Tropical Storm GONI Advisory 23 Αυγ.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (GONI) WARNING NR 36//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 16W (GONI), LOCATED APPROXIMATELY 356 NM SOUTHWEST OF
KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 09
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS TIGHTLY CURVED BANDING WRAPPING INTO A PINHOLE EYE
FEATURE THAT HAS FILLED OVER THE PAST FEW HOURS. A 221719Z GCOM 37
GHZ COLOR IMAGE REVEALS THE TIGHT SPIRAL STRUCTURE OF THE CONVECTIVE
CORE. THE INITIAL POSITION IS BASED ON RADAR COMPOSITE IMAGERY, GOOD
AGENCY FIX AGREEMENT, AND THE AFOREMENTIONED MICROWAVE DATA WITH
HIGH CONFIDENCE. THE INITIAL INTENSITY
OF 80 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF DVORAK ESTIMATES
FROM ALL REPORTING AGENCIES. UPPER LEVEL ANALYSIS INDICATES A
FAVORABLE ENVIRONMENT WITH LIGHT (5 TO 10 KNOT) NORTHERLY VERTICAL
WIND SHEAR (VWS) AND GOOD RADIAL OUTFLOW. TY 16W IS TRACKING UNDER
THE STEERING
INFLUENCE OF A BUILDING NEAR-EQUATORIAL RIDGE (NER) TO THE SOUTHEAST.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE, HOWEVER, THE TRACK 48-72 HOUR TRACK
POSITION WAS SHIFTED SLIGHTLY WESTWARD, RESULTING IN A CHANGE TO THE
SASEBO CPA DISTANCE.
   B. TY 16W WILL CONTINUE TO MOVE NORTH-NORTHEASTWARD AS NEAR
EQUATORIAL RIDGING TO THE EAST BUILDS INTO A HIGHLY MERIDIONAL
PATTERN, AND EVENTUALLY BECOMES SUBTROPICAL. VWS IS NOT FORECAST TO
INCREASE SIGNIFICANTLY UNTIL AROUND TAU 48. ANIMATED WATER VAPOR
IMAGERY INDICATES TY 16W IS BEGINNING TO OPEN UP A POLEWARD OUTFLOW
CHANNEL INTO THE MID-LATITUDE WESTERLIES, WHICH WILL IMPROVE ALREADY
ROBUST RADIAL OUTFLOW. ADDITIONALLY, THE FORECAST TRACK IS ALIGNED
WITH
THE WARM WATERS OF THE KUROSHIO CURRENT, PROVIDING VERY FAVORABLE
SSTS LEADING UP TO ITS INITIAL LANDFALL OVER KYUSHU. INTENSITY
GUIDANCE IS IN GOOD AGREEMENT, CALLING FOR SLIGHT INTENSIFICATION
OVER THE NEXT 36 HOURS WHILE NOTED ENVIRONMENTAL CONDITIONS REMAIN
FAVORABLE. AFTER TAU 48, THE COMBINED EFFECTS OF LAND INTERACTION
WITH KYUSHU, FOLLOWED BY COOLER WATERS OF THE SEA OF JAPAN AND
SIGNIFICNATLY INCREASED VWS WILL SERVE TO BEGIN A RAPID WEAKENING OF
THE SYSTEM AT THE SAME TIME IT UNDERGOES EXTRATROPICAL TRANSITION
(ETT).
   C. BEYOND TAU 72, TY GONI WILL TRACK MORE NORTHWARD AS
SUBTROPICAL RIDGING TO THE EAST AMPLIFIES. THE SYSTEM WILL CONTINUE
TO WEAKEN AS IT TRACKS OVER THE COLD SEA OF JAPAN AND DEEPER INTO
THE BAROCLINIC ZONE. GONI WILL COMPLETE ETT BY THE TIME IT MAKES
LANDFALL INTO RUSSIA NEAR VLADIVOSTOK, AND POTENTIALLY EVEN SOONER.
DYNAMIC GUIDANCE IS IN TIGHT AGREEMENT UP TO TAU 48 THEN SPREADS
SIGNIFICANTLY AFTERWARDS, LENDING HIGH CONFIDENCE ONLY TO THE NEAR-
TO MID-TERM PORTION OF THE JTWC FORECAST.//
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