WDXS31 PGTW 081500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 11S (FREDDY) WARNING NR 010// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 16.0S 113.1E INITIAL INTENSITY: 80 KTS GEOGRAPHIC REFERENCE: 382 NM NORTH OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 08 KTS SIGNIFICANT WAVE HEIGHT: 32 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND RECENT MICROWAVE IMAGERY (080939Z AND 081105Z SSMIS 91GHZ COLOR COMPOSITE MICROWAVE IMAGES) REVEAL A SIGNIFICANT WEAKENING TREND WITH THE LOW-LEVEL CIRCULATION CENTER (LLCC) DECOUPLING FROM AN OBLONG CENTRAL DENSE OVERCAST FEATURE. THE 081107Z SSMIS 37GHZ MICROWAVE IMAGE REVEALS AN ELONGATED, DEFINED LLCC WITH CONVECTIVE BANDING WRAPPING AROUND THE WESTERN AND NORTHERN QUADRANTS, WHICH SUPPORTS THE INITIAL POSITION WITH MEDIUM CONFIDENCE. THE INITIAL INTENSITY OF 80 KTS IS HEDGED BELOW THE SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES BASED ON THE 081300Z ADT AND AIDT ESTIMATES OF 82 AND 79 KNOTS, RESPECTIVELY. RECENT DMN AND OPEN-AIIR ESTIMATES HAVE DECREASED SHARPLY WITH RECENT ESTIMATES RANGING FROM 50 TO 65 KNOTS. ENVIRONMENTAL CONDITIONS HAVE DEGRADED WITH HIGH (25 KNOTS) EASTERLY VERTICAL WIND SHEAR OFFSET BY MODERATE WESTWARD OUTFLOW. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTH OVER WESTERN AUSTRALIA. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.0 - 90 KTS KNES: T5.5 - 102 KTS APRF: T5.0 - 90 KTS CIMSS SATCON: 73 KTS AT 081151Z CIMSS ADT: 87 KTS AT 081130Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 20-25 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE WESTWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 11S IS FORECAST TO TRACK WESTWARD ALONG THE NORTHERN PERIPHERY OF THE STR THROUGH THE FORECAST PERIOD. MODERATE TO HIGH VWS IS EXPECTED TO PERSIST THROUGH TAU 36, WHICH SHOULD LEAD TO A STEADY WEAKENING TREND. AFTER TAU 36, VWS IS FORECAST TO RELAX ALLOWING FOR A REINTENSIFICATION PHASE. MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, WHICH REMAINS SIGNIFICANTLY LEFT OF TRACK, THE BULK OF THE DETERMINISTIC GUIDANCE REMAINS IN GOOD AGREEMENT WITH A 70 TO 105NM SPREAD IN SOLUTIONS FROM TAU 72 TO TAU 120. THE 080600Z ECMWF ENSEMBLE (EPS) IS IN BETTER AGREEMENT WITH THE BULK OF SOLUTIONS SHOWING A WESTWARD TRACK. AFTER TAU 72, EPS INDICATES INCREASING SPREAD IN THE TAU 96 AND TAU 120 FORECAST POSITIONS REFLECTING INCREASING UNCERTAINTY IN THE JTWC FORECAST TRACK. THERE IS SIGNIFICANT UNCERTAINTY IN THE JTWC INTENSITY FORECAST WITH RELIABLE INTENSITY GUIDANCE REVEALING A LARGE SPREAD AFTER TAU 24. HWRF INDICATES A SHARP WEAKENING TREND TO ABOUT 50 KNOTS THEN A SHARP REINTENSIFICATION TO 105 KNOTS BY TAU 84. THE 080600Z COAMPS-TC ENSEMBLE INDICATES A 20 TO 30 PERCENT PROBABILITY OF RAPID INTENSIFICATION OCCURRING IN THE TAU 30 TO TAU 72 TIMEFRAME. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN