WDPN31 PGTW 290300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (MALOU) WARNING NR 021// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 30.0N 144.5E INITIAL INTENSITY: 75 KTS GEOGRAPHIC REFERENCE: 212 NM NORTHEAST OF CHICHI JIMA MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 21 KTS SIGNIFICANT WAVE HEIGHT: 36 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES THAT THE TYPHOON IS NOW IN THE EXTRATROPICAL TRANSITION STAGE, WITH THE INNER CORE QUICKLY APPROACHING A SHARPLY-DEFINED COLD FRONT JUST TO THE NORTH. THE COOL, DRY MID-LATITUDE AIR MASS TO THE WEST CAN NOW BE SEEN WRAPPING AROUND THE SOUTHERN SEMICIRCLE, DENOTED BY A DECK OF STRATOCUMULUS IN THE SOUTHWEST QUADRANT OF THE CIRCULATION. THE EYE STRUCTURE HAS COLLAPSED, AND A RAGGED AREA OF MODERATE CONVECTION NOW OBSCURES THE LOW-LEVEL CENTER. A SYNTHETIC APERTURE RADAR (SAR) PASS FROM 282021Z INDICATED THAT MAXIMUM WINDS WERE AROUND 80 KT AT THE TIME, AND THE CURRENT INTENSITY IS SET A LITTLE LOWER AT 75 KT DUE TO THE ONGOING DECAY IN SATELLITE PRESENTATION. INITIAL WIND RADII BASIS: SAR DATA CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE EAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.0 - 65 KTS RJTD: T4.5 - 77 KTS RCTP: T4.0 - 65 KTS CIMSS SATCON: 76 KTS AT 282055Z CIMSS ADT: 69 KTS AT 282040Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE VWS: 30+ KTS SST: 26-27 CELSIUS OUTFLOW: STRONG POLEWARD OTHER FACTORS: DRY, COOL AIR IN WESTERN AND SOUTHERN SEMICIRCLES ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: EXTRATROPICAL TRANSITION IS NOW EXPECTED TO OCCUR MORE QUICKLY, COMPLETING WITHIN 12 TO 24 HOURS. FORECAST DISCUSSION: RAPID WEAKENING IS BEGINNING AS TYPHOON 25W (MALOU) MERGES WITH THE NEARBY FRONTAL BOUNDARY AND TRANSLATES NORTHEASTWARD OVER COOLER WATERS, WHICH WILL ALSO RESULT IN A QUICK TRANSITION TO AN EXTRATROPICAL CYCLONE DURING THE NEXT 12-24 HOURS. DYNAMICAL MODEL GUIDANCE AGREES THAT THE VORTEX WILL LOSE VERTICAL COHERENCE BY THAT TIME AS IT BECOMES BAROCLINIC IN NATURE. THE JTWC FORECAST TERMINATES AT 24 HOURS AS MALOU BECOMES A GALE-FORCE EXTRATROPICAL CYCLONE WELL EAST OF HOKKAIDO. MODEL DISCUSSION: MODEL GUIDANCE REMAINS TIGHTLY CLUSTERED DURING THE FORECAST PERIOD. THE JTWC TRACK FORECAST IS CLOSE TO THE MULTI-MODEL CONSENSUS, AS IS THE INTENSITY FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH INTENSITY 0 - 72 HR: HIGH// NNNN