WDPN32 PGTW 230900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (FRANCISCO) WARNING NR 005// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 21.9N 129.9E INITIAL INTENSITY: 40 KTS GEOGRAPHIC REFERENCE: 299 NM SOUTH-SOUTHEAST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTHWARD AT 11 KTS SIGNIFICANT WAVE HEIGHT: 19 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL STORM (TS) 10W REMAINS EMBEDDED WITHIN THE NORTHEASTERN PERIPHERY OF A LARGE, APPROXIMATELY 400NM DIAMETER LOW PRESSURE AREA, WHICH IS FORECAST TO GRADUALLY DEEPEN AND STRENGTHEN INTO A MONSOON DEPRESSION WITH EXPANSIVE GALE FORCE WINDS OVER THE NEXT 24 TO 48 HOURS. THIS COMPLEX SYNOPTIC PATTERN IS EVIDENT IN THE CIMSS TOTAL PRECIPITABLE WATER (TPW) ANIMATION, WITH MULTIPLE TROPICAL SYSTEMS ROTATING CYCLONICALLY ALONG THE PERIPHERY (10W, 11W). ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS VAST DEEP CONVECTION WRAPPING FROM THE SOUTH AROUND THE NORTHERN PERIPHERY OF TROPICAL STORM (TS) 10W. DRY AIR BOUNDS THE WESTERN PERIPHERY OF THE CIRCULATION, PARTIALLY EXPOSING THE LOW-LEVEL CIRCULATION CENTER. WATER VAPOR IMAGERY REVEALS STRONG POLEWARD AND EQUATORWARD OUTFLOW. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE AFOREMENTIONED ANIMATED MSI PARTIALLY REVEALING THE LLCC. THE INITIAL INTENSITY OF 40 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AGENCY AND OBJECTIVE FIXES LISTED BELOW. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: A COMPLEX STEERING ENVIRONMENT BETWEEN A SUBTROPICAL RIDGE TO THE EAST AND LARGE CYCLONIC FLOW PATTERN AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS RJTD: T2.0 - 30 KTS RCTP: T2.5 - 35 KTS KNES: T2.5 - 35 KTS CIMSS SATCON: 44 KTS AT 230412Z CIMSS ADT: 41 KTS AT 230530Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG POLEWARD AND EQUATORWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: TS 10W HAS TRACKED FARTHER NORTHWARD THAN REPRESENTED IN THE PREVIOUS WARNING, RESULTING IN AN OVERALL FORECAST TRACK SHIFT NORTHWARD. THE CPA TO KADENA AFB HAS DECREASED TO 60NM AS A RESULT. FORECAST DISCUSSION: TS 10W WILL TRACK NORTHWESTWARD FOR THE NEXT 24HOURS AS THE SYSTEM ON THE NORTHERN PERIPHERY OF A LARGE LOW PRESSURE AREA. THE TRACK WILL CURVE WEST-NORTHWESTWARD BETWEEN TAU 24-36 AS TS 10W BEGINS TO DISSIPATE INTO THE LARGER ENHANCED CYCLONIC FLOW. AS THE SYSTEM BECOMES ABSORBED INTO THE DEVELOPING MONSOON DEPRESSION AT THE END OF THE FORECAST, THE RADIUS OF MAXIMUM WINDS IS EXPECTED TO EXPAND TO GREATER THAN 100NM AND LOSE TROPICAL CYCLONE CHARACTERISTICS AS THE WIND FIELD BECOMES BROAD AND THE CIRCULATION CENTER CLEARS. TS 10W WILL INTENSIFY WHILE IN A FAVORABLE ENVIRONMENT OF LOW VERTICAL WIND SHEAR, WARM SEA SURFACE TEMPERATURES, AND STRONG UPPER-LEVEL DIVERGENCE TO A PEAK OF 45KTS DURING THE NEXT 12 HOURS. AN APPROACHING UPPER-LEVEL TROUGH TO THE WEST WILL CREATE AN UNFAVORABLE UPPER-LEVEL ENVIRONMENT BE TAU 36, RESULTING IN WEAKENING AS THE SYSTEM DISSIPATES INTO THE LARGER FLOW. DRY AIR WILL ENTRAIN INTO THE CORE OF THE CIRCULATION AS WELL, FURTHERING DISSIPATION INTO THE ENHANCED FLOW. MODEL DISCUSSION: GIVEN THE CHALLENGING AND COMPLEX SYNOPTIC ENVIRONMENT, THE JTWC TRACK CONFIDENCE IS LOW. THE JTWC MULTI-MODEL CONSENSUS TRACKERS TRACK 10W SLIGHTLY SOUTH COMPARED TO THE MOVEMENT OF TS 10W ON SATELLITE ANALYSIS. THE JTWC FORECAST LIES NORTHWARD OF THE CONSENSUS CLOSELY TO GFS, GEFS, ECMWF, AND ECENS. THIS PREFERENCE FOR THE ECMWF MODELS IS BASED ON THE SUPERIOR PERFORMANCE OF THE MODEL IN THE DEVELOPMENT STAGE AND INITIAL TRACK TO THIS POINT. THE UNCERTAINTY IN THE TRACK LENDS TO THE INTENSITY GUIDANCE AS MODEL SOLUTIONS VARY ON TRACK SPEED AND ULTIMATELY THE INFLUENCE OF THE UPPER-LEVEL TROUGH TO THE WEST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: LOW INTENSITY 0 - 72 HR: LOW// NNNN