WDPN32 PGTW 100300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 27W (TWENTYSEVEN) 
WARNING NR 02//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 27W (TWENTYSEVEN), LOCATED APPROXIMATELY 
210 NM SOUTH OF TAIPEI, TAIWAN, HAS TRACKED WEST-SOUTHWESTWARD AT 08
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY DEPICTS AN EXPOSED, DEFINED LOW-LEVEL CIRCULATION CENTER 
(LLCC) WITH IMPROVED DEEP CONVECTIVE BANDING OVER THE SOUTHERN 
SEMICIRCLE. A 092158Z WINDSAT 37GHZ IMAGE AND ANIMATED RADAR IMAGERY 
FROM THE TAIWAN RADAR REVEAL AN ORGANIZED LLCC WITH NARROW BANDING 
WRAPPING INTO A DEFINED CENTER, WHICH SUPPORTS THE CURRENT POSITION 
WITH GOOD CONFIDENCE. THE CURRENT INTENSITY IS ASSESSED AT 30 KNOTS 
BASED ON A PGTW DVORAK INTENSITY ESTIMATE OF T2.0 (30 KNOTS).
ADDITIONALLY, A 09/21Z SURFACE OBSERVATION FROM LAN YU (59567), 
APPROXIMATELY 60NM WEST-NORTHWEST OF THE 09/21Z POSITION, INDICATES 
10-MINUTE MEAN SURFACE WINDS AT 040/33 KNOTS AND SLP NEAR 1005.3MB. 
UPPER-LEVEL ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT 
WITH MODERATE NORTHERLY VERTICAL WIND SHEAR (VWS) OFFSET BY 
DIFFLUENT EQUATORWARD OUTFLOW. FURTHERMORE, SST (29-30C) AND OCEAN 
HEAT CONTENT VALUES ARE CONDUCIVE FOR FURTHER DEVELOPMENT. TD 27W IS 
TRACKING WEST-SOUTHWESTWARD UNDER THE STEERING INFLUENCE OF A LOW- 
TO MID-LEVEL SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.     
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE 
PREVIOUS WARNING.
   B. TD 27W SHOULD CONTINUE TRACKING WESTWARD TO WEST-SOUTHWESTWARD 
THROUGH TAU 72 WITH A SLOW INTENSIFICATION TREND AND PEAK INTENSITY 
OF 40 KNOTS AT TAU 36 AS VWS RELAXES. NUMERICAL MODEL GUIDANCE IS IN 
FAIR AGREEMENT AND SUPPORTS THE TRACK OVER WATER TOWARD HONG KONG.
   C. AFTER TAU 72, THE SYSTEM IS FORECASTED TO GRADUALLY WEAKEN DUE 
TO INTERACTION WITH LAND AND IS EXPECTED TO DISSIPATE AS IT TRACKS 
OVER NORTHERN VIETNAM AFTER TAU 96. NUMERICAL MODEL GUIDANCE REMAINS 
IN FAIR AGREEMENT, THEREFORE, THERE IS LOW OVERALL CONFIDENCE IN THE 
JTWC FORECAST TRACK, WHICH IS POSITIONED CLOSE TO THE MULTI-MODEL 
CONSENSUS.//
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