WDPN31 PGTW 281500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (KONG-REY) WARNING
NR 11//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 14W (KONG-REY), LOCATED APPROXIMATELY 177 NM
SOUTH-SOUTHEASTWARD OF TAIPEI, TAIWAN, HAS TRACKED NORTHWARD AT
07 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE (EIR) IMAGERY DEPICTS A DEFINED LOW-LEVEL
CIRCULATION CENTER (LLCC) ASSOCIATED WITH PERSISTENT DEEP CONVECTION
OVERHEAD AS WELL AS RECENTLY DEVELOPED DEEP CONVECTION SHEARED TO
THE SOUTHWEST OF THE LLCC. A 281202Z 37 GHZ SSMIS MICROWAVE IMAGE
REVEALS SEVERAL TIGHTLY WRAPPED CONVECTIVE BANDS SPIRALING INTO THE
LLCC WITH THE BULK OF THE DEEP CONVECTION TO THE SOUTH AND SOUTHWEST
OF THE CIRCULATION CENTER. THE INITIAL POSITION IS BASED ON THE EIR
AND THE MICROWAVE IMAGE WITH FAIR CONFIDENCE. THE INITIAL INTENSITY
OF 50 KNOTS IS BASED ON CONGRUENT DVORAK INTENSITY ESTIMATES RANGING
FROM 45 TO 55 KNOTS. UPPER-LEVEL ANALYSIS INDICATES TS 14W IS JUST
SOUTH OF THE SUBTROPICAL RIDGE (STR) AXIS IN AN AREA OF MODERATE TO
HIGH (20-30 KNOTS) NORTHEASTERLY VERTICAL WIND SHEAR (VWS), WHICH IS
OFFSET BY STRONG WESTWARD AND EQUATORWARD OUTFLOW. TS 14W IS
CURRENTLY TRACKING ALONG THE SOUTHWEST PERIPHERY OF THE STR.
3. FORECAST REASONING.
A. NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 14W IS EXPECTED TO CONTINUE TRACKING NORTHWESTWARD UNDER
THE INFLUENCE OF THE STR THROUGH TAU 24. AFTER TAU 24, A MID-
LATITUDE TROUGH APPROACHING FROM THE NORTHWEST IS EXPECTED TO WEAKEN
THE STR AND CAUSE THE CYCLONE TO RECURVE NORTHEASTWARD. TS 14W IS
EXPECTED TO GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE FORECAST
PERIOD. THOUGH VWS IS FORECAST TO GRADUALLY DIMINISH AS THE SYSTEM
DRIFTS NORTH, LAND INTERACTION DUE TO THE CLOSE PROXIMITY TO TAIWAN
AND THE EAST COAST OF CHINA WILL DISRUPT THE LOW-LEVEL INFLOW AND
AID IN THE WEAKENING. ADDITIONALLY, THE APPROACHING MID-LATITUDE
TROUGH IS FORECAST TO FURTHER WEAKEN THE SYSTEM, AT APPROXIMATELY
TAU 36, AS IT ENCOUNTERS INCREASED VWS WITH THE ONSET OF STRONG
WESTERLIES. THE PASSAGE OF THE MID-LATITUDE TROUGH WILL BEGIN
EXTRATROPICAL TRANSITION AT TAU 48 AND COMPLETE TRANSITION BY TAU 72.
C. AFTER TAU 72, TS 14W IS EXPECTED TO ACCELERATE NORTHEASTWARD
ACROSS THE SOUTHEAST COAST OF JAPAN AS A COLD-CORE EXTRATROPICAL
SYSTEM. DYNAMIC MODEL GUIDANCE HAS FALLEN INTO GOOD AGREEMENT
THROUGHOUT THE FORECAST TRACK, THE ONLY EXCEPTION BEING GFDN, WITH
ONLY SLIGHT VARIATIONS IN TRACK SPEED AND INTENSITY AT THE LATER
TAUS. SOME UNCERTAINTY REMAINS AROUND THE RECURVE POINT AS THERE IS
THE POTENTIAL FOR THE SYSTEM TO TRACK FURTHER WESTWARD, TOWARDS THE
EAST COAST OF CHINA, AS THE STR MAY REMAIN FAIRLY STRONG OVER THE
NEXT 12 TO 36 HOURS. THIS COULD CAUSE TRACK SPEEDS TO SLOW BETWEEN
TAU 12 AND 36 AND THE STORM TO MOVE FURTHER WEST BEFORE RECURVING.
THE ECMWF TRACK FORECAST HAS FALLEN IN LINE WITH THE BULK OF THE
MUTLI-MODEL CONSENSUS WHILE THE GFS FORECAST CONTINUES TO EXHIBIT
THE MOST WESTWARD RECURVING TRACK. THE JTWC FORECAST IS LAID BETWEEN
THE MULTI-MODEL CONSENSUS AND ECMWF/GFS IN THE EARLY TAUS AND IS
SLIGHTLY FASTER THAN AND TO THE RIGHT OF CONSENSUS, DUE TO A KNOWN
HISTORICAL BIAS TO ACCOUNT FOR THE HIGH TERRAIN IN JAPAN, IN THE
EXTENDED TAUS. THERE IS LOW CONFIDENCE IN THE FORECAST TRACK DUE TO
THE UNCERTAINTY AROUND THE RECURVE POINT.//
NNNN
TXPQ23 KNES 281416
TCSWNP
A. 14W (KONG-REY)
B. 28/1332Z
C. 23.1N
D. 122.7E
E. THREE/MTSAT
F. T3.5/3.5/D0.5/24HRS
G. IR/EIR/SWIR/SSMIS
H. REMARKS...1202Z SSMIS DATA WAS HELPFUL IN FIXING THE CENTER AND THE
37GHZ DATA SHOWED A COMPLETELY EXPOSED CENTER WITH CONVECTION SHEARED
TO ITS SOUTH.
AT 1332Z CENTER IS MORE THAN 1/3 DEGREE INTO THE DEEP
CONVECTION AS SEEN IN MTSAT LWIR IMAGERY. THIS RESULTS IN A DT OF 3.5
USING THE SHEAR PATTERN. MET AND PT ARE ALSO 3.5. FT IS BASED ON DT.
I. ADDL POSITIONS
28/1202Z 22.9N 122.7E SSMIS
...TURK
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