Tropical Storm BOLAVEN Advisory Pzt, 27.08.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (BOLAVEN) WARNING NR 28//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 16W (BOLAVEN), LOCATED APPROXIMATELY 75 NM NORTH-
NORTHWEST OF KADENA AB, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT
10 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE
IMAGERY DEPICTS A WELL-ORGANIZED SYSTEM WITH A SMALL 9-NM EYE.
THE SMALL EYE PASSED DIRECTLY OVER OKINAWA AND WAS WELL
OBSERVED BY RADAR. A 261706Z AMSU IMAGE DEPICTS THE INNER EYEWALL
STILL PRESENT, BUT BEING CUT OFF BY A LARGER SECONDARY EYEWALL AS
THE ONGOING EYEWALL REPLACEMENT CYCLE (ERC) NEARS COMPLETION. THERE
IS HIGH CONFIDENCE IN THE INITIAL POSITION BASED ON THE SMALL EYE
FEATURE AND RADAR FIXES FROM JAPAN. THE INITIAL INTENSITY IS
ASSESSED AT 105 KNOTS BASED ON AN AVERAGE OF DVORAK DATA-T ESTIMATES
RANGING FROM 90-102 KNOTS FROM PGTW AND RJTD, RESPECTIVELY. THUS
FAR, THE HIGHEST REPORTED WINDS FROM OKINAWA WERE 90 KNOTS GUSTING
TO 120 KNOTS AT 2140L TIME. ANIMATED WATER VAPOR IMAGERY INDICATES
RADIAL OUTFLOW WITH GOOD OUTFLOW INTO A LARGE TROPICAL UPPER
TROPOSPHERIC TROUGH CELL TO THE SOUTHEAST. THE 26/12Z 500MB ANALYSIS
INDICATES THAT THE SUBTROPICAL RIDGE (STR) EXTENDS WESTWARD ACROSS
WESTERN JAPAN INTO THE CHEJU-DO REGION WITH A DEEP MIDLATITUDE
SHORTWAVE TROUGH NOW POSITIONED ALONG EASTERN CHINA AND THE YELLOW
SEA.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY 16W IS TRACKING GENERALLY NORTH-NORTHWESTWARD ALONG THE
SOUTHWESTERN PERIPHERY OF THE STR WITH A MINOR TROCHOIDAL MOTION
(WOBBLE) EVIDENT. TY 16W IS EXPECTED TO CONTINUE TRACKING AROUND THE
WESTERN PERIPHERY OF THE STR AND INTO THE YELLOW SEA. DYNAMIC MODEL
GUIDANCE REMAINS IN TIGHT AGREEMENT WITH A 100 NM SPREAD WEST OF
SEOUL (NEAR TAU 36). THE JTWC FORECAST IS CONSISTENT WITH THE
PREVIOUS WARNINGS AND IS HEDGED EAST OF THE MODEL CONSENSUS. TY 16W
IS EXPECTED TO WEAKEN GRADUALLY THROUGH TAU 36, PARTIALLY AS A
RESULT OF THE ERC. HOWEVER, THE APPROACHING MID-LATITUDE
TROUGH MAY PROVIDE SOME ADDITIONAL OUTFLOW SUPPORT IN THE NEXT 24
HOURS, SOMEWHAT OFFSETTING THE EFFECTS OF THE ERC.  AFTER TAU 36,
THE SYSTEM WILL WEAKEN SIGNIFICANTLY DUE TO COOLER SST AND
INCREASING, STRONG VERTICAL WIND SHEAR ASSOCIATED WITH THE TROUGH.
TY 16W IS EXPECTED TO MAKE LANDFALL AFTER TAU 36 AND WILL BEGIN
EXTRA-TROPICAL TRANSITION (ETT) SHORTLY THEREAFTER. TY 16W IS
FORECAST TO COMPLETE ETT NEAR TAU 72 AND SHOULD REMAIN A GALE- FORCE
LOW AS IT TRACKS OVER MANCHURIA. BASED ON THE TIGHT
DYNAMIC MODEL GROUPING, THERE IS HIGH CONFIDENCE IN THE FORECAST
TRACK.//
NNNN
NNNN