WDPN31 PGTW 151500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 24W (KOPPU) WARNING NR 11// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 24W (KOPPU), LOCATED APPROXIMATELY 463 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED IR IMAGERY SHOWS DEEP CONVECTIVE CLOUD BANDING WRAPPING TIGHTLY INTO AN OBSCURED LLCC. THE 151235Z METOP-A SATELLITE IMAGE SHOWS DEEP CONVECTION, SPECIFICALLY ON THE SOUTHWESTERN PORTION OF THE SYSTEM AND INDICATIONS OF TIGHT LOW LEVEL WRAPPING. THE POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE MICROWAVE IMAGREY. ADDITIONALLY, THE INTENSITY HAS BEEN RAISED TO 60 KNOTS BASED ON INTENSITY ESTIMATES FROM ALL AGENCIES. THE UPPER LEVEL ENVIRONMENT REMAINS MARGINALLY-FAVORABLE WITH 20 KNOTS OF IN-PHASE VWS BEING OFFSET BY EASTERLY DIVERGENT OUTFLOW. TS 24W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF THE DEEP-LAYERED STR EXTENSION, WITH THE STR ANCHORED FAR TO THE NORTHEAST. 3. FORECAST REASONING. A. NO CHANGE TO FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS KOPPU WILL CONTINUE TO TRACK WESTWARD THROUGH TAU 72 ALONG THE SOUTHERN PERIPHERY OF THE STEERING STR EXTENSION AND A BUILDING RIDGE EXTENSION APPROACHING FROM THE WEST. A GRADUAL INTENSIFICATION IS EXPECTED AS VWS CONTINUES TO BECOME IN-PHASE WITH THE STORM MOTION IN ADDITION TO INCREASING SSTS ALONG THE SYSTEM’S TRACK. EXPECT A PEAK INTENSITY OF 100 KNOTS BY TAU 48. BEYOND THAT, THE SYSTEM WILL MAKE LANDFALL AND BEGIN DECAYING IN CENTRAL LUZON. C. IN THE EXTENDED FORECAST, TS 24W WILL SLOW AND TURN POLEWARD DUE TO A SLIGHT BREAK IN THE STR TO THE NORTHWEST. ADDITIONALLY, THE TERRAIN OF LUZON WILL CONTINUE TO DECAY THE SYSTEM THOUGH TAU 96 AND TS KOPPU RE-EMERGING IN THE WESTERN EXTENT OF THE PHILIPPINE SEA BY THE END OF THE FORECAST PERIOD AS A STRONG TROPICAL STORM. MODEL GUIDANCE IS FAIRLY TIGHT THROUGH TAU 48, HOWEVER THERE IS A GREAT SPREAD WITH REGARD TO THE SPEED OF THE POLEWARD TURN. AS SUCH, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK, WHICH IS LAID CLOSE TO THE MULTI MODEL CONSENSUS.// NNNN