MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 28W (TRAMI) WARNING NR 26// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 28W (TRAMI), LOCATED APPROXIMATELY 302 NM SOUTH- SOUTHEAST OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL (MSI) SATELLITE IMAGERY SHOWS TY 28W MAINTAINS A WIDE EYE, AND IS MAINTAINING DEEP CONVECTION IN THE EYEWALL. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE WIDE EYE IN THE MSI LOOP. THE INITIAL INTENSITY IS MAINTAINED AT 90 KNOTS, IN AGREEMENT WITH THE PGTW AND KNES DVORAK CURRENT INTENSITY (CI) ESTIMATES OF T5.0 (90 KTS), AND BELOW THE RJTD ESTIMATE OF T5.5 (102 KTS), AND SLIGHTLY BELOW A 262000Z SATCON ESTIMATE OF 93 KNOTS. ENVIRONMENTAL ANALYSIS SHOWS TY 28W IS EXPERIENCING FAVORABLE VERTICAL WIND SHEAR (5 TO 10 KNOTS) ALONG WITH GOOD RADIAL OUTFLOW, WHICH IS BEING ENHANCED BY A PASSING MIDLATITUDE TROUGH TO THE NORTH. SEA SURFACE TEMPERATURES REMAIN FAVORABLE NEAR 28 DEGREES CELSIUS, ALTHOUGH THE SLOW MOTION OF TY 28W IS ALLOWING FOR UPWELLING, WHICH IS REDUCING THE AVAILABLE OCEAN HEAT CONTENT (OHC) FOR THE SYSTEM, LEADING IT TO MAINTAIN ITS INTENSITY IN THE MIDST OF AN OTHERWISE FAVORABLE ENVIRONMENT. TY 28W IS ALMOST QUASI-STATIONARY IN A WEAK STEERING ENVIRONMENT WHILE IN BETWEEN A SUBTROPICAL RIDGE (STR) LOCATED TO THE WEST AND A SECOND STR LOCATED TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 28W IS FORECAST TO TRACK SLOWLY NORTH TO NORTHWESTWARD IN THE AMBIGUOUS STEERING ENVIRONMENT WHILE MAINTAINING ITS INTENSITY, CAUGHT IN A BALANCE BETWEEN FAVORABLE OUTFLOW AND LOW VWS, AND THE UNFAVORABLE LOWER OHC. AFTER TAU 12, THE STR TO THE EAST WILL BUILD, BECOME THE DOMINANT STEERING FEATURE, AND ALLOW TY 28W TO INCREASE FORWARD MOTION AND TRACK NORTHWESTWARD THROUGH TAU 36. BY TAU 36, TY 28W WILL ENCOUNTER AN AREA OF WARM (28-30 C) SSTS THAT IT HAS NOT ALREADY CHURNED UP, WHICH WILL ALLOW FOR A PERIOD OF RE- INTENSIFICATION, REACHING 110 KTS BY TAU 72. MODELS ARE IN AGREEMENT THAT TY 28W WILL TRACK NORTHWESTWARD IN THE NEAR-TERM, WITH NAVGEM A NOTABLE OUTLIER TO THE WEST DUE TO IT BUILDING IN A MORE ROBUST STR TO THE EAST. AFTER TAU 48, TY 28W WILL HAVE ROUNDED THE RIDGE AND WILL BEGIN ACCELERATING TO THE NORTHEAST. A MIDLATITUDE TROUGH MOVING INTO THE YELLOW SEA REGION WILL ALSO ENHANCE OUTFLOW, CONTRIBUTING TO THE RE-INTENSIFICATION TREND. THE JTWC FORECAST TRACK IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS. DUE TO THE 368 NM MODEL SPREAD AT TAU 72, THERE IS LOW CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK. C. AFTER TAU 72, TY 28W WILL CONTINUE TO ACCELERATE TO THE NORTHEAST, PULLED BY THE MIDLATITUDE WESTERLIES AND AFOREMENTIONED PASSING TROUGH. INCREASED VERTICAL WIND SHEAR, COOLER SEA SURFACE TEMPERATURES, AND EVENTUAL LAND INTERACTION WILL WEAKEN THE SYSTEM AS IT TRACKS NORTHEASTWARD. TY 28W WILL BE EMBEDDED IN THE BAROCLINIC ZONE AND BEGIN EXTRA-TROPICAL TRANSITION (ETT) BY TAU 96, AND WILL COMPLETE ETT BY TAU 120. THE JTWC FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS. MODEL GUIDANCE IS IN GOOD AGREEMENT THAT TY 28W WILL TRACK NORTHEASTWARD, BUT MODELS DIFFER ON THE TRACK SPEED. THEREFORE, THERE IS LOW CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK.// NNNN NNNN