WTPN31 PGTW 122100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL DEPRESSION 18W (CONSON) WARNING NR 028// RMKS/ 1. TROPICAL DEPRESSION 18W (CONSON) WARNING NR 028 02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 121800Z --- NEAR 15.4N 109.1E MOVEMENT PAST SIX HOURS - 315 DEGREES AT 01 KTS POSITION ACCURATE TO WITHIN 045 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE AND RADAR 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: 15.4N 109.1E --- FORECASTS: 12 HRS, VALID AT: 130600Z --- 16.1N 108.0E MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 24 HR POSIT: 290 DEG/ 08 KTS --- 24 HRS, VALID AT: 131800Z --- 16.6N 106.5E MAX SUSTAINED WINDS - 015 KT, GUSTS 025 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 122100Z POSITION NEAR 15.6N 108.8E. 12SEP21. TROPICAL DEPRESSION (TD) 18W (CONSON), LOCATED APPROXIMATELY 59 NM SOUTHEAST OF DA NANG, VIETNAM, HAS TRACKED NORTHWESTWARD AT 01 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND ANIMATED RADAR IMAGERY DEPICT A DECAYING LOW- LEVEL CIRCULATION WITH A WEAKLY DEFINED CENTER. UPPER-LEVEL ANALYSIS INDICATES UNFAVORABLE CONDITIONS WITH MODERATE TO STRONG EASTERLY VERTICAL WIND SHEAR, WHICH WILL PERSIST THROUGH THE FORECAST PERIOD. SURFACE OBSERVATIONS FROM QUANG NGAI, 20NM TO THE SOUTHWEST, INDICATE STEADILY RISING SLP WITH A 12/18Z SLP VALUE AT 1001.4MB REFLECTING THE STEADY WEAKENING TREND. THE SYSTEM IS FORECAST TO TRACK NORTHWESTWARD INTO VIETNAM WITH DISSIPATION BY TAU 12. 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 121800Z IS 12 FEET. REFER TO TYPHOON 19W (CHANTHU) WARNINGS (WTPN32 PGTW) FOR SIX-HOURLY UPDATES.// NNNN