WDPN31 PGTW 300300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (KONG-REY) WARNING 
NR 17//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM 14W (KONG-REY), LOCATED APPROXIMATELY 410 NM 
SOUTHWEST OF SASEBO, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 15 
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY (MSI) REVEALS THE LOW LEVEL CIRCULATION CENTER (LLCC) HAS 
BECOME FULLY EXPOSED AND HAS STARTED TO ELONGATE ALONG THE NORTHEAST-
SOUTHWEST AXIS OVER THE PAST FEW HOURS. TRACK SPEEDS HAVE STARTED TO 
INCREASE OVER THE LAST SIX HOURS AS TS 14W HAS ROUNDED THE 
SUBTROPICAL RIDGE (STR) AXIS AND IS BEGINNING TO INTERACT WITH THE 
BAROCLINIC BOUNDARY TO THE NORTHWEST. THE CURRENT POSITION IS BASED 
ON THE WELL-DEFINED CENTER VISIBLE IN MSI. INTENSITY HAS BEEN 
DECREASED AS THE DEEP CONVECTION THAT HAD PREVIOUSLY BEEN BUILDING 
FROM THE SOUTHWEST HAS DISSIPATED. DVORAK ESTIMATES FROM PGTW, KNES 
AND RJTD ALL SUPPORT THE OBSERVED WEAKENING TREND. UPPER LEVEL 
ANALYSIS INDICATES THE VERTICAL WIND SHEAR (VWS) OVER THE SYSTEM 
REMAINS MODERATE (10 TO 15 KNOTS). IT APPEARS THAT TS 14W HAS 
STARTED THE INITIAL PHASE OF EXTRA-TROPICAL TRANSITION IN THE PAST 
FEW HOURS.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO FORECAST PHILOSOPHY FROM THE PREVIOUS 
PROGNOSTIC REASONING BULLETIN. 
   B. TS 14W IS EXPECTED TO CONTINUE TURNING TO THE NORTHEAST ALONG 
THE NORTHWESTERN QUADRANT OF THE STR AND ACCELERATING IN THE NEXT 
SIX TO TWELVE HOURS AS THE APPROACHING MID-LATITUDE TROUGH ENHANCES 
GRADIENT FLOW TOWARDS KYUSHU. AS THE SYSTEM MOVES TO THE NORTHEAST, 
INCREASING INTERACTION WITH THE MID-LATITUDE UPPER LEVEL WESTERLY 
FLOW WILL BRIEFLY ENHANCE THE POLEWARD OUTFLOW CHANNEL, ALLOWING FOR 
AN INCREASE IN VENTILATION AND THE SLIGHT INTENSIFICATION FROM TAU 
12 TO 24. THIS WILL BE OFFSET BY INCREASING DRIER CONTINENTAL AIR 
ENTRAINMENT IN THE LOW- TO MID-LEVELS BEYOND TAU 24. THIS INCREASED 
INTERACTION WITH THE BAROCLINIC ZONE WILL ACCELERATE THE EXTRA-
TROPICAL TRANSITION PROCESS WITH FULL TRANSITION EXPECTED BY TAU 24. 
BEYOND TAU 24 THE CONTINUAL INTERACTION WITH THE BAROCLINIC ZONE AND 
THE INTERACTION OF THE LLCC WITH LAND WILL LEAD TO AN EXPANSION OF 
THE LLCC AND THE RAPID WEAKENING OF THE SYSTEM. THE REMNANTS OF THE 
LLCC ARE EXPECTED TO BRIEFLY TRACK INTO THE EASTERN EXTENT OF THE 
SEA OF JAPAN BEFORE MOVING OVER NORTHERN HONSHU TOWARDS THE 
NORTHWESTERN PACIFIC. MODEL GUIDANCE REMAINS IN FAIR AGREEMENT AS 
THE SYSTEM STARTS TO TURN TO THE NORTHEAST. BASED ON THE IMPROVED 
STEERING ENVIRONMENT AROUND THE NORTHWESTERN QUADRANT OF THE STR, 
CONFIDENCE IN THE FORECAST TRACK HAS SHIFTED TO HIGH.//
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