Tropical Storm FAXAI Advisory Wed Sep 04

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (FOURTEEN) WARNING
NR 07//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 14W (FOURTEEN), LOCATED APPROXIMATELY 1601 NM
SOUTHEAST OF YOKOSUKA, JAPAN, HAS TRACKED WESTWARD AT 12 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS
A FULLY-EXPOSED, WELL-DEFINED LOW-LEVEL CIRCULATION CENTER WITH
LIMITED DEEP CONVECTION SHEARED OVER THE EASTERN SEMICIRCLE, WHICH
SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. A 030632Z MHS
89GHZ MICROWAVE IMAGE INDICATES TIGHTLY-CURVED SHALLOW BANDING
WRAPPING INTO THE CENTER WITH AN ISOLATED AREA OF DEEP CONVECTION
OVER THE SOUTHEAST QUADRANT. UPPER-LEVEL ANALYSIS INDICATES A
MARGINAL ENVIRONMENT WITH LOW TO MODERATE (15 TO 20 KNOTS) WESTERLY
VERTICAL WIND SHEAR AND FAIR POLEWARD OUTFLOW ASSOCIATED WITH A TUTT
CELL POSITIONED TO THE NORTH-NORTHWEST. TS 14W IS TRACKING WESTWARD
WHILE UNDER THE INFLUENCE OF A SUBTROPICAL RIDGE (STR), LOCATED TO
THE NORTHEAST.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. THE AFOREMENTIONED STR WILL REMAIN THE PRIMARY STEERING FEATURE
THROUGH TAU 72 AS TS 14W BEGINS TO TRACK WEST-NORTHWESTWARD. SEA
SURFACE TEMPERATURES WILL REMAIN FAVORABLE ALONG THE TRACK. UPPER
LEVEL OUTFLOW AND VERTICAL WIND SHEAR WILL GRADUALLY IMPROVE AND
ALLOW TS 14W TO SLOWLY INCREASE IN INTENSITY, REACHING 70 KNOTS BY
TAU 72. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT WITH A SPREAD OF
120 NM AT TAU 72. THEREFORE, THERE IS MODERATE CONFIDENCE IN THIS
PORTION OF THE JTWC FORECAST TRACK.
   C. BEYOND TAU 72, THE STR WILL SHIFT EASTWARD AND ALLOW TS 14W TO
BEGIN TO TRACK MORE NORTHWESTWARD. FAVORABLE SEA SURFACE TEMPERATURES
(29 TO 30 DEGREES CELSIUS), FAVORABLE VERTICAL WIND SHEAR AND AN
ENHANCED POLEWARD OUTFLOW CHANNEL WILL ALLOW TS 14W TO INCREASE TO AN
INTENSITY OF 90 KNOTS BY TAU 120. DYNAMIC MODEL GUIDANCE IS IN
FAIR AGREEMENT WITH A SPREAD OF 150 NM AT TAU 120. THE JTWC FORECAST
TRACK REMAINS SLIGHTLY TO THE WEST OF THE MULTI-MODEL CONSENSUS,
FAVORING THE ECMWF TRACK. OVERALL, THERE IS MODERATE CONFIDENCE IN
THIS PORTION OF THE JTWC FORECAST TRACK.//
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