WDPN31 PGTW 071500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 11W (HALONG) WARNING NR 41//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 11W (HALONG), LOCATED APPROXIMATELY 480 NM SOUTH OF
IWAKUNI, JAPAN, HAS TRACKED NORTHWARD AT 05 KNOTS OVER THE PAST
SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY INDICATES 
LITTLE CHANGE IN STRUCTURE OVER THE PAST SIX HOURS. TY 11W HAS 
MAINTAINED A LARGE 35 NM EYE WITH THE BULK OF THE DEEP CONVECTION 
OVER THE SOUTHERN SEMI-CIRCLE. A 071056Z SSMIS IMAGE REVEALS A 
COMPLETE EYEWALL WITH TIGHTLY-CURVED BANDING WRAPPING INTO LOW-LEVEL 
CIRCULATION CENTER. AS PREVIOUSLY DISCUSSED, MAXIMUM SUSTAINED 
SURFACE WINDS AT MINAMIDAITO AND KITADAITO ISLANDS WERE 
APPROXIMATELY 65 KNOTS (32.1 M/S) WITH A MINIMUM SLP OF 954 MB. THE 
CURRENT INTENSITY REMAINS ASSESSED AT 75 KNOTS BASED ON THE SURFACE 
OBSERVATIONS AND DVORAK INTENSITY ESTIMATES RANGING FROM T4.0 (65 
KNOTS) TO T4.5 (77 KNOTS). ANIMATED WATER VAPOR IMAGERY INDICATES 
NEAR-RADIAL OUTFLOW AIDED BY AN UPPER-LOW POSITIONED NEAR TOKYO. TY 
11W IS TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF THE POLEWARD-
ORIENTED SUBTROPICAL RIDGE (STR) POSITIONED SOUTH OF CENTRAL JAPAN. 
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING.
   B. TY 11W IS FORECAST TO TRACK GENERALLY NORTHWARD THROUGH TAU 36 
ALONG THE WESTERN PERIPHERY OF THE STR. AFTER TAU 36, THE STR IS 
FORECAST TO BUILD OVER THE EAST SEA AND RE-ORIENT AS A MIDLATITUDE 
SHORTWAVE TROUGH DIGS OVER THE KOREAN PENINSULA AND WESTERN JAPAN, 
WHICH SHOULD ALLOW THE SYSTEM TO ACCELERATE NORTH-NORTHEASTWARD AND 
BEGIN EXTRA-TROPICAL TRANSITION (ETT). TY 11W IS FORECAST TO 
MAINTAIN INTENSITY AT 75 KNOTS UNTIL TAU 24 AFTERWHICH THE SYSTEM 
SHOULD RE-INTENSIFY AS POLEWARD OUTFLOW IMPROVES. TY 11W WILL MAKE 
LANDFALL AFTER TAU 48 AND IS FORECAST TO WEAKEN SIGNIFICANTLY DUE TO 
THE ROUGH TERRAIN OVER WESTERN JAPAN. AS THE SYSTEM EMERGES OVER THE 
EAST SEA, IT WILL CONTINUE TO WEAKEN DUE TO COOLER SST AND 
INCREASING VERTICAL WIND SHEAR. DYNAMIC MODEL GUIDANCE IS IN GOOD 
AGREEMENT, THEREFORE, THE JTWC FORECAST IS POSITIONED CLOSE TO THE 
MULTI-MODEL CONSENSUS.
   C. IN THE EXTENDED TAUS, TY 11W WILL ACCELERATE NORTH-
NORTHEASTWARD AND IS FORECAST TO COMPLETE ETT BY TAU 96. BASED ON 
THE TIGHT MODEL AGREEMENT, THERE IS OVERALL HIGH CONFIDENCE IN THE 
JTWC FORECAST TRACK.//
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