Tropical Storm TALIM Advisory Thu Sep 14

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (TALIM) WARNING NR 19//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 20W (TALIM), LOCATED APPROXIMATELY 145 NM SOUTHWEST OF
KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWESTWARD AT 08 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS
DEEP CONVECTION WRAPPING INTO A RAGGED 28-NM EYE. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE. THE
INITIAL INTENSITY OF 75 KNOTS IS BASED ON DVORAK ESTIMATES OF T4.5
(77 KNOTS) FROM PGTW AND RJTD. ENVIRONMENTAL ANALYSIS INDICATES THE
SYSTEM IS IN AN AREA OF LOW (5-10 KNOT) VERTICAL WIND SHEAR (VWS) AND
IS TRACKING THROUGH VERY WARM (30-31 CELSIUS) SEA SURFACE
TEMPERATURES (SSTS). TYPHOON TALIM CURRENTLY HAS A STRONG POLEWARD
AND EQUATORWARD OUTFLOW. THE POLEWARD OUTFLOW IS BEING ENHANCED BY A
MID-LATITUDE TROUGH TRANSITING NORTH OF THE SYSTEM AND THE
EQUATORWARD OUTFLOW IS ENHANCED BY A TUTT CELL TO THE SOUTHEAST. THE
CYCLONE IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) LOCATED TO THE NORTHEAST.
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY 20W WILL CONTINUE TRACKING NORTHWESTWARD UNDER THE INFLUENCE
OF THE STEERING STR THROUGH TAU 24. AFTERWARD, THE SYSTEM WILL BEGIN
TO ROUND THE WESTERN EDGE OF THE STR AND TRACK TO THE NORTHEAST.
PERSISTENT FAVORABLE ENVIRONMENTAL CONDITIONS AND THE ENHANCED
OUTFLOW CONDITIONS WILL ALLOW FOR A PERIOD OF RAPID INTENSIFICATION,
PEAKING AT 110 KNOTS BY TAU 48. AFTER TAU 48, THE SYSTEM WILL
GRADUALLY WEAKEN DUE TO INCREASING VWS. DYNAMIC MODEL GUIDANCE IS IN
GOOD AGREEMENT THROUGH TAU 72, LENDING FAIR CONFIDENCE IN THIS
PORTION OF THE JTWC TRACK FORECAST.
   C. AFTER TAU 72, TY TALIM WILL ACCELERATE NORTHEASTWARD AS IT GETS
EMBEDDED IN THE MID-LATITUDE TROUGH. THE SYSTEM IS FORECAST TO MAKE
LANDFALL OVER SOUTHERN KYUSHU SHORTLY AFTER TAU 72 AND TRACK ACROSS
AND INTO HONSHU. INCREASING VWS AND INTERACTION WITH TERRAIN WILL
GRADUALLY WEAKEN THE SYSTEM. AFTER LANDFALL, TALIM IS FORECAST TO
BEGIN EXTRA-TROPICAL TRANSITION. AS THE SYSTEM TRACKS ACROSS SOUTHERN
JAPAN, HIGH VWS, INTERACTION WITH THE MID-LATITUDE TROUGH, AND
OVERLAND FRICTIONAL EFFECTS WILL FURTHER WEAKEN THE SYSTEM. THERE IS
A SIGNIFICANT SPREAD IN THE AVAILABLE MODEL GUIDANCE AFTER TAU 72,
LENDING LOW CONFIDENCE IN THIS PORTION OF THE JTWC TRACK FORECAST.//
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