WDPN31 PGTW 260300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 18W (JELAWAT) WARNING NR 23// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON (STY) 18W (JELAWAT), LOCATED APPROXIMATELY 360 NM EAST-NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON SATELLITE EYE FIXES FROM PGTW AND RJTD AND A 252140Z CORIOLIS MICROWAVE SATELLITE IMAGE. THE CURRENT INTENSITY OF 135 KNOTS IS CONSISTENT WITH RECENT DVORAK T-NUMBER ESTIMATES FROM PGTW AND RJTD AS WELL AS AUTOMATED INTENSITY ESTIMATES FROM CIRA AND CIMSS. RECENT ANIMATED WATER VAPOR SATELLITE IMAGERY SHOWS THAT DEEP CONVECTION SURROUNDING A 15 NM EYE HAS WARMED SLIGHTLY OVER THE PAST SIX HOURS. A 252359Z SSMIS IMAGE SHOWS A SINGLE CONTINUOUS RING OF DEEP CONVECTION AROUND THE EYE, SUGGESTING THAT ANY RESTRUCTURING OF THE EYEWALL THAT MAY HAVE TAKEN PLACE OVER THE PAST 12 HOURS IS NEARLY COMPLETE. STY 18W IS TRACKING ALONG THE WESTERN PERIPHERY OF A BUILDING NEAR-EQUATORIAL RIDGE SITUATED TO THE EAST. 3. FORECAST REASONING. A. THE EXTENDED TRACK FORECAST HAS BEEN SHIFTED SLIGHTLY EQUATORWARD, CONSISTENT WITH A SHIFT IN THE NUMERICAL MODEL GUIDANCE. B. STY 18W WILL CONTINUE TRACKING GENERALLY NORTHWESTWARD OVER THE NEXT 48 HOURS ALONG THE WESTERN AND SOUTHWESTERN PERIPHERIES OF THE CURRENT STEERING RIDGE. THE RIDGE IS EXPECTED TO REORIENT AHEAD OF AN APPROACHING MIDLATITUDE TROUGH AROUND TAU 48, INDUCING A SLOWER TRANSLATIONAL SPEED FOLLOWED BY A SHARP TURN TO THE EAST- NORTHEAST. FAVORABLE UPPER-LEVEL CONDITIONS AND PASSAGE OVER VERY WARM WATER WILL ENABLE STY 18W TO REMAIN A SUPER TYPHOON OR VERY STRONG TYPHOON FOR THE NEXT 24 HOURS. THEREAFTER, THE PERIPHERAL UPPER-LEVEL FLOW AROUND THE BUILDING NEAR-EQUATORIAL RIDGE WILL RESTRICT OUTFLOW AND VERTICAL WIND SHEAR WILL INCREASE SLIGHTLY, INDUCING SLOW WEAKENING THROUGH TAU 72. THE NUMERICAL MODELS ARE IN FAIR AGREEMENT THROUGH THIS FORECAST PERIOD WITH JGSM REMAINING THE LEFT OUTLIER AND WBAR THE RIGHT OUTLIER. GIVEN FAIR AGREEMENT AMONG THE MODELS AND ONLY A SLIGHT SHIFT IN THE MULTI- MODEL CONSENSUS FROM THE PREVIOUS RUN, THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK THROUGH TAU 72. C. IN THE EXTENDED PERIOD, STY 18W IS EXPECTED TO TRACK EAST- NORTHEASTWARD ALONG THE NORTHERN PERIPHERY OF THE STEERING RIDGE AND BEGIN INTERACTING WITH THE AFOREMENTIONED MIDLATITUDE TROUGH, WHICH WILL INDUCE THE FIRST STAGE OF EXTRATROPICAL TRANSITION BEFORE TAU 96. THE CYCLONE WILL ENCOUNTER INCREASING VERTICAL WIND SHEAR AND PASS OVER COOLER AS IT ACCELERATES NORTHEASTWARD BETWEEN TAU 96 AND TAU 120 AND TRANSITION INTO A STRONG MIDLATITUDE LOW PRESSURE SYSTEM. THE MODELS CONTINUE TO COME INTO BETTER AGREEMENT REGARDING POST-RECURVATURE TRACK SPEEDS, ALTHOUGH THE GFDN CONTINUES TO SHOW AN UNEXPECTEDLY RAPID TRACK INTO THE WESTERLY FLOW PATTERN. THE CURRENT TRACK FORECAST IS SLIGHTLY SLOWER THAN THE CONSENSUS TO OFFSET THE IMPACT OF THE GFDN FORECAST ON THE CONSENSUS. GIVEN TRACK SPEED FORECAST DISPARITIES, THERE REMAINS LOW CONFIDENCE IN THE EXTENDED FORECAST TRACK.// NNNN