WDPN31 PGTW 160900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (LAN) WARNING NR 035// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 39.5N 135.9E INITIAL INTENSITY: 40 KTS GEOGRAPHIC REFERENCE: 250 NM WEST OF MISAWA, JAPAN MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 13 KTS SIGNIFICANT WAVE HEIGHT: 22 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH UPPER LEVEL CONVECTION BEING RAPIDLY VENTED POLEWARD. A 160331Z AMSR2 89GHZ MICROWAVE IMAGE SHOWS A WELL DEFINED LOW LEVEL CIRCULATION WITH A BROAD AND SLIGHTLY ELONGATED CENTER. A PARTIAL 160130Z ASCAT-C SCATTEROMETERY PASS INDICATED THE WIND FIELD TO THE EAST OF THE LLCC IS BOTH SMALLER AND WEAKER THAN JUST A FEW HOURS BEFORE, SHOWING A MAX INTENSITY OF 40KTS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON MSI AND AMSR2 IMAGERY. THE INITIAL INTENSITY OF 40 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON EARLIER SCATTEROMETRY DATA ECHOING CURRENT CIMMS AIDT, DPRINT AND AGENCY DVORAK INTENSITY ESTIMATES OF 38-41 KTS. INITIAL WIND RADII BASIS: PARTIAL SCATTEROMETER DATA CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) TO THE EAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS RJTD: T2.0 - 30 KTS RCTP: T2.5 - 35 KTS CIMSS SATCON: 39 KTS AT 160333Z CIMSS ADT: 34 KTS AT 160220Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY UNFAVORABLE VWS: 25-30 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 07W IS FORECAST TO MAINTAIN ITS GRADUAL POLEWARD CURVE TOWARD THE SEA OF OKHOTSK. OVER THE NEXT 12 HOURS, STRONG POLEWARD OUTFLOW ALOFT WILL LARGELY NEGATE STEADILY MOUNTING VERTICAL WIND SHEAR (VWS), RESULTING IN LITTLE TO NO INTENSITY CHANGE DURING THAT TIME. SHORTLY AFTER TAU 12, VWS TOGETHER WITH COOL DRY AIR ENTRAINING THE SYSTEM WILL BEGIN TO DRIVE INTENSITY VALUES DOWN. AT THE SAME TIME, THE SYSTEM WILL BEING TO INTERACT WITH A WEAK BAROCLINIC ZONE AS IT PROCEEDS POLEWARD OF THE 44TH PARALLEL, THIS WILL INITIATE EXTRA-TROPICAL TRANSITION (ETT). AS THE SYSTEM CONTINUES TO WEAKEN AND INTEGRATE INTO THE MID-LATITUDE TROUGH, IT WILL CONTINUE THROUGH ETT UNTIL ENTERING THE SEA OF OKHOTSK WHERE IT WILL COMPLETE ETT BY TAU 36. MODEL DISCUSSION: NUMERICAL MODELS AND RELIABLE MODEL INTENSITY GUIDANCE ARE BOTH IN GOOD AGREEMENT AND DEVIATE VERY LITTLE FROM THE MULTI-MODEL CONSENSUS. THE JTWC TRACK AND INTENSITY FORECASTS ARE THEREFOR PLACED CLOSE TO THEIR RESPECTIVE CONSENSUS MODELS WITH OVERALL HIGH CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH INTENSITY 0 - 72 HR: HIGH// NNNN