WDPN31 PGTW 090900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (DOLPHIN) WARNING NR 054// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 28.1N 121.9E INITIAL INTENSITY: 75 KTS GEOGRAPHIC REFERENCE: 181 NM NORTH OF TAIPEI, TAIWAN MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 12 KTS SIGNIFICANT WAVE HEIGHT: 30 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN EXPANSIVE SYSTEM WITH OUTER RAINBANDS EXTENDING FROM TAIWAN TO SHANGHAI AND A VERY COMPACT, CLOUD-FILLED EYE EMBEDDED WITHIN A MUCH SMALLER INNER CORE OF DEEP CONVECTION. ANIMATED RADAR DATA SHOWS THE EYE BECOMING MORE RAGGED AND LESS-DEFINED AS IT APPROACHES THE COAST OF ZHEJIANG PROVINCE, CHINA BUT THE WESTERN EYEWALL IN PARTICULAR IS WELL-DEFINED AND NOW BRUSHING THE COAST NEAR SHITANGZHEN, CHINA. SURFACE OBSERVATIONS FROM DACHEN DAO TO THE NORTH REPORTED EAST-NORTHEAST WINDS OF 45 KNOTS AND AN MSLP READING OF 965 MB AT 0600Z. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE RADAR DATA AND THE EYE FEATURE IN THE MSI. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE. SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES CONTINUE TO VASTLY OUTPERFORM THE MAJORITY OF THE OBJECTIVE INTENSITY ESTIMATES (EXCEPT THE SATCON), WHICH ARE STRUGGLING WITH THE COMPLEX STRUCTURE OF THE SYSTEM. THE ENVIRONMENT REMAINS FAVORABLE, BUT THE IMMINENT LANDFALL MEANS THE SYSTEM WILL NOT HAVE TIME TO TAKE ADVANTAGE OF THE FAVORABLE CONDITIONS. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF AN EXTENSION OF THE SUBTROPICAL RIDGE (STR) CENTERED OVER SOUTHERN JAPAN AND EXTENDING NORTHWEST TO THE SHANDONG PENINSULA. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.5 - 77 KTS RJTD: T5.0 - 90 KTS RCTP: T4.0 - 65 KTS KNES: T5.0 - 90 KTS CIMSS SATCON: 80 KTS AT 090600Z CIMSS ADT: 51 KTS AT 090600Z CIMSS AIDT: 66 KTS AT 090600Z CIMSS D-MINT: 60 KTS AT 090427Z CIMSS D-PRINT: 63 KTS AT 090530Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL OTHER FACTORS: PROXIMITY TO LAND. ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TYPHOON (TY) 12W WILL MAKE LANDFALL ALONG THE SOUTHEASTERN CHINESE COAST, SOUTH OF THE CITY OF TAIZHOU WITHIN THE NEXT FEW HOURS. THE WESTERN EYEWALL IS ALREADY BRUSHING THE COASTLINE AND THE LATEST RADAR ANIMATIONS SUGGEST THE SYSTEM MAY ATTEMPT ONE MORE TROCHOIDAL WOBBLE SOUTHWESTWARD BEFORE CROSSING THE COAST. OVERALL, THE SYSTEM WILL TRACK WESTWARD ALONG THE SOUTHERN FLANK OF THE STR BUILDING TO THE NORTH FOR THE NEXT 12 HOURS, THEN TURN NORTHWESTWARD AS THE RIDGE RECEDES SLIGHTLY EASTWARD. NO CHANGE IN INTENSITY IS EXPECTED IN THE SHORT TIME PRIOR TO LANDFALL. AFTER LANDFALL, THE SYSTEM WILL RAPIDLY WEAKEN AND DISSIPATE OVER EAST-CENTRAL CHINA WITHIN 48 HOURS. MODEL DISCUSSION: TRACK GUIDANCE IS IN STRONG AGREEMENT, WITH MINIMAL CROSS-TRACK SPREAD THROUGH THE FORECAST PERIOD, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK, WHICH IS PLACED NEAR THE AI CONSENSUS MEAN THROUGH THE FORECAST PERIOD. INTENSITY GUIDANCE IS ALSO IN STRONG AGREEMENT DEPICTING RAPID WEAKENING THROUGH THE FORECAST PERIOD, LENDING HIGH CONFIDENCE TO THE JTWC INTENSITY FORECAST. FORECAST CONFIDENCE: TRACK 00-72 HR: HIGH INTENSITY 00-72 HR: HIGH// NNNN

