Tropical Storm BOLAVEN Advisory Fri Aug 24

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (BOLAVEN) WARNING NR 19//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 16W (BOLAVEN), LOCATED APPROXIMATELY 380 NM SOUTHEAST OF
KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 05
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY (EIR) SHOWS A WELL DEFINED EYE WITH DEEP CONVECTIVE BANDING
WRAPPING INTO THE LOW LEVEL CIRCULATION CENTER (LLCC) FORMING A WELL
DEFINED EYEWALL. THE SYMMETRIC TIGHTLY CURVED BANDING FEATURES HAVE
BEEN RADIALLY EXPANDING OVER THE PAST SIX HOURS, WITH THE EYE
BECOMING MORE PRONOUNCED. THERE IS AN APPARENT WOBBLE OF THE EYE
WITHIN THE EIR. THE CURRENT INTENSITY OF 120 KNOTS IS BASED ON THE
NOTED IMPROVEMENT AND IS ON THE HIGH SIDE OF DVORAK ESTIMATES FROM
PGTW, KNES, AND RJTD RANGING FROM 102 TO 127 KNOTS. UPPER LEVEL
ANALYSIS CONTINUES TO INDICATE THE MESOSCALE ANTICYCLONE IS
PROVIDING VERY FAVORABLE RADIAL OUTFLOW MOST NOTABLY IN THE
EQUATORWARD OUTFLOW CHANNEL. TY 16W CONTINUES TO TRACK ALONG THE
SOUTHWESTERN PERIPHERY OF THE DEEP LAYERED SUBTROPICAL RIDGE (STR)
TO THE NORTH, ANCHORED JUST EAST OF HONSHU, JAPAN.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY 16W WILL CONTINUE TO TRACK ALONG THE SOUTHWESTERN PERIMETER
OF THE STR THROUGH TAU 72. VERY FAVORABLE CONDITIONS WILL PERSIST
ALLOWING FOR TY 16W TO INTENSIFY TO SUPER TYPHOON INTENSITY WITHIN
THE NEXT 24 TO 36 HOURS. BETWEEN TAU 36 AND 72 DECREASING OCEAN HEAT
CONTENT WILL WEAKEN THE SYSTEM BUT WILL BE OFFSET FOR A SHORT PERIOD
OF INCREASED POLEWARD OUTFLOW FROM AN APPROACHING DEEP LONGWAVE
TROUGH.
   C. AFTER TAU 72, TY 16W SHOULD TRACK NORTHWARD INTO THE WEAKNESS
CAUSED BY THE PREVIOUSLY MENTIONED TROUGH. TRACK SPEEDS WILL
ACCELERATE DURING THIS TIME AND INTENSITY WILL BE ON THE DECLINE AS
OCEAN PARAMETERS BECOME LESS FAVORABLE AND WESTERLY VERTICAL WIND
SHEAR INCREASES TO STRONG LEVELS. EXTRA-TROPICAL TRANSITION IS
EXPECTED TO BEGIN PRIOR TO TY 16W MAKING LANDFALL ALONG THE WESTERN
COAST OF NORTH KOREA AROUND TAU 96. ALTHOUGH THE SYSTEM WILL STILL
BE AT TYPHOON STRENGTH AROUND TAU 96, INCREASING MID-LATITUDE
ADVECTION OF COOLER, DRIER CONTINENTAL AIR INTO THE SYSTEM WILL
BEGIN THE EXTRATROPICAL TRANSITION PROCESS. THE SYSTEM IS EXPECTED
TO BE COMPLETELY EXTRATROPICAL BY TAU 120 AS IT IS ABSORBED WITHIN
THE LONGWAVE TROUGHING. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT
THROUGH TAU 120, AND BASED ON THE TIGHT GROUPING OF MODEL GUIDANCE
THERE IS HIGH CONFIDENCE IN THE TRACK FORECAST CURVING OVER NORTHERN
KOREA.//
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