WTPN31 PGTW 170900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL DEPRESSION 16W (SIXTEEN) WARNING NR 028//
RMKS/
1. TROPICAL DEPRESSION 16W (SIXTEEN) WARNING NR 028    
   01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   170600Z --- NEAR 13.4N 143.9E
     MOVEMENT PAST SIX HOURS - 275 DEGREES AT 12 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   REPEAT POSIT: 13.4N 143.9E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   171800Z --- 13.8N 141.3E
   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: 290 DEG/ 12 KTS
    ---
   24 HRS, VALID AT:
   180600Z --- 14.6N 139.0E
   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
170900Z POSITION NEAR 13.5N 143.3E.
17AUG21. TROPICAL DEPRESSION 16W (SIXTEEN), LOCATED APPROXIMATELY
61 NM WEST-SOUTHWEST OF ANDERSEN AFB, HAS TRACKED WESTWARD AT 12
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY (MSI) DEPICTS SPIRAL BANDS OF WEAK, UPPER LEVEL CONVECTION 
THAT WRAP INTO AN OBSCURED LOW LEVEL CIRCULATION CENTER. COMPOSITE 
RADAR IMAGERY AND A 170344Z 165 GHZ IMAGE DEPICT SHALLOW CONVECTION 
SURROUNDING THE LOW LEVEL CENTER WITH POCKETS OF DEEPER, ALBEIT 
DISORGANIZED, CONVECTION TO THE EAST AND NORTHEAST. THE COMBINATION 
OF SATELLITE, RADAR AND MICROWAVE IMAGERY LEND ONLY MEDIUM 
CONFIDENCE IN THE INITIAL POSITION DUE TO THE BROAD NATURE OF THE 
LOW LEVEL CIRCULATION. THE INITIAL INTENSITY OF 20 KTS IS PLACED 
WITH MEDIUM CONFIDENCE BASED ON THE OVERALL LACK OF ORGANIZED 
CONVECTIVE STRUCTURE. THE OVERALL ENVIRONMENT IS MARGINAL WITH VERY 
WARM SST VALUES (31-32 CELSIUS) OFFSET BY MODERATE TO HIGH VERTICAL 
WIND SHEAR (20-30 KTS). ADDITIONALLY, NORTHERLY UPPER LEVEL WINDS 
FROM RIDGING TO THE NORTH IS FURTHER HINDERING DEVELOPMENT. OVER THE 
NEXT 24 HOURS TD 16W WILL CONTINUE TO TRACK GENERALLY WESTWARD TO 
WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL 
RIDGE POSITIONED TO THE NORTH AND STRUGGLE TO CONSOLIDATE DUE TO THE 
CONTINUED MARGINAL ENVIRONMENT. NUMERICAL MODEL TRACK GUIDANCE IS IN 
TIGHT AGREEMENT, AND LENDS OVERALL HIGH CONFIDENCE IN THE FORECAST 
TRACK, HOWEVER THE INTENSITY FORECAST IS PLACED WITH LOW CONFIDENCE 
DUE TO A HIGH DEGREE OF SPREAD IN THE MODEL INTENSITY GUIDANCE. 
SPECIFICALLY, THE HWRF AND COAMPS MESOSCALE MODELS DEPICT SYSTEM 
INTENSIFICATION BEYOND 25 KTS BETWEEN TAUS 24 AND 48, HOWEVER GLOBAL 
MODELS DO NOT DEPICT THIS INTENSIFICATION SCENARIO. THIS REFLECTS 
THE CURRENT COMPLEX AND UNFAVORABLE THERMODYNAMIC ENVIRONMENT THAT, 
IN ADDITION TO THE DYNAMIC ENVIRONMENT, HAS THE POTENTIAL TO IMPROVE 
AS THE SYSTEM TRACKS FURTHER WESTWARD. 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 170600Z IS 15 FEET.
//
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