WDPN32 PGTW 300300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (WUTIP) WARNING NR 14//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 20W (WUTIP), LOCATED APPROXIMATELY 73 NM NORTH OF DA
NANG, VIETNAM, HAS TRACKED WESTWARD AT 15 KNOTS OVER THE PAST
SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY INDICATES THAT TY 20W 
HAS WEAKENED SLIGHTLY OVER THE PAST SIX HOURS AS IT APPROACHES 
VIETNAM BUT HAS MAINTAINED AN EYE, WHICH LENDS GOOD CONFIDENCE IN 
THE INITIAL POSITION. A 292010Z AMSU 89H IMAGE DEPICTS A MICROWAVE 
EYE FEATURE WITH DEEP CONVECTIVE BANDING OVER THE SOUTHERN SEMI-
CIRCLE. ANIMATED WATER VAPOR IMAGERY INDICATES THAT THE SYSTEM IS 
UNDER WEAK EASTERLY VERTICAL WIND SHEAR, HOWEVER, POLEWARD OUTFLOW 
HAS DECREASED OVER THE PAST 18 HOURS AS THE UPPER-LEVEL SHORTWAVE 
TROUGH PROPAGATES NORTHEASTWARD INTO NORTHEAST CHINA. THE SLIGHTLY 
DEGRADED UPPER-LEVEL ENVIRONMENT IN ADDITION TO SOME INITIAL LAND 
INTERACTION HAS LED TO A GENERAL WEAKENING TREND. THE INITIAL 
INTENSITY IS ASSESSED AT 75 KNOTS BASED ON DVORAK CURRENT INTENSITY 
ESTIMATES RANGING FROM 77 TO 90 KNOTS. TY 20W IS TRACKING WESTWARD 
UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE POSITIONED TO 
THE NORTH. 
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TY 20W IS FORECAST TO CONTINUE TRACKING WESTWARD THROUGH THE 
FORECAST PERIOD AND WILL MAKE LANDFALL NEAR TAU 12. DYNAMIC MODEL 
GUIDANCE IS IN VERY TIGHT AGREEMENT THEREFORE THERE IS HIGH 
CONFIDENCE IN THE JTWC TRACK FORECAST, WHICH IS POSITIONED CLOSE TO 
THE MULTI-MODEL CONSENSUS. TY 20W IS FORECAST TO DISSIPATE OVER LAND 
BY TAU 36.//
NNNN