MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (KAI-TAK) WARNING NR 10// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 14W (KAI-TAK), LOCATED APPROXIMATELY 190 NM NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) SHOWS THE LOW-LEVEL CIRCULATION CENTER (LLCC) HAS BECOME EMBEDDED WITHIN CENTRAL DENSE OVERCAST (CDO) CONVECTION WITHIN THE PAST SIX HOURS. A 141316Z SSMI 85 GHZ MICROWAVE SATELLITE IMAGE INDICATES THE SYSTEM HAS ALSO BECOME MORE CONSOLIDATED, WITH FRAGMENTED CONCENTRIC DEEP CONVECTION SURROUNDING THE LLCC. THE CURRENT POSITION IS BASED ON POSITION FIXES FROM PGTW AND RJTD AND IS SUPPORTED BY A RECENT 141737Z AMSU-B 89 GHZ IMAGE. UPPER-LEVEL ANALYSIS INDICATES A POINT SOURCE ANTICYCLONE LOCATED JUST TO THE EAST OF TS 14W, AND VERTICAL WIND SHEAR (VWS) HAS DECREASED SLIGHTLY TO 15-20 KNOTS, AS EVIDENT FROM THE CDO OVER THE LLCC. STRONG EQUATORWARD OUTFLOW REMAINS EVIDENT ON WATER VAPOR IMAGERY, AND POLEWARD OUTFLOW HAS BEGUN TO INCREASE SLIGHTLY INTO A NARROW, EAST- WEST ORIENTED TROPICAL UPPER-TROPOSPHERIC TROUGH. THE CURRENT INTENSITY HAS BEEN INCREASED TO 55 KNOTS BASED ON THE IMPROVING DVORAK ESTIMATES FROM PGTW, SATCON INTENSITY ESTIMATES NEAR 60 KNOTS, RECENT MICROWAVE IMAGERY, AND PERSISTENT CENTRAL CONVECTION OBSERVED IN EIR. TS 14W IS BEING STEERED IN A WESTERLY DIRECTION UNDER THE INFLUENCE OF THE DEEP-LAYERED SUBTROPICAL RIDGE (STR) CENTERED FAR TO THE NORTHEAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 14W IS FORECAST TO BEGIN TRACKING MORE WEST-NORTHWESTWARD DURING THE NEXT 12 HOURS UNDER THE INFLUENCE OF THE STR. TS KAI-TAK IS EXPECTED TO INTERACT WITH THE NORTHERN PORTION OF LUZON AND DECREASE SLIGHTLY IN INTENSITY. THE SYSTEM IS THEN EXPECTED TO REGAIN INTENSITY OVER WATER WITH WARM SEA SURFACE TEMPERATURES (> 27 DEGREES CELSIUS) IN A REGION OF LIGHT TO MODERATE (10-20 KNOTS) VWS. ALTHOUGH A SERIES OF WEAK MID-LATITUDE TROUGHS MAY SLIGHTLY WEAKEN THE STR OVER THE NEXT 36 HOURS, THEY ARE NOT EXPECTED TO INFLUENCE A NORTHWARD TRACK. BEYOND TAU 24, TS 14W IS EXPECTED TO CONTINUE INTENSIFYING, REACHING A PEAK OF 70 KNOTS BY TAU 36 AND MAINTAINING INTO TAU 48. AFTER TAU 48, KAI-TAK WILL LIKELY MAINTAIN INTENSITY OR STEADILY WEAKEN AS IT BEGINS INTERACTING WITH LAND AND ENCOUNTERING A LESS FAVORABLE UPPER-LEVEL ENVIRONMENT (> 20 KNOTS VWS). C. BY TAU 72 TS 14W IS EXPECTED TO BE INLAND JUST NORTH OF HONG KONG AND CONTINUE TO WEAKEN UNDER THE INFLUENCE OF FRICTIONAL DRAG AND THE LOSS OF THE OCEAN HEATING. NUMERICAL MODEL GUIDANCE REMAINS IN FAIR AGREEMENT WITH THE EXCEPTION OF JGSM, WHICH IS A LEFT OUTLIER TRACKING THE STORM WELL TO THE WEST OF HONG KONG AND THE MODEL CONSENSUS. WBAR IS THE EASTERNMOST OUTLIER WITH A LANDFALL IN CHINA WELL EAST OF HONG KONG. ALL OTHER NUMERICAL MODELS ARE CLOSE TO THE MODEL CONSENSUS WITH A TRACK OVER NORTHERN LUZON AND LANDFALL NEAR OR JUST TO THE EAST OF HONG KONG. CONFIDENCE IS INCREASING IN THE CURRENT POSITION BASED ON THE AFOREMENTIONED MICROWAVE IMAGERY AND THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK BASED ON ANALYSIS OF THE SYNOPTIC ENVIRONMENT AND NUMERICAL MODELS SHOWING A SIMILAR PICTURE WITH ONLY SLIGHT VARIATIONS IN THE AMOUNT OF WEAKENING DEPICTED FOR THE STR.// NNNN NNNN