WDPN31 PGTW 090300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 11W (HALONG) WARNING NR 47//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 11W (HALONG), LOCATED APPROXIMATELY 216 NM SOUTHEAST OF
SASEBO, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 09 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) 
SATELLITE IMAGERY DEPICTS GOOD CONVECTIVE BANDING WRAPPING INTO A 
FAIRLY BROAD CENTER. A 081740Z AMSU-B IMAGE SHOWS ERODING CENTRAL 
CONVECTION, WITH SOME BANDING OVER THE EASTERN HALF AND NORTHERN 
SEMI-CIRCLE. THERE IS GOOD CONFIDENCE IN THE CURRENT POSITION BASED 
ON THE EIR IMAGERY AND AMSU-B IMAGE. ANIMATED WATER VAPOR IMAGERY 
INDICATES SOME POLEWARD OUTFLOW ASSOCIATED WITH THE  MIDLATITUDE 
WESTERLIES THROUGH THE SEA OF JAPAN. THE INITIAL INTENSITY IS 
MAINTAINED AT 70 KNOTS BASED ON THE ESTIMATED DVORAK CURRENT 
INTENSITIES FROM RJTD AND PGTW. TY 11W CONTINUES TO TRACK NORTH 
ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE 
EAST.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING.
   B. TY HALONG 11W IS EXPECTED TO CONTINUE TO TRACK NORTH-
NORTHEASTWARD THROUGH THE FORECAST PERIOD ALONG THE STR AND IS 
EXPECTED TO MAINTAIN ITS INTENSITY THROUGH THE NEXT 12 HOURS. WHILE 
THERE IS SLIGHT POLEWARD OUTFLOW, THE VERTICAL WIND SHEAR AND DRY 
CONTINENTAL AIR TO THE EAST WILL COUNTERACT ANY POTENTIAL INCREASE 
IN INTENSITY. THE SYSTEM WILL WEAKEN RAPIDLY AS IT MAKES LANDFALL IN 
CENTRAL SHIKOKU BY TAU 24 AND WILL BEGIN EXTRA-TROPICAL TRANSITION 
(ETT). TY 11W STARTS TO BECOME EMBEDDED IN THE MIDLATITUDE SHORTWAVE 
TROUGH, COMPLETING ETT BY TAU 48 AS HALONG GAINS COLD CORE 
CHARACTERISTICS. MODEL GUIDANCE CONTINUES TO REMAIN IN GOOD 
AGREEMENT, LEADING TO HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.//
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