Tropical Storm LINGLING Advisory Tue Sep 03

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (LINGLING) WARNING
NR 05//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 15W (LINGLING), LOCATED APPROXIMATELY 451 NM
SOUTH-SOUTHWEST OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD AT 09
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS IMPRESSIVE DEEP CONVECTIVE BANDING WRAPPING AROUND THE
LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED
WITH HIGH CONFIDENCE AND IS BASED ON A 022255Z SSMIS 37GHZ MICROWAVE
IMAGE, WHICH SHOWS A WELL DEFINED CIRCULATION. THE INITIAL INTENSITY
OF 50 KNOTS IS HEDGED BETWEEN DVORAK CURRENT INTENSITY (CI) ESTIMATES
OF T3.0 (45 KNOTS) FROM RJTD AND T3.5 (55 KNOTS) FROM PGTW.
ENVIRONMENTAL ANALYSIS SHOWS TS 15W IS EXPERIENCING FAVORABLE (5 TO
10 KNOT) VERTICAL WIND SHEAR. THERE IS A STRONG EQUATORWARD OUTFLOW
CHANNEL, WHILE THE POLEWARD OUTFLOW CHANNEL CONTINUES TO DEVELOP. SEA
SURFACE TEMPERATURES ARE FAVORABLE FOR ADDITIONAL DEVELOPMENT, NEAR
30 DEGREES CELSIUS. TS 15W IS TRACKING NORTHWARD WHILE UNDER THE
INFLUENCE OF A SUBTROPICAL RIDGE (STR), LOCATED TO THE EAST.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. THE STR LOCATED TO THE EAST WILL BE THE PRIMARY STEERING
FEATURE FOR TS 15W THROUGH TAU 72. FAVORABLE SEA SURFACE TEMPERATURES
AND FAVORABLE VERTICAL WIND SHEAR WILL ALLOW TS 15W TO QUICKLY
INTENSIFY, REACHING 85 KNOTS BY TAU 72. DYNAMIC MODEL GUIDANCE IS IN
AGREEMENT THAT TS 15W WILL TRACK NORTHWARD TO NORTH-NORTHEASTWARD
THROUGH TAU 36 AND THEN TRACK NORTHWARD. DYNAMIC MODEL GUIDANCE HAS
COME INTO SLIGHTLY BETTER AGREEMENT SINCE THE LAST MODEL RUN BUT
OVERALL AGREEMENT REMAINS POOR. NAVGEM IS AN OUTLIER TO THE WEST BY
TAU 72. ADDITIONALLY, GFS AND THE GFS ENSEMBLE STILL INDICATE A
SLOWER TRACK SPEED. THE MODEL SPREAD BY TAU 72 IS 200 NM. THE JTWC
FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH LOW
CONFIDENCE.
   C. IN THE LONG TERM, TS 15W WILL CONTINUE TO TRACK NORTHWARD WHILE
POSITIONED ALONG THE WESTERN EDGE OF THE STR. AN APPROACHING WEST TO
EAST MOVING SHORTWAVE TROUGH WILL HELP TO ACCELERATE TS 15W
NORTHWARD. AS TS 15W TRACKS NORTHWARD IT WILL BEGIN EXTRATROPICAL
TRANSITION (ETT) BY TAU 96 AND COMPLETE ETT BY TAU 120. DYNAMIC MODEL
GUIDANCE HAS BOTH A LARGE ALONG-TRACK AND CROSS-TRACK DISAGREEMENT
WITH A SPREAD OF 400 NM. THE JTWC FORECAST TRACK IS PLACED SLIGHTLY
TO THE WEST OF THE MULTI-MODEL CONSENSUS WITH LOW CONFIDENCE.//
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