WDPN32 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 18W (PHANFONE) WARNING NR 28//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 18W (PHANFONE), LOCATED APPROXIMATELY 405 NM
SOUTHWEST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHEASTWARD AT 16 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
(MSI) SHOWS A 25-NM RAGGED EYE WITH TIGHT SPIRAL BANDING EVEN AS THE
CONVECTION HAS BECOME MORE SHALLOW AND SHEARED. THE INITIAL POSITION
IS BASED ON THE EYE FEATURE ON THE EIR LOOP WITH HIGH CONFIDENCE. THE
INITIAL INTENSITY OF 90 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF
DVORAK CURRENT INTENSITY ESTIMATES FROM ALL REPORTING AGENCIES.
UPPER-LEVEL ANALYSIS INDICATES TY 18W IS LOCATED IN AN AREA OF STRONG
(GREATER THAN 40 KNOTS) VERTICAL WIND SHEAR (VWS) OFFSET BY VIGOROUS
OUTFLOW, ESPECIALLY ON THE POLEWARD SIDE THAT IS SUSTAINING THE REMNANT
CONVECTION. TY 18W HAS ROUNDED THE WESTERN EDGE OF THE DEEP-LAYERED
SUBTROPICAL RIDGE (STR) TO THE EAST AND IS NOW UNDERGOING
EXTRA-TROPICAL TRANSITION (ETT) AS IT ACCELERATES NORTHEASTWARD.
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM 
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY 18W WILL BE QUICKLY ABSORBED INTO THE BAROCLINIC ZONE AS IT
COMPLETES ETT. INCREASING VWS AND COOLING SEA SURFACE TEMPERATURES
WILL RAPIDLY ERODE THE SYSTEM BUT WILL STILL BE A VERY INTENSE STORM
FORCE COLD-CORE LOW BY TAU 24. THE AVAILABLE NUMERIC GUIDANCE REMAINS
IN TIGHT AGREEMENT LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST
THAT IS LAID SLIGHTLY TO THE RIGHT OF AND FASTER THAN MULTI-MODEL
CONSENSUS.//
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