WTPN32 PGTW 211500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL DEPRESSION 20W (TWENTY) WARNING NR 005
RMKS/
1. TROPICAL DEPRESSION 20W (TWENTY) WARNING NR 005    
   02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   211200Z --- NEAR 24.1N 139.4E
     MOVEMENT PAST SIX HOURS - 195 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 035 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   REPEAT POSIT: 24.1N 139.4E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   220000Z --- 24.8N 138.7E
   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   VECTOR TO 24 HR POSIT: 355 DEG/ 11 KTS
    ---
   24 HRS, VALID AT:
   221200Z --- 27.0N 138.4E
   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
211500Z POSITION NEAR 24.3N 139.2E.
21OCT20. TROPICAL DEPRESSION 20W (TWENTY), LOCATED APPROXIMATELY 112 
NM WEST-SOUTHWEST OF IWO TO, JAPAN, HAS TRACKED SOUTH-SOUTHWESTWARD 
AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED 
(EIR) SATELLITE IMAGERY AND A 210854Z SSMIS 91 GHZ MICROWAVE IMAGE 
DEPICT A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH SOME 
WEAK BANDING WRAPPING IN FROM THE WEST. A BULLSEYE 211127Z ASCAT-A 
IMAGE REVEALING A SWATH OF 20-25KT WINDS TO THE NORTH AND NORTHWEST 
WITH WEAKER WINDS ELSEWHERE. BASED ON THE AFOREMENTIONED ASCAT 
IMAGE, THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION AND INITIAL 
INTENSITY OF 25 KTS. ENVIRONMENTAL ANALYSIS INDICATES AN UNFAVORABLE 
ENVIRONMENT WITH STRONG (40-45 KTS) VERTICAL WIND SHEAR (VWS) BEING 
SLIGHTLY OFFSET BY WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES AND 
EQUATORWARD OUTFLOW. TD 20W IS CURRENTLY TRACKING WITHIN A WEAK 
STEERING ENVIRONMENT AS A SHORTWAVE TROUGH POSITIONED TO THE 
NORTHEAST WEAKENED THE STEERING SUBTROPICAL RIDGE (STR). AS THE 
SHORTWAVE TROUGH PROPAGATES EASTWARD, THE STR WILL BEGIN TO REBUILD 
AND REORIENT POLEWARD ALLOWING TD 20W TO TURN NORTHWESTWARD THEN 
NORTHWARD, TRACKING ALONG THE PERIPHERY OF THE STR. PERSISTENT 
STRONG (40-45 KTS) VWS WILL CAUSE TD 20W TO QUICKLY WEAKEN, 
DISSIPATING BY TAU 12. THE REMNANTS OF THE SYSTEM WILL BE ABSORBED 
BY A DEVELOPING FRONT SOUTHEAST OF THE KANTO PLAIN. NUMERICAL MODEL 
GUIDANCE IS IN GOOD AGREEMENT. HOWEVER, DUE TO THE CURRENT WEAK 
STEERING ENVIRONMENT, THERE IS OVERALL FAIR CONFIDENCE IN THE JTWC 
FORECAST TRACK WHICH IS PLACED NEAR THE MULTI-MODEL CONSENSUS. THIS 
IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN 
PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF 
REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 211200Z IS 9 FEET. 
REFER TO TROPICAL STORM 19W (SAUDEL) WARNINGS (WTPN31 PGTW) FOR SIX-
HOURLY UPDATES.//
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