WDPN31 PGTW 020900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (AERE) WARNING NR 008// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 25.8N 129.5E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 101 NM EAST-SOUTHEAST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 15 KTS SIGNIFICANT WAVE HEIGHT: 18 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH LOW LEVEL CLOUD LINES TIGHTLY WRAPPING THE CENTER. ANIMATED WATER VAPOR IMAGERY AND UPPER-LEVEL ATMOSPHERIC MOTION VECTORS INDICATE A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) IS POSITIONED OVER 05W, INDUCING UNFAVORABLE VERTICAL WIND SHEAR (VWS) AND UPPER-LEVEL SUBSIDENCE. ANIMATED RADAR IMAGERY INDICATES A BROAD LLCC WITH A BULK OF THE DEEP CONVECTION TO THE SOUTHWEST AND A SINGLE SLIGHTLY FRAGMENTED BAND OF CONVECTION WRAPPING AROUND THE NORTHERN SIDE OF THE SYSTEM. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE MSI AND ANIMATED RADAR IMAGERY. THE INITIAL INTENSITY OF 45 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON PGTW DVORAK INTENSITY ESTIMATE AND CIMSS SATCON INDICATING 45 KNOTS WHILE OTHER AGENCY ESTIMATES AS WELL AS CIMSS ADT INDICATING A SLIGHTLY WEAKER SYSTEM. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR) TO THE EAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS RJTD: T2.5 - 35 KTS KNES: T2.5 - 35 KTS CIMSS SATCON: 45 KTS AT 020456Z CIMSS ADT: 34 KTS AT 020540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 5-10 KTS SST: 28-29 CELSIUS OUTFLOW: MODERATE POLEWARD AND EQUATORWARD OTHER FACTORS: TUTT OVER THE LOW-LEVEL CIRCULATION CENTER 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: TS 05W (AERE) IS FORECAST TO CONTINUE TRACKING NORTHWESTWARD UNDER THE STEERING INFLUENCE OF A DEEP-LAYER STR TO THE EAST. CURRENTLY IN A MARGINAL ENVIRONMENT CHARACTERIZED BY WARM SEA SURFACE TEMPERATURES (SST) AND LOW VWS OFFSET BY RESTRICTED UPPER-LEVEL OUTFLOW DUE TO A TUTT AND DRY AIR ENTRAINMENT, 05W IS FORECAST TO REACH ITS PEAK INTENSITY OF 50 KNOTS BY TAU 24. TRACK SPEEDS WILL SLOW AS THE SYSTEM ROUNDS THE STR AXIS THROUGH TAU 48 AND THE SYSTEM BEINGS TO TRACK NORTH-NORTHEASTWARD. BY THIS TIME SSTS WILL HAVE COOLED (26C), UPPER-LEVEL OUTFLOW WILL CONTINUE TO BE MEDIOCRE AND DRY AIR ENTRAINMENT WILL BECOME A SIGNIFICANT FACTOR RESULTING IN CONTINUED WEAKENING. BY TAU 72 THE SYSTEM WILL BE NORTH OF THE STR AXIS AND TRACK SPEEDS WILL HAVE INCREASED AS THE SYSTEM CONTINUES ITS GRADUAL DECLINE IN INTENSITY. BETWEEN TAU 96 AND TAU 120 THE SYSTEM IS FORECAST TO BEGIN IS FINAL DISSIPATION PHASE, WHILE ITS WORTH NOTING IN THE EXTENDED PERIOD SOME MODEL SOLUTIONS SUGGEST, OR TRANSITION INTO A SUBTROPICAL OR EXTRATROPICAL SYSTEM BUT IT IS TOO SOON TO TELL. MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT THROUGH TAU 24 WITH A 75NM SPREAD IN THE SOLUTION. AFTER TAU 24 HWRF AND UKMET SHOW THE SYSTEM CONTINUING STRAIGHT INTO THE YELLOW SEA WHILE THE REMAINDER OF THE GUIDANCE REFLECTS THE JTWC FORECAST OF A RECURVE ALONG THE PERIPHERY OF THE STR TO THE EAST. RELIABLE INTENSITY GUIDANCE IS IN FAIR AGREEMENT THROUGH TAU 24 WITH EVERY MEMBER SHOWING A STEADY TREND OR SLIGHT WEAKENING TREND. AFTER TAU 24 COAMPS-TC (GFS VERSION) AND DECAY-SHIPS SHOW AN INTENSIFICATION TREND WITH COAMPS-TC THE MOST AGGRESSIVE, PEAKING AT 60 KNOTS BY TAU 36 WITH THE REMAINDER OF THE GUIDANCE FOLLOWING THE JTWC INTENSITY FORECAST. FOR THESE REASONS, BOTH THE JTWC INTENSITY AND TRACK FORECAST ARE PLACED WITH MEDIUM CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN