MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 29W (KAMMURI) WARNING NR 027// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 29W (KAMMURI), LOCATED APPROXIMATELY 285 NM EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. TY KAMMURI HAS RAPIDLY INTENSIFIED 40KTS (65-105KTS) OVER THE PAST 24 HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY REVEALS A WELL DEVELOPED SYSTEM WITH A ROUND EYE. A 020509Z AMSR2 89GHZ IMAGE DEPICTS TIGHT SPIRAL BANDING WRAPPING INTO A MICROWAVE EYE FEATURE. THE EYE FEATURES PRESENT IN ANIMATED AND MICROWAVE IMAGERY LEND HIGH CONFIDENCE TO THE INITIAL POSITION. THE INITIAL INTENSITY OF 105KTS IS BASED ON A PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T5.5 (102KTS). ENVIRONMENTAL ANALYSIS SHOWS THAT TY 29W IS IN A REGION CONDUCIVE FOR DEVELOPMENT, WITH LOW (10- 15KTS) VERTICAL WIND SHEAR (VWS), WARM (27-28C) SEA SURFACE TEMPERATURES AND HIGH OCEAN HEAT CONTENT. TY KAMMURI IS TRACKING WESTWARD ALONG THE SOUTHWESTERN EDGE OF A SUBTROPICAL RIDGE (STR) WHICH IS LOCATED TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE LAST PROGNOSTIC REASONING MESSAGE. B. TY 29W WILL CONTINUE TO TRACK GENERALLY WESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE STR AND INTENSIFY TO 110KTS BEFORE MAKING LANDFALL BY TAU 12 NEAR LEGAZPI, PHILIPPINES. THE SYSTEM WILL THEN BEGIN TO TRAVERSE THE CENTRAL PHILIPPINES WHERE IT WILL DECREASE IN INTENSITY DUE TO THE FRICTIONAL EFFECTS OF LAND. AN APPROACHING SHORTWAVE TROUGH TO THE NORTHWEST WILL TEMPORARILY ERODE THE STR, CAUSING TY 29W TO BEGIN A WEST-NORTHWESTWARD TRACK AS IT MOVES INTO THE SOUTH CHINA SEA BY TAU 30. DYNAMIC MODELS ARE IN TIGHT AGREEMENT ON THE OVERALL WEST-NORTHWESTWARD TRACK LENDING HIGH CONFIDENCE TO THIS PORTION OF THE JTWC FORECAST TRACK. C. BY TAU 72, WINDS FROM A STRONG NORTHEASTERLY SURGE EVENT WILL BEGIN TO STEER TY 29W SOUTH-SOUTHWESTWARD. INCREASING VERTICAL WIND SHEAR DUE TO STRONG WESTERLY FLOW IN THE UPPER LEVELS WILL LEAD TO A STEEP DECREASE IN INTENSITY THROUGH THE REMAINDER OF THE FORECAST PERIOD, WITH THE SYSTEM BEGINNING TO DISSIPATE AT TAU 72 AND COMPLETING DISSIPATION OVER WATER BY TAU 120. DYNAMIC MODELS CONTINUE TO BE IN GOOD AGREEMENT ON THE TRACK, WITH AFUM THE SOLE OUTLIER, LENDING HIGH CONFIDENCE TO THE OVERALL JTWC FORECAST TRACK. NNNN NNNN