WDPN32 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
RMKS/
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 30W (KONG-REY) WARNING 
NR 31//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 30W (KONG-REY), LOCATED APPROXIMATELY 206 NM 
WEST-SOUTHWEST OF SASEBO, JAPAN, HAS TRACKED NORTHWARD AT 19 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE 
IMAGERY DEPICTS SHALLOW BANDING WRAPPING INTO AN OBSCURED LOW LEVEL 
CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION LIMITED TO A SMALL 
AREA JUST NORTHWEST OF THE LLCC AND AN ASYMMETRIC CLOUD PATTERN 
EXTENDING PRIMARILY TO THE NORTH. THE INITIAL POSITION IS PLACED 
WITH FAIR CONFIDENCE BASED ON THE ANIMATED EIR AND IS SUPPORTED BY A 
051010Z SSMI/S 89 GHZ IMAGE. THE INITIAL INTENSITY OF 55 KNOTS IS 
CONSISTENT WITH DVORAK CURRENT INTENSITY ESTIMATES OF T3.5 (55 
KNOTS) FROM PGTW AND RJTD. UPPER LEVEL ANALYSIS INDICATES TS 30W IS 
BEING AFFECTED BY A MID-LATITUDE TROUGH TO THE NORTHWEST. AS A 
RESULT, EXCELLENT POLEWARD OUTFLOW IS BEING OFFSET BY HIGH (20-30 
KNOT) VERTICAL WIND SHEAR (VWS). SEA SURFACE TEMPERATURES (26-27 
CELSIUS) ARE MARGINAL. THE CYCLONE IS TRACKING ALONG THE WEST-
NORTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE 
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS 30W HAS RECENTLY CRESTED THE STR AXIS AND WILL BEGIN 
ACCELERATING NORTHEASTWARD AHEAD OF THE APPROACHING MID-LATITUDE 
TROUGH. BY TAU 12, TS 30W WILL BEGIN EXTRATROPICAL TRANSITION (ETT) 
AND IT WILL COMPLETE ETT SOMETIME AROUND TAU 36. DESPITE HIGH VWS 
VALUES, WIND SPEEDS WILL NOT DECREASE SIGNIFICANTLY AND INTENSITY IS 
EXPECTED TO BE 45 KNOTS OR GREATER AS IT DEVELOPS INTO A COLD-CORE 
LOW. THE JTWC TRACK FORECAST IS PLACED VERY CLOSE TO THE PRIOR 
FORECAST TRACK THROUGH TAU 24 BUT THE TRACK IS MORE EASTWARD, 
CONSISTENT WITH THE MULTI-MODEL CONSENSUS, THROUGH TAU 48. BY TAU 
48, MODEL SPREAD IS 132 NM, LENDING FAIR CONFIDENCE TO THE JTWC 
TRACK FORECAST.//
NNNN