WDPN31 PGTW 221500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (DOKSURI) WARNING NR 005// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 14.5N 130.3E INITIAL INTENSITY: 40 KTS GEOGRAPHIC REFERENCE: 806 NM SOUTHEAST OF TAIPEI, TAIWAN MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 03 KTS SIGNIFICANT WAVE HEIGHT: 16 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL STORM (TS) 05W (DOKSURI) CONTINUES TO SLOWLY CONSOLIDATE AND INTENSIFY, BUT AT A RELATIVELY LEISURELY RATE. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN ASYMMETRIC SYSTEM, WITH A BROAD BAND OF DEEP CONVECTION EXTENDING FROM NEAR THE ASSESSED LOW LEVEL CENTER (LLC) SOUTHWESTWARD IN A GRACEFUL ARC. DRY LOW TO MID-LEVEL AIR REMAINS FIRMLY ENTRENCHED TO THE NORTH, WHICH IS STILL INHIBITING CONVECTIVE DEVELOPMENT ON THE NORTHWESTERN FLANK OF THE CIRCULATION. THE LATEST FRAMES OF EIR CONFIRM THAT THE CONVECTION IS ALMOST LINEAR IN NATURE AND UNABLE TO PENETRATE WESTERN SIDE OF THE CIRCULATION. A 221326Z GPM 37GHZ MICROWAVE IMAGE IS SUGGESTIVE OF SOME LOW-LEVEL BANDS BEGINNING TO FORM ON THE WESTERN SIDE OF THE CIRCULATION, BUT THEY REMAIN VERY WEAK, WITH BROAD CONVECTIVE BANDS WRAPPING UP THE EASTERN SIDE. THE INITIAL POSITION IS ASSESSED WITH MEDIUM CONFIDENCE DUE TO THE DISORGANIZED NATURE OF THE LLCC, EVEN WITH THE HIGH RESOLUTION MICROWAVE IMAGERY. THE INITIAL INTENSITY OF 40 KNOTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE AGENCY DVORAK CURRENT INTENSITY ESTIMATES BETWEEN T2.5 AND T3.0, AS WELL AS THE SATCON AND DPRINT ESTIMATES OF 40 AND 39 KNOTS RESPECTIVELY. THE ENVIRONMENT CONTINUES TO IMPROVE, WITH THE TUTT-CELL TO THE NORTHEAST PROVIDING SOME ENHANCED EASTWARD OUTFLOW AS WELL AS ACTING LIKE A BLOCKER RUNNING A PICK, DISRUPTING THE NORTHEASTERLY FLOW ALOFT AND REDUCING EFFECTIVE SHEAR OVER TS 05W. THIS LOWERED SHEAR IS ALLOWING FOR OUTFLOW TO BEGIN EXPANDING RADIALLY OUTWARD, ESPECIALLY POLEWARD. SHEAR REMAINS LOW (5-10 KNOTS) AND SSTS ARE VERY WARM (30C) AND THE SYSTEM IS MOVING SLOWLY OVER AN AREA OF HIGH OHC EXCEEDING 90 KJ PER CM2. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF A DEEP LAYER SUBTROPICAL RIDGE (STR) TO THE NORTH. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS RJTD: T2.5 - 35 KTS RCTP: T3.0 - 45 KTS KNES: T2.5 - 35 KTS CIMSS SATCON: 40 KTS AT 221038Z CIMSS ADT: 34 KTS AT 221140Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE POLEWARD AND EQUATORWARD OTHER FACTORS: ENHANCED OUTFLOW TO THE EAST INTO A TUTT-CELL; LOW TO MID-LEVEL DRY AIR TO THE NORTH. ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: HIGH INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: THROUGH THE NEXT 24 HOURS OR SO, TS 05W WILL CONTINUE TO TRACK GENERALLY WESTWARD UNDER THE INFLUENCE OF THE DEEP STR FIRMLY ENTRENCHED TO THE NORTH. THROUGH THIS PERIOD, THE SYSTEM WILL SLOWLY BUT STEADILY INTENSIFY AS IT CONTINUES TO CONSOLIDATE IN THE LOW LEVELS AND THE UPPER-LEVEL OUTFLOW PATTERN CONTINUES TO EVOLVE IN ITS FAVOR. BY TAU 36, THE UPPER-LEVEL STEERING PATTERN BEGINS TO CHANGE AS THE STEERING RIDGE SHIFTS ITS CENTER POSITION EASTWARD, AND THE RIDGING OVER THE EAST CHINA SEA (ECS) BEGINS TO ERODE AHEAD OF AN APPROACHING UPPER-LEVEL LOW MOVING EAST OUT OF NORTHERN CHINA. THE COMBINATION OF EFFECTS WILL ALLOW TS 05W TO TURN