Tropical Storm EWINIAR Advisory Fri Sep 28

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (EWINIAR) WARNING
NR 17//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 19W (EWINIAR), LOCATED APPROXIMATELY 260 NM
SOUTH-SOUTHEAST OF TOKYO, JAPAN, HAS TRACKED NORTHEASTWARD AT 05
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL (MSI)
SATELLITE IMAGERY DEPICTS A SYMMETRIC LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH DEEP CONVECTIVE BANDING WRAPPING AROUND THE CENTER. A
272330Z SSMIS 91 GHZ MICROWAVE IMAGE REVEALED A VERY TIGHTLY WRAPPED
SYSTEM WITH ONLY ONE SMALL AREA OF CONVECTIVE BANDING IN THE EASTERN
SEMI-CIRCLE. A 271900Z AMSU CROSS-SECTION SHOWS A SLIGHTLY WARMER
+4C TEMPERATURE ANOMALY. THERE IS GOOD CONFIDENCE IN THE INITIAL
POSITION BASED ON THE MSI AND MICROWAVE IMAGERY. THE INITIAL
INTENSITY IS ASSESSED AT 45 KNOTS BASED ON OVERALL STORM STRUCTURE
AND THE DVORAK CURRENT INTENSITY ESTIMATES OF 45 KNOTS FROM PGTW.
UPPER-LEVEL ANALYSIS REVEALS TS 19W IS IN AN AREA OF MODERATE (10-15
KNOT) VERTICAL WIND SHEAR AND HAS SOME POLEWARD OUTFLOW INTO THE
WESTERLIES TO THE NORTH.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS 19W IS FORECAST TO PICK UP SPEED AND TURN INCREASINGLY
NORTHEASTWARD AS IT TRACKS ALONG THE NORTHWESTERN PERIPHERY OF THE
STR AND WILL ACCELERATE AS AN APPROACHING MIDLATITUDE TROUGH,
CURRENTLY LOCATED OVER EASTERN CHINA AND THE KOREA REGION, TRACKS
EASTWARD OVER JAPAN. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT
WITH EGRR TAKING A VERY ERRONEOUS TRACK TO THE NORTH AND NORTHWEST
IN THE LATER TAUS. THE JTWC FORECAST IS POSITIONED RIGHT AND FASTER
THAN THE MULTI-MODEL CONSENSUS, TO OFFSET THE EGRR TRACK AND FAVOR
THE ECMWF, GFS AND JGSM MODELS. TS 19W IS EXPECTED TO WEAKEN
GRADUALLY AND SHOULD BEGIN EXTRA-TROPICAL TRANSITION (ETT) AFTER TAU
48 AND COMPLETE ETT BY TAU 72.//
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