND GFDN ARE WESTERN OUTLIERS, BRINGING THE SYSTEM ASHORE CLOSER TO ZHANJIANG. THERE IS SOME SPREAD AMONG THE AVAILABLE SINGLE MODEL ENSEMBLE PRODUCTS WHICH RANGE FROM A STRONGER STR PRODUCING A MORE WESTWARD TRACK, TO A STRONGER TROUGH DEVELOPMENT LEADING TO A TURN TO THE NORTHEAST OVER TAIWAN. GIVEN THE RANGE OF SCENARIOS, THERE IS LOW CONFIDENCE IN THE EXTENDED FORECAST.// NNNN