Tropical Storm MEARI Advisory lun, 07-11

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 26W (MEARI) WARNING NR 16//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 26W (MEARI), LOCATED APPROXIMATELY 243 NM SOUTHEAST
OF IWO TO, JAPAN HAS TRACKED NORTHEASTWARD AT 15 KNOTS OVER THE PAST
SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS AN
ASYMMETRIC CONVECTIVE STRUCTURE AS THE SYSTEM HAS STARTED TO
ELONGATE TO THE NORTHEAST DUE TO THE STRONG SOUTHWESTERLY VERTICAL
WIND SHEAR ASSOCIATED WITH THE MID-LATITUDE WESTERLY FLOW. A 060856Z
GPM 89GHZ MICROWAVE IMAGE SHOWS A SMALL CONVECTIVE CORE THAT HAS
SLIGHTLY ERODED BUT STILL SURROUNDS A SMALL MICROWAVE EYE FEATURE.
THE CURRENT POSITION IS PLACED WITH FAIR CONFIDENCE UNDER THE
CENTRAL CONVECTION WITHIN THE CENTER OF A PARTIAL ASCAT PASS. THE
INTENSITY HAS BEEN HELD AT 90 KNOTS BASED ON DVORAK CURRENT
INTENSITY ESTIMATES THAT REMAIN AT T5.0 (90 KNOTS). A STRONG
POLEWARD OUTFLOW IS SUSTAINING THE CURRENT CONVECTION AND OFFSETTING
THE HIGH (25-30 KNOT) VERTICAL WIND SHEAR (VWS) THAT IS IN-PHASE
WITH THE STORM MOTION. TY 26W IS TRACKING NORTHEASTWARD ALONG THE
WESTERN PERIPHERY OF THE DEEP-LAYERED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY MEARI IS EXPECTED TO CONTINUE TRACKING NORTHEASTWARD TO
NORTH-NORTHEASTWARD THROUGHOUT THE FORECAST PERIOD ALONG THE WESTERN
PERIPHERY OF THE STEERING STR. TY 26W SHOULD MAINTAIN INTENSITY OVER
THE NEXT 12 HOURS BUT HAS MOST LIKELY REACHED ITS PEAK INTENSITY.
BEYOND TAU 12, INCREASING VWS ASSOCIATED WITH THE APPROACHING MID-
LATITUDE TROUGH WILL BEGIN THE RAPID WEAKENING PHASE. TY MEARI WILL
BEGIN EXTRA-TROPICAL TRANSITION (ETT) IN THE NEXT 24 HOURS AS IT
INTERACTS WITH THE BAROCLINIC ZONE AND EMBEDS UNDER THE MID-LATITUDE
WESTERLY FLOW. VWS ASSOCIATED WITH THE STRONG WESTERLIES WILL BECOME
INCREASINGLY UNFAVORABLE AS THE SYSTEM GAINS LATITUDE. THE TYPHOON
WILL GAIN FRONTAL CHARACTERISTICS AND COMPLETE ETT AS A STRONG COLD-
CORE LOW BY THE END OF THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE
REMAINS IN TIGHT AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN
THE JTWC TRACK FORECAST.//
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