WDPN32 PGTW 092100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (PEILOU) WARNING NR 012// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 20.5N 145.8E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 411 NM NORTH OF ANDERSEN AFB MOVEMENT PAST 6 HOURS: EASTWARD AT 15 KTS SIGNIFICANT WAVE HEIGHT: 13 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS THE LOW LEVEL CIRCULATION CENTER (LLCC) TROPICAL STORM (TS) 13W (PEILOU) FURTHER OBSCURED BY PERSISTENT CONVECTION CENTERED OVER THE EASTERN FLANK OF THE SYSTEM. A COMPACT CIRCULATION IS SEEN IN A 091620Z AMSR2 89 GHZ MICROWAVE IMAGE AS WELL AS A DEEP BAND OF CONVECTION PARTIALLY WRAPPING ON THE EASTERN AND NORTHERN PERIPHERY. ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE CONDITIONS WITH WARM (29-30 C) SEA SURFACE TEMPERATURES, LOW (5-10 KTS) VERTICAL WIND SHEAR, AND MODERATE OUTFLOW ALOFT DUE TO A UPPER LEVEL TROUGH SITUATED TO THE NORTHEAST. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE PARTIALLY EXPOSED LOW LEVEL WRAPPING CLOUDS AND REFERENCED MICROWAVE IMAGE. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED ON A PARTIAL 091449Z OSCAT IMAGE WITH 30 KTS DISPLACED TO THE SOUTHWEST AS WELL AS THE AGENCY DVORAK FIXES AND OBJECTIVE ESTIMATES LISTED BELOW. INITIAL WIND RADII BASIS: WIND RADII ADJUSTED BASED ON A 091155Z METOP-C ASCAT IMAGE CURRENT STEERING MECHANISM: LOW-LEVEL MONSOONAL WESTERLIES AND A NEAR EQUITORIAL RIDGE (NER) CENTERED TO THE SOUTHWEST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.0 - 30 KTS RJTD: T1.5 - 25 KTS RCTP: T2.5 - 35 KTS KNES: T2.0 - 30 KTS CIMSS ADT: 37 KTS AT 091730Z CIMSS AIDT: 38 KTS AT 091730Z CIMSS D-MINT: 35 KTS AT 091700Z CIMSS D-PRINT: 32 KTS AT 091900Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE EASTWARD OTHER FACTORS: UPPER LEVEL TROUGH POSITIONED CLOSELY TO THE NORTHWEST ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: HIGH INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 13W IS FORECAST TO TRACK EASTWARD UNTIL TAU 12 AND THEN TURN NORTHEASTWARD AS IT FOLLOWS THE STEERING INFLUENCE OF BOTH A NEAR EQUATORIAL RIDGE (NER) CENTERED TO THE SOUTHWEST AND THE STRONG LOW-LEVEL MONSOONAL WESTERLIES. IN REGARDS TO INTENSITY, A SLIGHT INTENSIFICATION PERIOD IS FORECAST AS THE UPPER LEVEL TROUGH TO THE NORTHWEST REMAINS FAVORABLY POSITIONED TO PROMOTE INCREASED OUTFLOW ALOFT. FOLLOWING TAU 24 TO 36, A WEAKENING TREND IS EXPECTED AND TS 13W IS FORECAST TO ULTIMATELY DISSIPATE BY TAU 60 AS IT EXPERIENCES DRY AIR ENTRAINMENT AND THE UPPER LEVEL TROUGH ULTIMATELY PASSES OVER THE SYSTEM INHIBITING OUTFLOW, AN OUTCOME SUPPORTED ON ALL GLOBAL DETERMINISTIC MODEL FIELDS. MODEL DISCUSSION: TRACK MODEL GUIDANCE IS IN GOOD AGREEMENT FOR THE REMAINDER OF THE FORECAST PERIOD OF THE GENERAL NORTHEASTWARD TRACK, WITH THE LARGER AREA OF DISAGREEMENT BEING THE TRACK SPEED. DISREGARDING NAVGEM AS TOO SLOW OF AN OUTLIER, THE ALONG TRACK SPEED AT TAU 60 IS 200 NM. THE OFFICIAL JTWC FORECAST TRACK IS PLACED WITH HIGH CONFIDENCE, IN BETWEEN THE MULTI-MODEL CONSENSUS AND AI CONSENSUS TRACKS AND SPEEDS. INTENSITY MODEL GUIDANCE IS IN LESS AGREEMENT AS OUTLIERS OF THE DECAY-SHIPS (GFS AND NAVGEM BASED) PREDICT A STRONG INTENSIFICATION OUT TO TAU 96, WHILE THE REMAINDER OF THE GUIDANCE IS IN BETTER AGREEMENT OF A SHORT TERM INTENSIFICATION FOLLOWED BY A LONGER WEAKENING TREND. THE OFFICIAL JTWC FORECAST INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE FOR THE REMAINDER OF THE FORECA…

