WDPN31 PGTW 071500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W WARNING NR 08//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 10W (MANGKHUT), LOCATED APPROXIMATELY 92 NM
SOUTH OF HANOI, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 13 KNOTS
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS
THE DEEP CONVECTIVE BANDS ASSOCIATED WITH THE SYSTEM HAVE COLLAPSED
AS THEY BEGAN TO INTERACT WITH THE TOPOGRAPHY OF VIETNAM. THE INITIAL
POSITION IS BASED ON A CLOSED LOW LEVEL REFLECTIVITY SIGNATURE ON A
071055Z 37 GHZ SSMI/S MICROWAVE IMAGE WITH HIGH CONFIDENCE. THE
INITIAL INTENSITY IS BASED ON CONGRUENT DVORAK ESTIMATES FROM PGTW
AND RJTD. THE SYSTEM IS SOUTH OF THE RIDGE AXIS IN AN AREA OF
MODERATE (20 KNOT) NORTHEASTERLY VERTICAL WIND SHEAR (VWS). THE
CYCLONE IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF THE SUBTROPICAL
RIDGE TO THE NORTH.
3. FORECAST REASONING.
   A. NO CHANGE TO THE PREVIOUS FORECAST PHILOSOPHY.
   B. TS MANGKHUT IS POISED TO MAKE LANDFALL APPROXIMATELY 65 NM
SOUTH OF HANOI OVER THE NEXT FEW HOURS. THE SYSTEM WILL RAPIDLY
WEAKEN AS VWS AND LAND INTERACTION TAKE THEIR TOLL, LEADING TO
DISSIPATION BY TAU 24. DYNAMIC MODEL GUIDANCE AND ENSEMBLE DATA ARE
IN VERY TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE CURRENT JTWC
FORECAST.   //
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