WDPN32 PGTW 211500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (BEBINCA) WARNING 
NR 05//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 05W (BEBINCA), LOCATED APPROXIMATELY 228 NM 
SOUTH-SOUTHEASTWARD OF HONG KONG, HAS TRACKED NORTHWESTWARD AT 07 
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE 
IMAGERY DEPICTS AN EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH 
AN AREA OF PERSISTENT DEEP CONVECTION SHEARED OVER THE SOUTHWEST 
QUADRANT OF THE LLCC. A 211223Z SSMIS 37GHZ IMAGE SHOWS TIGHTLY-
CURVED, SHALLOW CONVECTIVE BANDING WRAPPING INTO A DEFINED CENTER 
WITH AN ISOLATED AREA OF DEEP CONVECTION DISPLACED OVER THE 
SOUTHWEST QUADRANT DUE TO STRONG (25 TO 30 KNOT) NORTHEASTERLY 
VERTICAL WIND SHEAR (VWS). THE INITIAL INTENSITY IS ASSESSED AT 35 
KNOTS BASED ON A DVORAK ESTIMATE OF 35 KNOTS FROM PGTW AND A SHIP 
OBSERVATION, LOCATED 37 NM WEST-SOUTHWEST OF THE CENTER, INDICATING 
WINDS 010 AT 32 KNOTS. ADDITIONALLY, THE INTENSITY IS ALSO SUPPORTED 
BY A 210400Z OSI-SAF OSCAT IMAGE AS WELL AS THE SSMIS WIND DATA. 
THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION BASED ON THE IR 
ANIMATION AND SSMIS IMAGE. TS 05W IS TRACKING QUICKLY ALONG THE 
SOUTHERN PERIPHERY OF A DEEP SUBTROPICAL RIDGE (STR) POSITIONED OVER 
SOUTHEAST CHINA.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TS 05W IS FORECAST TO CONTINUE TRACKING WEST-NORTHWESTWARD 
THROUGH TAU 36 THEN SHOULD TURN NORTHWESTWARD AS IT TRACKS ALONG THE 
SOUTHWEST PERIPHERY OF THE STR. DYNAMIC MODEL GUIDANCE IS IN TIGHT 
AGREEMENT THROUGH TAU 24 THEN DIVERGES SIGNIFICANTLY AS THE SYSTEM 
WEAKENS DUE TO LAND INTERACTION. THIS FORECAST REMAINS CONSISTENT 
WITH THE PREVIOUS FORECAST AND REMAINS POSITIONED CLOSE TO THE ECMWF 
SOLUTION, WHICH HAS REMAINED VERY CONSISTENT AND SHOWS A MORE 
REALISTIC TRACK INTO NORTHERN VIETNAM UNDER THE EAST-WEST ORIENTED 
STR. TS 05W IS EXPECTED TO WEAKEN AFTER TAU 12 DUE TO LAND 
INTERACTION AND CONTINUED STRONG VWS. THE SYSTEM SHOULD DISSIPATE 
OVER VIETNAM BY TAU 48. OVERALL, THERE IS HIGH CONFIDENCE IN THE 
JTWC FORECAST TRACK.//
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