Tropical Storm BOLAVEN Advisory Sa, 28.08.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (BOLAVEN) WARNING NR 32//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 16W (BOLAVEN), LOCATED APPROXIMATELY 280 NM SOUTH-
SOUTHWEST OF SEOUL, SOUTH KOREA, HAS TRACKED NORTHWARD AT 16 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCE INFRARED (EIR) SATELLITE
IMAGERY INDICATES THAT TY 16W'S DEEP CONVECTION HAS CONTINUED TO
WEAKEN OVER THE PAST SIX HOURS BUT THE SYSTEM HAS MAINTAINED TIGHTLY-
CURVED CONVECTIVE BANDING WRAPPING INTO A WELL-DEFINED AND LARGE LOW-
LEVEL CIRCULATION CENTER. A 271655Z AMSU-B IMAGE IS BEGINNING TO
SHOW THE BANDING BREAKING DOWN AND TY 16W IS STARTING TO LOSE ITS
ORGANIZATION. THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION BASED
ON THE AFOREMENTIONED IMAGERY AND RADAR FROM THE KOREAN
METEOROLOGICAL ADMINISTRATION. THE INITIAL INTENSITY IS ASSESSED AT
70 KNOTS IS BASED ON AN AVERAGE OF DVORAK ESTIMATES AMONGST RJTD,
KNES AND PGTW. UPPER LEVEL ANALYSIS REVEALS THAT TY 16W IS TRACKING
ALONG THE WESTERN PERIPHERY OF THE DEEP SUBTROPICAL RIDGE (STR)
CENTERED OVER CENTRAL JAPAN AND IS RECEIVING OUTFLOW TO THE SOUTH
FROM A TUTT CELL NORTH OF GUAM AND IS BEGINNING TO RECEIVE POLAR
OUTFLOW INTO THE WESTERLIES. VERTICAL WIND SHEAR IS MODERATE AT 10
TO 20 KNOTS.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY 16W IS FORECAST TO CONTINUE TRACKING NORTHWARD ALONG THE
WESTERN EDGE OF THE STR THROUGH TAU 12 AND SHOULD ACCELERATE AHEAD
OF THE DEEP UPPER-LEVEL TROUGH THAT IS DIGGING OVER EASTERN CHINA.
AFTER TAU 12, SEA SURFACE TEMPERATURES WILL DROP SIGNIFICANTLY AND
VERTICAL WIND SHEAR WILL RAPIDLY INCREASE WHICH WILL WEAKEN THE
SYSTEM AS IT TRACKS NORTH. THERE IS UNCERTAINTY IN THE INTENSITY
FORECAST DURING THIS STAGE OF THE TRACK BUT TY 16W CONTINUES TO
MAINTAIN AN EXTENSIVE AREA OF GALE-FORCE WINDS AND GREATEN THAN GALE-
FORCE WINDS WHICH ARE CURRENTLY BEING OBSERVED ON CHEJU-DO (RKPC)
WHICH IS APPROXIMATELY 90 NM AWAY FROM THE STORM CENTER AND
EXPERIENCING 45 KNOT WINDS SUSTAINED. TY 16W WILL BEGAN TO INTERACT
WITH THE BAROCLINIC ZONE IN THE NEXT 24 HOURS AND WILL COMPLETE
EXTRATROPICAL TRANSITION BY TAU 36 AS A STRONG EXTRATROPICAL LOW.
THERE IS HIGH CONFIDENCE IN THE TRACK FORECAST BASED ON THE TIGHT
MODEL SPREAD WITH THE OFFICIAL FORECAST BEING SLIGHLTY FASTER THAN
CONSENSUS AND FAVORING THE JGSM SOLUTION.//
NNNN
NNNN