MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 27W (SAOLA) WARNING NR 37// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 27W (SAOLA), LOCATED APPROXIMATELY 194 NM SOUTH-SOUTHEAST OF SASEBO, JAPAN, HAS TRACKED NORTHEASTWARD AT 22 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED A 30-NM RAGGED EYE. CONVECTION HAS BEGUN TO GET SHEARED POLEWARD; HOWEVER, THE LOW LEVEL STRUCTURE REMAINS INTACT AND WRAPPED EVEN TIGHTER INTO THE CENTER. THE INITIAL POSITION IS BASED ON THE EYE FEATURE AND ON A RADAR COMPOSITE LOOP FROM JMA WITH HIGH CONFIDENCE. THE INITIAL INTENSITY IS HEDGED ON THE HIGHER END OF AGENCY DVORAK ESTIMATES TO REFLECT THE TIGHTER WRAP. UPPER LEVEL ANALYSIS INDICATES TY 27W IS NOW IN AN AREA OF STRONG (25-30 KNOT) VERTICAL WIND SHEAR (VWS); HOWEVER, ITS STORM MOTION THAT IS IN PHASE WITH THE UPPER LEVEL WIND FLOW AND THE STRONG POLEWARD AND EQUATORWARD OUTFLOW ARE OFFSETTING THE VWS. ON THE NEGATIVE SIDE, THE SYSTEM IS NOW APPROACHING THE COLD BAROCLINIC ZONE, AS EVIDENCED BY AN ENTRAINMENT OF COLD AIR STRATOCUMULUS LINES FROM THE NORTHWEST ON THE EIR LOOP. THE CYCLONE IS ACCELERATING NORTHEASTWARD ON THE NORTHWEST SIDE OF A DEEP-LAYERED SUBTROPICAL RIDGE TO THE SOUTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY SAOLA WILL CONTINUE ACCELERATING NORTHEASTWARD, SKIRTING ALONG THE SOUTHERN COAST OF JAPAN. THE ENVIRONMENT WILL NOW HAVE AN OVERALL NEGATIVE IMPACT ON THE SYSTEM AND CAUSE A GRADUAL TO RAPID WEAKENING TREND. BY TAU 12, AS THE SYSTEM GETS EMBEDDED DEEPER IN THE BAROCLINIC ZONE, TY 27W WILL BEGIN EXTRA-TROPICAL TRANSITION AND BECOME A STRONG GALE-FORCE COLD CORE LOW WITH AN EXPANSIVE WIND FIELD BY TAU 24. AVAILABLE DYNAMIC MODEL GUIDANCE IS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST.// NNNN NNNN