MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W (TALIM) WARNING NR 13// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 06W (TALIM), LOCATED APPROXIMATELY 20 NM NORTHWEST OF TAIPEI, TAIWAN, HAS TRACKED NORTHEASTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY AND A 201716Z AMSU MICROWAVE IMAGE INDICATE SIGNIFICANTLY WEAKENED DEEP CONVECTION AND ORGANIZATION DUE TO LAND INTERACTION WITH TAIWAN AND INCREASED VERTICAL WIND SHEAR. THE TAIWAN RADAR NO LONGER DEPICTS AN ORGANIZED LOW LEVEL CIRCULATION CENTER (LLCC). OBSERVATIONS FROM TAIPEI INDICATE LIGHT WESTERLY WINDS. THE INITIAL POSITION WAS BASED ON THE AMSU MICROWAVE IMAGE WITH VERY LOW CONFIDENCE. THE INTENSITY WAS BASED ON THE RJTD DVORAK ESTIMATE OF 30 TO 35 KNOTS WITH UNCERTAINTY DUE TO THE LACK OF DEEP CONVECTION OVER THE LLCC. UPPER LEVEL ANALYSIS AND A SOUNDING FROM TAIPEI INDICATE THE SYSTEM IS LOCATED IN AN AREA OF 35 TO 45 KNOTS OF VERTICAL WIND SHEAR ASSOCIATED WITH THE MEI-YU FRONT. THE SYSTEM IS CURRENTLY TRACKING ALONG THE NORTHWEST PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TD 06W IS EXPECTED TO CONTINUE TRACKING ALONG THE NORTHWEST PERIPHERY OF THE STR. ALONG TRACK SEA SURFACE TEMPERATURES WILL DECREASE BELOW 26 DEGREES CELSIUS AND VERTICAL WIND SHEAR WILL INCREASE AS THE SYSTEM INTERACTS WITH THE MEI-YU FRONT, CURRENTLY EXTENDING TO KYUSHU, JAPAN. AN UPPER-AIR SOUNDING FROM KAGOSHIMA, JAPAN INDICATES THE JET IS DIPPING DOWN OVER THIS REGION. TD 06W IS EXPECTED TO TRANSITION INTO AN EXTRA-TROPICAL LOW JUST BEFORE REACHING KYUSHU, AROUND TAU 24. THE TIMING OF EXTRA-TROPICAL TRANSITION IS FORECAST TO OCCUR SOONER THAN PREVIOUSLY FORECAST BASED ON THE ANALYSIS OF THE BAROCLINC ZONE. THERE IS GOOD CONFIDENCE IN THE TRACK FORECAST DUE TO THE TIGHT MODEL PACKING AND A STRONG STEERING STR. HOWEVER, THERE IS UNCERTAINTY IN THE INTENSITY FORECAST AND WHETHER OR NOT THE SYSTEM WILL SURVIVE ABOVE WARNING CRITERIA (25 KNOTS) BEFORE COMPLETING EXTRA-TROPICAL TRANSITION. REGARDLESS, TD 06W WILL REMAIN A WEAK SYSTEM AS IT CONTINUES TO INTERACT WITH THE BAROCLINIC ZONE WITH HIGH VERTICAL WIND SHEAR.// NNNN NNNN