WDPN31 PGTW 260300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W// WARNING NR 06// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM (TS) 10W, LOCATED APPROXIMATELY 150 NM EAST- SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. THE SYSTEM HAS MADE A SIGNIFICANT BEND SOUTH OF THE EXPECTED TRACK DURING THE PAST 12 HOURS DUE TO A STRONG UPPER LEVEL RIDGE TO THE NORTHEAST OF LUZON. SURFACE REPORTS FROM THE CATANDUANES RADAR SITE CONFIRM THAT THE LOW LEVEL CIRCULATION CENTER PASSED NORTH OF THE SITE. RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS SOME INTENSIFICATION IN CONVECTION AROUND THE LOW LEVEL CIRCULATION CENTER (LLCC). A 252043Z SSMIS IMAGE SHOWS CLEAR ORGANIZATION AROUND THE LLCC, BUT THE MAJORITY OF DEEP CONVECTION IS ASSOCIATED WITH LAND INTERACTION ON THE PERIPHERY OF THE SYSTEM. TS 10W IS STILL STRUGGLING TO INTENSIFY AGAINST THE EFFECTS OF STRONG SUBSIDENCE OVER THE NORTHERN SEMICIRCLE. ANIMATED WATER VAPOR IMAGERY REVEALS THE SEVERE DEGREE OF SUPPRESSION TO POLEWARD OUTFLOW. EQUATORWARD OUTFLOW REMAINS WELL ESTABLISHED, HOWEVER, AND NET VERTICAL WIND SHEAR OVER THE SYSTEM REMAINS AT APPROXIMATELY 15 KNOTS. A 252043Z 37 GHZ SSMIS IMAGE CONFIRMS SIGNIFICANTLY BETTER ORGANIZATION IN THE LOW LEVEL BANDING, BUT THE 91 GHZ IMAGE SHOWS THAT THE VAST MAJORITY OF DEEP CONVECTION IS ASSOCIATED WITH LAND INTERACTION. EARLIER ASCAT IMAGERY CONFIRMED BROAD SWATHS OF 25-30 KNOT WINDS EXTENDING OVER 100 NM AWAY FROM THE LLCC. SURFACE REPORTS FROM COASTAL STATIONS IN COASTAL SAMAR AND LUZON SHOW OFF-SHORE WINDS RISING AND PRESSURES FALLING. THE CURRENT INTENSITY ESTIMATE IS BASED ON DVORAK ANALYSES OF 35 KNOTS FROM KNES AND PGTW. B. THE EXTREMELY WARM WATERS OF THE PHILIPPINE SEA AND EXCELLENT EQUATORWARD OUTFLOW WILL COMPENSATE FOR THE SUPPRESSED POLEWARD OUTFLOW AND HELP THE SYSTEM INTENSIFY TO TROPICAL STORM STRENGTH BEFORE LANDFALL. THE SUBTROPICAL RIDGE, CURRENTLY CENTERED OVER THE BONIN ISLANDS, IS RETROGRADING SOUTHEASTWARD AND BEGINNING TO INFLUENCE THE COURSE OF TS 10W TO A GREATER EXTENT. THE STEERING FORCE WILL DRIVE THE SYSTEM ASHORE OVER CENTRAL LUZON NEAR TAU 18. TS 10W WILL WEAKEN SIGNIFICANTLY AS IT TRACKS ACROSS LUZON AND TAKE SOME TIME TO RE-GATHER STRENGTH ONCE IT ENTERS THE SOUTH CHINA SEA. MODEL GUIDANCE HAS STABILIZED AND IS COMING INTO MUCH STRONGER AGREEMENT REGARDING TRACK. ALL CONSENSUS MEMBERS ARE NOW SHOWING A TRACK ACROSS NORTHERN LUZON AND AN EXIT INTO THE SOUTH CHINA SEA SOMEWHERE NEAR OR JUST SOUTH OF THE LINGAYEN GULF. ALTHOUGH SOUTHWESTERLY WINDS REPRESENT THE BIGGEST HAZARD TO SUBIC BAY, THE DEGRADED INTENSITY OF THE SYSTEM IS NOT LIKELY TO RESULT IN A SEVERE WIND EVENT. AS THE STORM MOVES AWAY FROM LUZON, THE SEASONAL ANTICYCLONE OVER EASTERN CHINA WILL BEGIN STEERING THE SYSTEM ON A MORE WESTWARD COURSE, AS WELL AS BRING INCREASED SHEAR TO THE EQUATION. SEA SURFACE TEMPERATURES OVER THE NORTHERN SOUTH CHINA SEA WILL SUPPORT RE-INTENSIFICATION BUT THE INCREASED SHEAR WILL KEEP THE DEVELOPMENT SLOW AND MILD. C. TS 10W WILL STAY SEAWARD OF THE CHINESE COAST, TRACKING OVER NORTHERN HAINAN OR THE LUICHOW PENINSULA AS IT MOVES INTO THE GULF OF TONKIN. ALTHOUGH SEA SURFACE TEMPERATURES WILL REMAIN HIGH THROUGHOUT THE TRACK, THE COMBINED EFFECTS OF EASTERLY SHEAR ALOFT AND LAND INTERACTION IN THE BOUNDARY LEVELS WILL COUPLE TO SLOWLY WEAKEN THE SYSTEM BEFORE LANDFALL. MODEL GUIDANCE IS COMING INTO GOOD AGREEMENT ON TRACK. THE JTWC TRACK FORECAST STAYS WITH CONSENSUS.// NNNN