WDXS31 PGTW 071500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 11S (FREDDY) WARNING NR 006// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 14.6S 116.1E INITIAL INTENSITY: 90 KTS GEOGRAPHIC REFERENCE: 476 NM NORTH-NORTHEAST OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 29 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL CYCLONE (TC) 11S HAS CONTINUED TO RAPIDLY INTENSIFY (RI), BRIEFLY FLIRTING WITH AN EYE, AND HAS INTENSIFIED 45 KNOTS OVER THE PAST DAY. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS SPIRAL BANDING WRAPPING INTO A SYMMETRIC, COMPACT CORE. A 071121Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS A SMALL MICROWAVE EYE FEATURE, WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. ENVIRONMENTAL CONDITIONS REMAIN HIGHLY FAVORABLE SUPPORTING THE RI PHASE. THE INITIAL INTENSITY OF 90 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE KNES DVORAK ESTIMATE AND RECENT ADT ESTIMATES RANGING FROM 87 TO 90 KNOTS. THE MOST RECENT AIDT ESTIMATE AS WELL AS THE DMN AND OPEN-AIIR ESTIMATES REMAIN SLIGHTLY LOWER AT 80-83 KNOTS. A 071025Z SMAP IMAGE SHOWS MAXIMUM WINDS (1-MINUTE AVERAGE) OF 72 KNOTS BUT IS LIKELY NOT RESOLVING THE COMPACT INNER CORE OF THE SYSTEM. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTH AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.5 - 77 KTS KNES: T5.0 - 90 KTS APRF: T4.5 - 77 KTS CIMSS ADT: 87 KTS AT 071130Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 11S IS EXPECTED TO TRACK GENERALLY WESTWARD ALONG THE NORTHERN PERIPHERY OF THE STR THROUGH THE FORECAST PERIOD. A SERIES OF FAST-MOVING MIDLATITUDE SHORTWAVE TROUGHS ARE EXPECTED TO PROPAGATE TO THE SOUTH BUT WILL NOT SIGNIFICANTLY IMPACT OR WEAKEN THE STR UNTIL AFTER TAU 120 WHEN A MAJOR SHORTWAVE TROUGH APPROACHES AND DEEPENS TO THE SOUTHWEST. TC 11S WILL PEAK AT 110 KNOTS BY TAU 24 AND WILL THEN WEAKEN BRIEFLY BEFORE REINTENSIFYING NEAR TAU 72. THIS SHORT DURATION WEAKENING PHASE IS ASSOCIATED WITH A PERIOD OF INCREASING UPPER-LEVEL EASTERLIES AND HIGHER VERTICAL WIND SHEAR AS WELL AS DRY AIR ENTRAINMENT AS INDICATED IN GFS AND ALL THE RELIABLE INTENSITY GUIDANCE. MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, THE DETERMINISTIC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH TAU 72 WITH A 50NM SPREAD IN SOLUTIONS AT TAU 72. PROBABILISTIC GUIDANCE SUPPORTS A GENERALLY WESTWARD TRACK BUT SHOWS A LARGER SPREAD OF SOLUTIONS. AFTER TAU 72, BOTH THE DETERMINISTIC AND PROBABILISTIC GUIDANCE DIVERGES REFLECTING INCREASING UNCERTAINTY IN THE JTWC FORECAST TRACK. THE 070000Z COAMPS-TC ENSEMBLE, WHICH EXCELS AT IDENTIFYING RI, INDICATES 60 TO 80 PERCENT PROBABILITIES SUPPORTING SUSTAINED INTENSIFICATION OVER THE NEXT 24 HOURS. ALTHOUGH THE COAMPS-TC RI PROBABILITIES DECREASE FROM TAU 24 TO TAU 60, THERE IS AN INCREASE TO 20 TO 30 PERCENT PROBABILITY IN THE DAY 3 TO DAY 4 TIMEFRAME, WHICH SUPPORTS THE CURRENT JTWC INTENSITY FORECAST PHILOSOPHY. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN