MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 20W (TALIM) WARNING NR 33// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 20W (TALIM), LOCATED APPROXIMATELY 184 NM SOUTH- SOUTHWEST OF SASEBO, JAPAN, HAS TRACKED NORTHEASTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS DEEPENING CONVECTION ON THE WESTERN SEMI-CIRCLE WRAPPING INTO A LOW LEVEL CIRCULATION CENTER. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON THE ANIMATED RADAR IMAGERY FROM JMA AND EXTRAPOLATION FROM A 161309Z METOP-B ASCAT IMAGE. THE INITIAL INTENSITY OF 55 KNOTS IS HEDGED ON THE LOWER END OF MULTI AGENCY DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM T3.5 TO T4.0 FROM PGTW AND RJTD RESPECTIVELY. THE INTENSITY ESTIMATE IS SUPPORTED BY THE PREVIOUSLY MENTIONED ASCAT IMAGE SHOWING 55 KNOT WIND BARBS AND A SATCON ESTIMATE OF 51 KNOTS. ENVIRONMENTAL ANALYSIS SHOWS THE SYSTEM HAS A STRONG POLEWARD OUTFLOW CHANNEL THAT IS ENHANCED BY THE MID-LATITUDE JET WHILE THE EQUATORWARD OUTFLOW IS BEING SUPPRESSED BY A RIDGE BUILDING TO THE SOUTHEAST. TS 20W IS LOCATED IN AN AREA OF HIGH (20-25 KNOTS) VERTICAL WIND SHEAR AND IS SLOWLY TRACKING THROUGH AN AREA OF WARM (29 CELSIUS) SEA SURFACE TEMPERATURES BUT LOWER OCEAN HEAT CONTENT. THE COMBINATION OF HIGH VERTICAL WIND SHEAR AND LOW OCEAN HEAT CONTENT IS PREVENTING SIGNIFICANT STRENGTHENING OF THE SYSTEM. TS TALIM IS ACCELERATING EAST-NORTHEAST ALONG THE NORTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 20W WILL CONTINUE TO ACCELERATE NORTHEASTWARD AS IT TRACKS ALONG THE NORTHWESTERN EDGE OF THE STR FOR THE DURATION OF THE FORECAST. AS THE SYSTEM TRACKS TOWARDS SOUTHERN JAPAN, A BRIEF PERIOD OF LIMITED INTENSIFICATION PRIOR TO MAKING LANDFALL AS AN APPROACHING MID-LATITUDE TROUGH APPROACHES AND SEA SURFACE TEMPERATURES INCREASE. THE INTENSIFICATION WILL BE LIMITED BY STRONG VERTICAL WIND SHEAR THAT WILL PERSIST UNTIL LANDFALL WHICH WILL OCCUR SHORTLY AFTER TAU 6. INITIAL LANDFALL WILL OCCUR TO THE SOUTH OF SASEBO, THE SYSTEM WILL TRACK NORTHEAST ACROSS SOUTHERN HONSHU, AND OUT INTO THE SEA OF JAPAN PRIOR TO TAU 24. SECONDARY LANDFALL WILL OCCUR OVER SOUTHERN HOKKAIDO AROUND TAU 48. TS TALIM WILL BEGIN TO INTERACT WITH THE APPROACHING MID-LATITUDE TROUGH AND BEGIN EXTRATROPICAL TRANSITION, BECOMING FULLY EXTRATROPICAL BY TAU 72. THE SYSTEM WILL CONTINUE TO TRACK TO THE NORTHEAST THROUGH THE SEA OF OKHOTSK AS A COLD CORE LOW WITH A SUBSTANTIAL GALE FORCE WIND FIELD. DYNAMIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN NNNN