Tropical Storm FUNG-WONG Advisory 18 Σεπ.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 16W (FUNG-WONG)
WARNING NR 02//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 16W (FUNG-WONG), LOCATED APPROXIMATELY
490 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD
AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
(EIR) SATELLITE IMAGERY DEPICTS A CENTRAL DENSE OVERCAST FEATURE
WITH GOOD BANDING ON THE WESTERN AND SOUTHERN PERIPHERY WRAPPING
INTO A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC). A 171647Z
GCOM-W1 MICROWAVE IMAGE ALSO REVEALS INCREASED CENTRAL DEEP
CONVECTION ON THE SOUTHERN AND WESTERN SIDES OF THE SYSTEM. A
171307Z ASCAT PASS SHOWS WIND SPEEDS OF AT LEAST 25-30 KNOTS WITH
SOME SOUTHWEST TO NORTHEAST ELONGATION OF THE LLCC. THE CURRENT
POSITION IS BASED ON THE EIR AND AFOREMENTIONED MICROWAVE IMAGES
WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 30
KNOTS BASED ON DVORAK INTENSITY ESTIMATES OF 30 KNOTS FROM PGTW AND
RJTD. UPPER-LEVEL ANALYSIS INDICATES GOOD EQUATORWARD OUTFLOW AND A
LOW (5-15 KNOT) VERTICAL WIND SHEAR ENVIRONMENT, AN OVERALL
FAVORABLE UPPER LEVEL ENVIRONMENT. TD 16W IS CURRENTLY TRACKING
ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE
NORTH.
3. FORECAST REASONING.
   A. THERE ARE SIGNIFICANT CHANGES IN THE FORECAST TRACK IN THE
EARLY TAUS AND SIGNIFICANT CHANGES IN INTENSITIES IN THE EXTENDED
FORECAST.
   B. OVER THE NEXT 24 HOURS, TD 16W WILL TRACK TO THE NORTHWEST
UNDER THE INFLUENCE OF A STR TO THE NORTHEAST OF THE SYSTEM. AS THE
STR BEGINS TO BREAK DOWN, THE SYSTEM WILL CONTINUE TO THE NORTHWEST
AND SLOW DOWN UNDER A WEAKER STEERING ENVIRONMENT. MODELS ARE IN
GOOD AGREEMENT OF THE TRACK THROUGH TAU 36, WITH DIVERGENCE IN THE
FORECASTS BEYOND THAT TIME. THERE IS THE POSSIBILITY OF A RAPID
INTENSIFICATION SCENARIO AS THE SYSTEM TRACKS OVER WARM SSTS IN
ADDITION TO A FAVORABLE UPPER-LEVEL ENVIRONMENT. THE OFFICIAL
FORECAST IS IN CLOSE ALIGNMENT WITH THE MULTI-MODEL CONSENSUS
THROUGH TAU 48. BEYOND THAT, EXPECT TD FUNG-WONG, TO BEGIN A SLOW
TURN POLEWARD DUE TO A BREAK IN THE STR ASSOCIATED WITH A DEEP
SUBTROPICAL TROUGH. EXPECT INTENSITY TO MAINTAIN AT 85 KNOTS FROM
TAU 48 THOUGH TAU 72 DUE TO SOME INCREASED SHEAR AND THE POSSIBILITY
OF LAND INTERACTION WITH NORTHEASTERN LUZON.
   C. IN THE EXTENDED TAUS, INCREASING INTERACTION WITH THE MID-
LATITUDE WESTERLIES NORTH OF 25 DEGREES NORTH WILL SLOWLY WEAKEN THE
STRUCTURE OF TD 16W. AROUND TAU 96, TD 16W WILL ACCELERATE
NORTHEASTWARD AS IT BECOMES EMBEDDED IN THE BAROCLINIC BOUNDARY AND
WILL COMPLETE EXTRA-TROPICAL TRANSITION BY THE END OF THE FORECAST
PERIOD AS A STRONG COLD-CORE LOW. EXPECT THE SYSTEM TO TRACK TO THE
SOUTH OF SHIKOKU DUE TO THE PERSISTENT UPPER LEVEL JET THAT
MAINTAINS OVER THE KENSAI THROUGH KANTO REGIONS OF JAPAN THROUGHOUT
THE FORECAST PERIOD.  MODEL GUIDANCE IS DIVIDED IN THESE LATER TAUS
WITH THE JAPANESE ENSEMBLE TAKING A MUCH SHARPER RECURVE TO THE EAST
AND THE GFS ENSEMBLE AND ECMWF DEPICTING A SLOWER TURN AND HAVE THE
SYSTEM TRACKING WEST OF THE FIRST ISLAND CHAIN. JTWC'S FORECAST IS
MORE ALIGNED WITH THE GFS AND ECMWF SOLUTIONS DUE TO THE MORE LIKELY
SCENARIO OF THE STR TO THE EAST OF THE SYSTEM BUILDING IN MORE
SLOWLY AND NOT AS STRONG. DUE TO FAIR INITIAL POSITION CONFIDENCE
AND SOME SLIGHT DIFFERENCES IN THE EXTENT AND SPEED OF THE RECURVE
SCENARIO, THERE IS OVERALL LOW CONFIDENCE IN THE FORECAST TRACK
WHICH IS POSITIONED SLIGHTLY WEST OF MULTI-MODEL CONSENSUS.//
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