ONTO A NORTHWESTWARD TRACK AFTER TAU 36, WHICH WILL CONTINUE THROUGH THE END OF THE FORECAST PERIOD. IN TERMS OF INTENSITY, THE SYSTEM IS EXPECTED TO INTENSIFY AT A RATE OF ABOUT 10 KNOTS PER 12 HOURS THROUGH TAU 36. AFTER THIS POINT, THE RATE OF INTENSIFICATION WILL DRAMATICALLY INCREASE. AN UPPER-LEVEL LOW SITTING AT THE BASE OF A SHARP TROUGH SOUTH OF TOKYO AT PRESENT, WILL DEEPEN AND DIVE SOUTHWARD AND SLIDE SOUTHWESTWARD TO A POINT SOUTH OF KYUSHU BY TAU 36. THE POSITIONING OF THIS CUTOFF LOW WILL PROVIDE TS 05W WITH A ROBUST POLEWARD OUTFLOW CHANNEL, WHICH WILL SUPPORT A PERIOD OF RAPID INTENSIFICATION (RI), KICKING OFF IN EARNEST AFTER TAU 36. THE CURRENT PEAK OF 115 KNOTS IS EXPECTED TO OCCUR AROUND OR JUST PRIOR TO TAU 96, BUT FURTHER INTENSIFICATION IS POSSIBLE BETWEEN TAU 96 AND TAIWAN LANDFALL, WHICH CANNOT BE CAPTURED IN THE FORECAST POINTS. A PEAK INTENSITY EXCEEDING 120 KNOTS IS POSSIBLE AS THE SYSTEM WILL CROSS OVER A POOL OF VERY WARM (30-31C) WATERS WITH HIGH OHC (90 KJ PER CM2) WHICH SITS JUST EAST OF TAIWAN AND WILL BY THAT TIME BE TAPPING INTO A VERY STRONG POLEWARD OUTFLOW CHANNEL. LANDFALL ALONG THE NORTHERN HALF OF TAIWAN IS EXPECTED AFTER TAU 96, WITH THE TRACK AFTER LANDFALL HIGHLY UNCERTAIN DUE TO TERRAIN INDUCED TRACK VARIABILITY THAT DEPENDS UPON THE EXACT LANDFALL LOCATION. MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH THE FIRST 48 HOURS, WITH THE BULK OF THE GUIDANCE CONTAINED WITHIN A 95NM ENVELOPE, WITH THE NAVGEM AND COAMPS-TC (NAVGEM) BEING NOTABLE OUTLIERS IN PERSISTING ON A WESTWARD TRACK TOWARDS LUZON THROUGH TAU 72. THE GFS AND GEFS ENSEMBLE DIVERGE FROM THE PACK AROUND TAU 36 AND ARE THE EASTERN OUTLIERS FROM THAT POINT THROUGH THE REST OF THE FORECAST. TRACK SPREAD WIDENS UP TO 180NM BY TAU 72 AND 440NM BY TAU 120. OF NOTE WITH THIS RUN, GFS AND GEFS HAVE SHIFTED WEST AND NOW TRACK OVER ISHIGAKIJIMA, THE ECMWF HAS SHIFTED TO THE WEST AND NOW TRACKS THE SYSTEM INTO THE LUZON STRAIT BY TAU 96, HAVING BEEN OVER CENTRAL TAIWAN ON THE PREVIOUS RUN. FINALLY, THE LATEST ECENS AND MOGREPS ENSEMBLES ALSO SHIFT WESTWARD WITH THIS RUN. THE TOTALITY OF THESE CHANGES SUPPORT A SLIGHT ADJUSTMENT OF THE JTWC TRACK TO THE WEST FROM TAU 72 TO TAU 120, BUT ALSO INTRODUCE INCREASED UNCERTAINTY INTO THE LONG-RANGE FORECAST BEYOND TAU 72. THE JTWC FORECAST TRACK LIES JUST EAST OF THE CONSENSUS MEAN WITH MEDIUM TRENDING TO LOW CONFIDENCE IN THE LATER TAUS. INTENSITY GUIDANCE IS IN OVERALL GOOD AGREEMENT, WITH THE GFS AND HAFS-A SUPPORTING A SLOW BUT STEADY INTENSIFICATION TREND TO ABOUT TAU 48 FOLLOWED BY RI THEREAFTER. MULTIPLE RI AIDS ARE ALSO TRIGGERED WITH THIS RUN. THE CONSENSUS MEAN, EVEN TAKING INTO ACCOUNT THE RI AIDS, PEAKS AT JUST 105 KNOTS AT TAU 72 FOLLOWED BY A GENERAL WEAKENING TREND. THE HAFS-A SEEMS TO BE MORE REALISTIC, PEAKING AT 120 KNOTS BY TAU 84. THE NON-INTERPOLATED HAFS-A ACTUALLY PEAKS JUST PRIOR TO LANDFALL AROUND 135 KNOTS. ADDITIONALLY, THE LATEST COAMPS-TC ENSEMBLE RI PROBABILITIES HAVE INCREASED TO 70 PERCENT BETWEEN TAU 48 AND TAU 72. THE JTWC FORECAST LIES SLIGHTLY BELOW THE MEAN THROUGH TAU 48 THEN TRANSITIONS RAPIDLY TO TRACK THE HAFS-A FORECAST THROUGH TAU 120. CONFIDENCE IS MEDIUM TRENDING TO LOW IN THE EXTENDED FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: LOW// NNNN