WTPN52 PGTW 260900 WARNING ATCP MIL 21W NWP 110926070715 2011092606 21W HAITANG 008 02 270 06 SATL 040 T000 168N 1105E 030 T012 169N 1085E 030 T024 172N 1064E 025 T036 176N 1042E 020 AMP 024HR DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND 036HR DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND SUBJ: TROPICAL DEPRESSION 21W (HAITANG) WARNING NR 008 1. TROPICAL DEPRESSION 21W (HAITANG) WARNING NR 008 DOWNGRADED FROM TROPICAL STORM 21W 02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 260600Z --- NEAR 16.8N 110.5E MOVEMENT PAST SIX HOURS - 270 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY REPEAT POSIT: 16.8N 110.5E --- FORECASTS: 12 HRS, VALID AT: 261800Z --- 16.9N 108.5E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 280 DEG/ 10 KTS --- 24 HRS, VALID AT: 270600Z --- 17.2N 106.4E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 36 HR POSIT: 280 DEG/ 11 KTS --- 36 HRS, VALID AT: 271800Z --- 17.6N 104.2E MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 260900Z POSITION NEAR 16.8N 110.0E. TROPICAL DEPRESSION (TD) 21W (HAITANG), LOCATED APPROXIMATELY 170 NM EAST OF HUE, VIETNAM, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH ISOLATED DEEP CONVECTION SHEARED WEST OF THE CENTER. A 260122Z SSMIS 37 GHZ IMAGE INDICATES A DEFINED LLCC WITH SHALLOW CONVECTIVE BANDS WRAPPING INTO THE SLIGHTLY ELONGATED CENTER. A 260130Z ASCAT IMAGE SHOWS 25-30 KNOT WINDS ASSOCIATED WITH THE SYSTEM. ANIMATED WATER VAPOR IMAGERY AND UW-CIMSS PRODUCTS CONTINUE TO INDICATE DIFFLUENT EASTERLY FLOW AND MODERATE (20 KNOTS) VERTICAL WIND SHEAR. THE SYSTEM WAS DOWNGRADED TO TD STRENGTH (30 KNOTS) BASED ON THE ASCAT DATA, ELONGATING LLCC AND DVORAK ESTIMATES RANGING FROM 25-30 KNOTS. TD 21W IS EXPECTED TO TRACK WESTWARD UNDER THE LOW-LEVEL SUBTROPICAL RIDGE AND DISSIPATE OVER LAND BY TAU 36. MODEL GUIDANCE IS TIGHTLY CLUSTERED. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 260600Z IS 12 FEET. NEXT WARNINGS AT 261500Z, 262100Z, 270300Z AND 270900Z. REFER TO TYPHOON 20W (NESAT) 2111092306 154N1094E 15 2111092312 154N1099E 15 2111092318 155N1104E 20 2111092400 155N1111E 20 2111092406 154N1117E 25 2111092412 154N1123E 30 2111092418 159N1130E 30 2111092500 166N1130E 30 2111092506 169N1125E 35 2111092512 169N1120E 35 2111092518 168N1116E 35 2111092600 168N1111E 35 2111092606 168N1105E 30 NNNN