WDPN31 PGTW 290300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 28W (TRAMI) WARNING NR 34//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 28W (TRAMI), LOCATED APPROXIMATELY 85 NM SOUTHWEST OF
KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWARD AT 08 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE
SYSTEM REMAINS EXPANSIVE AND HAS MAINTAINED A VERY LARGE 81-NM RAGGED
EYE. THE INITIAL POSITION IS BASED ON THE EYE FEATURE AND ON A
TIGHTLY GROUPED CLUSTER OF 281800Z 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 AND KNES.
ENVIRONMENTAL ANALYSIS INDICATES THAT TY 28W IS STILL IN LOW (5 TO 10
KNOT) VERTICAL WIND SHEAR (VWS) AND EXCELLENT RADIAL OUTFLOW. SEA
SURFACE TEMPERATURES ALSO REMAIN FAVORABLE AT 28 TO 29 CELSIUS. THE
CYCLONE IS TRACKING ALONG THE WESTERN EDGE OF THE SUBTROPICAL RIDGE
(STR) 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 HAS CRESTED THE STR AXIS AND WILL BEGIN TO
ACCELERATE NORTHEASTWARD, MAKING LANDFALL ALONG THE SOUTHWEST COAST
OF HONSHU, JAPAN, SHORTLY AFTER TAU 30. THE SYSTEM WILL QUICKLY DRAG 
ACROSS HONSHU AND BY TAU 48, WILL BE BACK ON THE PACIFIC OCEAN EAST
OF MISAWA. THE INITIAL EXPOSURE TO THE STRONG WESTERLIES ASSOCIATED
WITH AN APPROACHING MID-LATITUDE TROUGH, IN ADDITION TO THE
AFOREMENTIONED FAVORABLE CONDITIONS, WILL FUEL SLIGHT INTENSIFICATION
TO 100 KNOTS BY TAU 24. AFTERWARD, INCREASING VWS PLUS INTERACTION
WITH THE JAPANESE ISLANDS WILL LEAD TO GRADUAL DECAY. CONCURRENTLY,
THE SYSTEM WILL BEGIN EXTRA-TROPICAL TRANSITION  AROUND TAU 36 AND BY
TAU 48, WILL BECOME A STORM-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.//
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