WDPN33 PGTW 092100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (CHAN-HOM) WARNING NR 012// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 33.2N 150.2E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 535 NM EAST OF YOKOSUKA, JAPAN MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 10 KTS SIGNIFICANT WAVE HEIGHT: 14 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS THE FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) OF TROPICAL STORM (TS) 14W (CHAN-HOM) WITH ONLY A FEW SMALL PUFFS OF FLARING CONVECTION CONFINED TO THE NORTHEAST QUADRANT. ENVIRONMENTAL CONDITIONS REMAIN MARGINALLY FAVORABLE AS THE UPPER LEVEL LOW SITUATED JUST TO THE NORTHEAST OF 14W CONTINUES TO CAUSE CONVERGENCE ALOFT, DRY AIR ENTRAINMENT ON THE WESTERN AND SOUTHERN FLANKS OF 14W, AND LOW (10-15 KTS) NORTHWESTERLY SHEAR, ALL EVIDENT IN EIR. THESE CONDITIONS ARE OFFSET ONLY MARGINALLY BY SSTS OF 26-27 C. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EXPOSED LLCC. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE HEDGING ABOVE AGENCY DVORAK FIXES AND CIMSS OBJECTIVE ESTIMATES LISTED BELOW AS THE DVORAK METHOD STRUGGLES WITHOUT PERSISTENT CONVECTION. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHWESTERN EXTENSION OF A SUBTROPICAL RIDGE (STR) CENTERED TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.0 - 30 KTS RJTD: T2.0 - 30 KTS RCTP: T2.0 - 30 KTS CIMSS SATCON: 41 KTS AT 091800Z CIMSS ADT: 25 KTS AT 091800Z CIMSS AIDT: 29 KTS AT 091800Z CIMSS D-MINT: 33 KTS AT 091605Z CIMSS D-PRINT: 30 KTS AT 091800Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY UNFAVORABLE VWS: 10-15 KTS SST: 26-27 CELSIUS OUTFLOW: WEAK EASTWARD OTHER FACTORS: UPPER LEVEL LOW POSITIONED JUST TO THE NORTH OF THE SYSTEM AND DRY AIR ENTRAINMENT ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM 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 14W HAS BEGUN ITS NORTH-NORTHWESTWARD TRACK AFTER COMPLETING A SMALL COUNTER-CLOCKWISE LOOP EARLIER, EVIDENT IN EIR. IT IS EXPECTED TO CONTINUE NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE (STR) CENTERED TO THE NORTHEAST NEAR THE ALEUTIAN ISLANDS. AT TAU 36 THIS STR IS EXPECTED TO BUILD A WESTWARD EXTENSION LEADING TO A FORECAST WESTWARD TURN OF TS 14W IN RESPONSE. THE SYSTEM IS FORECAST TO MAKE LANDFALL OVER CENTRAL HONSHU JUST AFTER TAU 36 AND REEMERGE INTO THE SEA OF JAPAN BY TAU 48 AS IT INCREASES IN TRACK SPEED. THIS INCREASE IN TRACK SPEED IS DUE TO THE MORE DEFINED STEERING PATTERN AS TS 14W CROSSES OVER JAPAN. IN REGARDS TO INTENSITY, TS 14W IS FORECAST TO EXPERIENCE A BRIEF INTENSIFICATION BETWEEN TAUS 12 AND 36 AS THE UPPER LEVEL LOW FILLS AND A SEPARATE UPPER LEVEL TROUGH TO THE NORTHWEST CAUSES INCREASED OUTFLOW. PRIOR TO LANDFALL, TS 14W IS THEN EXPECTED TO ENCOUNTER INCREASED DRY AIR ENTRAINMENT AND COOLING SSTS OFF THE COAST OF HONSHU, LEADING TO A WEAKENING TREND BEFORE IT BEGINS TERRAIN INTERACTION, FURTHER DECREASING INTENSITY BEFORE IT TRACKS INTO THE SEA OF JAPAN. INCREASED UNFAVORABLE CONDITIONS OF INCREASED DRY AIR AND STRONG UPPER LEVEL NORTHERLIES IN THE SEA OF JAPAN ARE EXPECTED TO BEGIN SUBTROPICAL TRANSITION (STT) BY TAU 60 AND COMPLETE STT AND DISSIPATE OVER WATER BY TAU 72, PRIOR TO LANDFALL OVER THE KOREAN PENINSULA. MODEL DISCUSSION: MODEL TRACK GUIDANCE IS IN GOOD AGREEMENT IN THE SHORT TERM WITH A CROSS TRACK SPREAD OF 55 NM JUST PRIOR TO THE FORECAST LANDFALL OVER JAPAN. ONCE IN THE SEA OF JAPAN IT EXPANDS TO 100 NM BY TAU 7…