WDPS31 PGTW 110900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 32P (THIRTYTWO) WARNING NR 001// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 9.1S 138.3E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 481 NM EAST-NORTHEAST OF DARWIN, AUSTRALIA MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 04 KTS SIGNIFICANT WAVE HEIGHT: 12 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A COMPACT TROPICAL CYCLONE (TC) 32P WITH FLARING CONVECTION NEAR THE FULLY OBSCURED LOW-LEVEL CIRCULATION CENTER (LLCC). UPPER LEVEL TROUGH TO THE SOUTH IS ASSISTING THE DEVELOPMENT WITH A STRONG POLEWARD OUTFLOW, WHILE PROXIMITY TO LAND TO THE NORTH IS IMPACTING THE CONSOLIDATION OF THE SOMEWHAT ASYMMETRIC WIND FIELD OF TC 32P. THE SPIRAL BANDS OF DEEP CONVECTION ARE STILL RELATIVELY POORLY ORGANIZED AND HAVE WEAKENED SLIGHTLY OVER THE LAST 6 HOURS. ADDITIONAL ENVIRONMENTAL ANALYSIS REVEALS HIGH MOISTURE CONTENT AVAILABLE THROUGHOUT THE ATMOSPHERIC COLUMN, LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS) AND WARM (28-29 C) SEA SURFACE TEMPERATURES (SST). THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE ANIMATED MSI AND AN EXTRAPOLATION OF A CLEARLY IDENTIFIABLE LLCC PRESENT IN A 110155Z GPM GMI 37 GHZ MICROWAVE PASS. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AGENCY DVORAK FIXES AND A 110218Z OCEANSAT-3 PASS SHOWING 35 KTS WINDS PRIMARILY OVER THE SOUTHERN AND WESTERN PORTIONS OF THE CIRCULATION. INITIAL WIND RADII BASIS: 110017Z METOP-B ASCAT PASS CURRENT STEERING MECHANISM: WEAK STEERING ENVIRONMENT, BETWEEN TWO SUBTROPICAL RIDGES (STR) TO THE SOUTHWEST AND SOUTHEAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS KNES: T2.0 - 30 KTS ADRM: T2.5 - 35 KTS CIMSS D-MINT: 36 KTS AT 110357Z CIMSS D-PRINT: 31 KTS AT 110600Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 5-10 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY. FORECAST DISCUSSION: TC 32P IS FORECAST TO SLOW DOWN, WHILE CURRENTLY TRACKING SOUTHEASTWARD BETWEEN TWO SUBTROPICAL RIDGES. THE SYSTEM IS EXPECTED TO MAINTAIN INTENSITY OVER THE NEXT 24 HOURS, HOWEVER CURRENT ENVIRONMENT IS FORECAST TO BECOME LESS FAVORABLE. THE UPPER LEVEL TROUGH TO THE SOUTH WILL PASS, RESULTING IN DRASTICALLY REDUCED DIVERGENCE ALOFT. ADDITIONALLY, VWS IS EXPECTED TO INCREASE, FURTHER HINDERING ANY POTENTIAL INTENSIFICATION AND LEADING TO THE SHALLOWING OF THE CONVECTIVE STRUCTURE OF THE CIRCULATION. PREDOMINANTLY EASTERLY LOW-LEVEL FLOW WILL THEN STEER THE SYSTEM WESTWARD. TC 32P IS FORECAST TO FULLY DISSIPATE BETWEEN TAUS 24 AND 36. MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN FAIR AGREEMENT THROUGHOUT THE FORECAST PERIOD WITH A MAXIMUM OF JUST 35 NM CROSS- TRACK SPREAD. TRACK SPEED GUIDANCE ADDS TO UNCERTAINTY HOWEVER, AS WITNESSED BY THE ALONG-TRACK SPREAD OF 120 NM AT TAU 36. JTWC TRACK FORECAST IS ASSESSED WITH MEDIUM CONFIDENCE AND IS LAID CLOSE TO THE MULTI-MODEL CONSENSUS, BUT LEANING TOWARDS THE GUIDANCE OF ECMWF ENSEMBLE, AS IT APPEARS TO INITIATE BEST WITHIN THE CURRENT ENVIRONMENT. JTWC INTENSITY GUIDANCE IS ASSESSED WITH MEDIUM CONFIDENCE, DUE TO FAIR AGREEMENT AMONG THE CONSENSUS MEMBERS. WHILE DETERMINISTIC GFS, HAFS AND COAMPS-TC INDICATE IMMEDIATE STEADY WEAKENING AND DISSIPATION WITHIN 12-24 HOURS, HWRF AND STATISTICAL- DYNAMICAL MODELS SUGGEST THAT THE SYSTEM WILL MAINTAIN INTENSITY AT OR SLIGHTLY ABOVE WARNING CRITERIA THROUGHOUT THE FORECAST PERIOD, FOLLOWED BY DISSIPATION SHORTLY AFTER. MAJORITY OF THE ECENS AND GEFS ENSEMBLE GUIDANCE MEMBERS ALSO INDICATE WEAKENING BEGINNING WITHIN THE NEXT 24 HOURS. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM// NNNN