Tropical Storm TRAMI Advisory Sat Sep 29

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 28W (TRAMI) WARNING NR 31//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 28W (TRAMI), LOCATED APPROXIMATELY 205 NM SOUTH OF
KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWESTWARD AT 07 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS TY
28W CONTINUES TO HAVE A WIDE AND RAGGED EYE AND HAS MAINTAINED DEEP
CONVECTION AROUND THE EYE, ESPECIALLY IN THE NORTHEAST QUADRANT. THE
INITIAL POSITION IS BASED ON A 280600Z HIMAWARI VISIBLE SATELLITE
IMAGE WHICH SHOWS THE LARGE CLOUD FILLED EYE. THE INITIAL INTENSITY
OF 90 KNOTS IS BASED ON A DVORAK CURRENT INTENSITY (CI) ESTIMATE OF
T5.0 (90 KNOTS) AND AN ADT CI OF T4.9 (87 KNOTS). ENVIRONMENTAL
ANALYSIS SHOWS THAT TY 28W IS EXPERIENCING FAVORABLE VERTICAL WIND
SHEAR (5 TO 10 KNOTS) AND HAS EXCELLENT RADIAL OUTFLOW. SEA SURFACE
TEMPERATURES REMAIN FAVORABLE, BETWEEN 28 AND 29 DEGREES CELSIUS. TY
28W IS TRACKING NORTHWESTWARD ALONG THE WESTERN EDGE OF THE
SUBTROPICAL RIDGE (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 WILL CONTINUE TO TRACK TO THE NORTHWEST ALONG THE
WESTERN PERIPHERY OF THE STR THROUGH TAU 12. AFTER TAU 12, TY 28W
WILL BEGIN TO TRACK NORTHEASTWARD AS IT ROUNDS THE STR AXIS.
CONTINUED FAVORABLE SEA SURFACE TEMPERATURES, UPPER LEVEL OUTFLOW,
AND VERTICAL WIND SHEAR WILL ALLOW TY 28W TO RE-INTENSIFY TO 105
KNOTS BY TAU 36 AS IT TRACKS NORTHEASTWARD AROUND THE STR. AN
APPROACHING SHORTWAVE TROUGH WILL HELP TO ACCELERATE TY 28W AS IT
TRACKS NORTHEASTWARD. TY 28W WILL BEGIN EXTRATROPICAL TRANSITION
(ETT) BY TAU 48 AS IT INTERACTS WITH THE TROUGH AND ACCELERATES
NORTHEASTWARD. TY 28W WILL COMPLETE ETT BY TAU 72. DYNAMIC MODEL
GUIDANCE IS IN AGREEMENT THAT TY 28W WILL TRACK NORTHWESTWARD AND
THEN NORTHEASTWARD AROUND THE STR. THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK.//
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