WDPN32 PGTW 051500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (DANAS) WARNING NR 007// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 20.8N 118.0E INITIAL INTENSITY: 60 KTS GEOGRAPHIC REFERENCE: 230 NM EAST-SOUTHEAST OF HONG KONG MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 03 KTS SIGNIFICANT WAVE HEIGHT: 22 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS PRONOUNCED DEEP CONVECTIVE BANDING SURROUNDING A PERSISTENT CENTRAL DENSE OVERCAST, FULLY OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC) OF TROPICAL STORM (TS) 05W (DANAS). THE INITIAL STORM POSITION IS ASSESSED WITH HIGH CONFIDENCE THROUGH POSITION EXTRAPOLATION FROM A WELL-DEFINED MICROWAVE EYE PRESENT IN A 051008Z GPM GMI 37 GHZ PASS. THE INITIAL INTENSITY ESTIMATE OF 60 KTS IS LAID WITH MEDIUM CONFIDENCE BASED ON THE AGENCY DVORAK ESTIMATES AND OBJECTIVE AIDS LISTED BELOW. ENVIRONMENTAL ANALYSIS INDICATES HIGHLY FAVORABLE CONDITIONS FOR CONTINUED INTENSIFICATION. KEY INDICATORS INCLUDE ROBUST RADIAL UPPER-LEVEL OUTFLOW, LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS), WARM (29-30 C) SEA SURFACE TEMPERATURES (SST), AS WELL AS CONTINUOUSLY COLD (-83 C) CLOUD TOPS. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT WITH A SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH AND A NEAR-EQUATORIAL RIDGE (NER) TO THE SOUTHEAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.5 - 55 KTS RJTD: T2.5 - 35 KTS RCTP: T3.5 - 55 KTS KNES: T4.5 - 77 KTS DEMS: T3.5 - 55 KTS CIMSS SATCON: 56 KTS AT 051200Z CIMSS ADT: 55 KTS AT 051200Z CIMSS AIDT: 54 KTS AT 051200Z CIMSS D-PRINT: 57 KTS AT 051200Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH 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 IS FORECAST TO TRACK GENERALLY NORTHEASTWARD OVER THE NEXT 48 HOURS. A COMPETING STEERING FLOW ENVIRONMENT IS INDUCING A SLOW AND FLUCTUATING TRANSLATIONAL MOTION, AVERAGING APPROXIMATELY 3 KTS, AS THE SYSTEM APPROACHES THE TAIWAN STRAIT. OVER THE NEXT 12-24 HOURS, STRENGTHENING OF THE NER TO THE EAST IS EXPECTED TO BECOME THE DOMINANT STEERING INFLUENCE, GUIDING TS 05W NORTHEASTWARD. BY APPROXIMATELY TAU 48, THE NER IS FORECAST TO WEAKEN AND RETROGRESS SOUTHWARD, WHILE THE SUBTROPICAL RIDGE (STR) TO THE NORTH AMPLIFIES AND EXTENDS EAST-SOUTHEASTWARD, PROMPTING TS 05W TO MAKE A SHARP WESTWARD TURN TOWARD MAINLAND CHINA. RAPID INTENSIFICATION (RI) IS LIKELY WITHIN THE NEXT 24-36 HOURS, SUPPORTED BY DYNAMICAL AND STATISTICAL MODEL GUIDANCE, INCLUDING RI-SPECIFIC AIDS SUCH AS FRIA, RIDE, RIPA, DTOP, AND RICN. THIS INTENSIFICATION IS CONTINGENT ON THE SYSTEM REMAINING OVER WARM WATERS OF THE TAIWAN STRAIT. BETWEEN TAU 48 AND 72, THE SYSTEM IS FORECAST TO MAKE LANDFALL OVER MAINLAND CHINA, LIKELY SOUTH OF WENZHOU, AND BEGIN INTERACTING WITH TERRAIN, INITIATING A PHASE OF RAPID WEAKENING. COMPLETE DISSIPATION OVER LAND IS PROJECTED BY TAU 96. MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE DEMONSTRATES MODERATE CONSENSUS, WITH A CROSS-TRACK SPREAD OF APPROXIMATELY 30 NM BY TAU 36 WHILE THE SYSTEM TRANSITS THE TAIWAN STRAIT, INCREASING TO 60 NM BEYOND THAT POINT. UKMET (EGRI) REMAINS A NOTABLE OUTLIER, FORECASTING A SOUTHERN TAIWAN LANDFALL NEAR TAU 36. BEYOND TAU 48, MODEL SPREAD INCREASES, AND CONFIDENCE IN THE EXACT LANDFALL LOCATION DIMINISHES. INTENSITY GUIDANCE IS BROADLY ALIGNED IN TERMS OF INTENSIFICATION AND SUBSEQUENT WEAKENING TIMELINES, THOUGH VARIANCE IN PEAK INTENSITY ESTIMATES REMAINS NOTABLE AND CURRENTLY RANGING UP TO 40 KTS. THERE IS STRONG AGREEMENT AMONG CONSENSUS MEMBERS REGARDING SYSTEM WEAKENING BELOW WARNING CRITERIA BY OR BEFORE TAU 96. OF NOTE, CURRENT CONSENSUS TRACK, AND THEREFORE JTWC FORECAST, MARGINALLY SHIFTED TOWARDS TAIWAN SINCE LAST FORECAST, INDICATING A POTENTIAL WEAKER IMPACT FROM THE NER. INCREASED INTERACTION OF THE WIND FIELD WITH TAIWANESE MOUNTAIN RANGES WOULD SIGNIFICANTLY DECREASE PEAK INTENSITY ESTIMATES. OVERALL, WHILE TRACK AND INTENSITY GUIDANCE ARE GENERALLY COHERENT, UNCERTAINTIES REMAIN REGARDING LAND INTERACTION TIMING AND ITS EFFECT ON THE INTENSIFICATION RATE. CONSEQUENTLY, THE JTWC INTENSITY FORECAST IS ASSIGNED 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