Tropical Storm KUJIRA Advisory Mon Sep 28

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 15W (KUJIRI)
WARNING NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 15W (KUJIRA), LOCATED APPROXIMATELY 254
NM SOUTHEAST OF MINAMI TORI SHIMA, HAS TRACKED NORTHWESTWARD AT 15
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH EXTENSIVE DEEP CONVECTIVE BANDING OVER THE SOUTHERN AND
EASTERN SEMICIRCLES. A 270729Z SSMIS COMPOSITE MICROWAVE IMAGE
INDICATES A BROAD LLCC WITH FRAGMENTED BANDING WRAPPING INTO THE
NORTH QUADRANT OF THE SYSTEM. OVERALL, THERE IS FAIR CONFIDENCE IN
THE INITIAL POSITION. THE INITIAL INTENSITY REMAINS ASSESSED AT 30
KNOTS BASED ON PGTW/KNES DVORAK ESTIMATES OF T2.0 (30 KNOTS). UPPER-
LEVEL ANALYSIS CONTINUES TO REVEAL A MARGINALLY-FAVORABLE
ENVIRONMENT WITH A BROAD, CONVERGENT UPPER LOW POSITIONED OVER THE
CENTER, WHICH CONTINUES TO HAMPER DEVELOPMENT, OFFSET BY ROBUST
EQUATORWARD OUTFLOW AND DIFFLUENT POLEWARD OUTFLOW. SST VALUES (29C)
REMAIN CONDUCIVE FOR FURTHER DEVELOPMENT. TD 15W IS TRACKING
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF A SUBTROPICAL
RIDGE (STR) POSITIONED TO THE NORTHEAST.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TD 15W IS FORECAST TO TRACK NORTH-NORTHWESTWARD THROUGH TAU 24
WITH STEADY INTENSIFICATION. AFTER TAU 24, TD 15W WILL BEGIN TO
ROUND THE STR WITH FURTHER INTENSIFICATION DUE TO IMPROVING POLEWARD
OUTFLOW ASSOCIATED WITH A MAJOR SHORTWAVE TROUGH DIGGING SOUTH OF
JAPAN. THE SYSTEM IS EXPECTED TO PEAK AT 70 KNOTS BY TAU 48. TD 15W
IS FORECAST TO BEGIN EXTRA-TROPICAL TRANSITION (ETT) AS IT RECURVES
INTO THE MIDLATITUDE WESTERLIES NEAR TAU 60. NUMERICAL MODEL
GUIDANCE REMAINS IN TIGHT AGREEMENT THROUGH TAU 72 WITH A SPREAD OF
80NM AT TAU 72.
   C. AFTER TAU 72, TD 15W WILL WEAKEN AS IT ENCOUNTERS INCREASING
VERTICAL WIND SHEAR (30-55 KNOTS) AND TRACKS OVER COOL SST VALUES
(22-20C). TD 15W WILL COMPLETE ETT NEAR TAU 84 AS IT GAINS FRONTAL
CHARACTERISTICS AND BECOMES EMBEDDED WITHIN THE MIDLATITUDE
WESTERLIES. NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT
THROUGH THE FORECAST PERIOD, LENDING HIGH CONFIDENCE IN THE JTWC
FORECAST TRACK.//
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