WDPN32 PGTW 221500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (MEARI)//
/WARNING NR 04//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. ANIMATED WATER VAPOR IMAGERY SHOWS A VERY BROAD SYSTEM THAT
SPANS ALMOST THE ENTIRE PHILIPPINE SEA. DEEP CONVECTIVE BANDS ARE 
CONSOLIDATING AROUND TWO POSSIBLE LOW LEVEL CIRCULATION CENTERS
(LLCC). THIS FORECAST IS BASED ON THE MORE DOMINANT LLCC WITH
FORMATIVE BANDS WRAPPING FROM THE NORTH. THE SECONDARY LLCC IS TO
THE SOUTHEAST WITH FORMATIVE BANDS WRAPPING FROM THE SOUTHWEST.
UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS UNDER A RIDGE AXIS IN
AN AREA OF LIGHT TO MODERATE VERTICAL WIND SHEAR. A TROPICAL 
UPPER TROPOSPHERIC TROUGH CELL TO THE EAST IS ENHANCING OUTFLOW. 
THE INITIAL POSITION IS BASED ON A 221135Z SSMI-S MICROWAVE 
IMAGE SHOWING A DISTINCT NOTCH OVER THE LLCC. THE INITIAL INTENSITY 
IS SUPPORTED BY DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD. THE 
SYSTEM IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A DEEP-LAYERED 
SUBTROPICAL RIDGE ANCHORED SOUTHEAST OF JAPAN. 
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY.
   B. TS 07W IS EXPECTED TO CONTINUE TRACKING NORHTWESTWARD UP TO
TAU 48 THEN MOVE ON A MORE POLEWARD TRACK IN RESPONSE TO A MID-
LATITUDE TROUGH APPROACHING FROM THE NORTHWEST. THE SYSTEM WILL
GRADUALLY INTENSIFY DUE TO THE FAVORABLE UPPER LEVEL CONDITIONS,
PEAKING AT TYPHOON INTENSITY BEFORE TAIWAN. IT WILL THEN CROSS THE
TAIWAN STRAIT AND MAKE LANDFALL OVER EASTERN TIP OF CHINA BY TAU 72. 
   C. IN THE EXTENDED FORECAST, TS MEARI WILL EXIT INTO THE YELLOW
SEA NEAR SHANGHAI, ACCELERATE, AND COMMENCE DISSIPATION OVER WATER.
THIS IS DUE TO INCREASED VERTICAL WIND SHEAR ASSOCIATED WITH THE
SUBTROPICAL JET AND COOLER SEA SURFACE TEMPERATURE. THE AVAILABLE
NUMERICAL GUIDANCE FAN OUT TO ABOUT A 30-DEGREE SPREAD WITH ECMWF TO
THE LEFT OF AND NOGAPS AND GFDN TO THE RIGHT OF THE MODEL ENVELOPE.
THIS TRACK FORECAST IS TO THE LEFT OF CONSENSUS TO OFFSET THE RIGHT
OUTLIERS' UNLIKELY INCURSION INTO THE STEERING RIDGE.//
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