WDPN31 PGTW 300300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 28W (TRAMI) WARNING NR 38// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 28W (TRAMI), LOCATED APPROXIMATELY 229 NM SOUTH-SOUTHWEST OF IWAKUNI, JAPAN, HAS TRACKED NORTHEASTWARD AT 19 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM REMAINS EXPANSIVE AND HAS MAINTAINED A VERY LARGE AND RAGGED EYEWALL SURROUNDING AN 80 BY 100 NM RAGGED OBLONG EYE. FEEDER BANDS REMAIN DEEP AND EXTEND OVER 250 NM FROM THE CENTER. THE INITIAL POSITION IS BASED ON THE EYE FEATURE AND ON A TIGHT CLUSTER OF 300000Z AGENCY AND RADAR POSITION FIXES WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 90 KNOTS IS BASED ON EQUIVALENT DVORAK ESTIMATES OF T5.0/90 KNOTS FROM PGTW, RJTD, AND KNES. ENVIRONMENTAL ANALYSIS INDICATES THAT TY 28W IS IN STRONG (GREATER THAN 25 KNOT) VERTICAL WIND SHEAR (VWS); HOWEVER, THIS IS BEING OFFSET BY EXCELLENT RADIAL OUTFLOW WITH A STRONG POLEWARD CHANNEL INTO THE MID-LATITUDE TROUGH DIGGING IN FROM THE NORTHWEST AND THE STORM MOTION BEING IN-PHASE WITH THE UPPER LEVEL WIND VECTOR. SEA SURFACE TEMPERATURES (SSTS) HAVE COOLED TO 26 CELSIUS BUT REMAIN FAVORABLE. THE CYCLONE IS TRACKING ALONG THE NORTHWESTERN PERIPHERY OF THE DEEP-LAYERED SUBTROPICAL RIDGE TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY TRAMI WILL CONTINUE TO ACCELERATE NORTHEASTWARD AND IS NOW INTERACTING WITH KYUSHU, JAPAN. IT WILL TRACK QUICKLY ACROSS THE RUGGED JAPANESE TERRAIN AND SHORTLY AFTER TAU 18, THE CYCLONE WILL EXIT BACK INTO THE PACIFIC OCEAN, ALBEIT WITH MUCH COOLER SSTS, JUST EAST OF MISAWA. INCREASING VWS PLUS INTERACTION WITH THE JAPANESE ALPS WILL LEAD TO RAPID DECAY. CONCURRENTLY, THE SYSTEM HAS BEGUN EXTRA-TROPICAL TRANSITION AND BY TAU 24, WILL BECOME A STRONG GALE-FORCE COLD CORE LOW WITH AN EXPANDING WIND FIELD. DYNAMIC MODEL GUIDANCE IS IN VERY TIGHT AGREEMENT; THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN