WTPN32 PGTW 302100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL DEPRESSION 21W (ETAU) WARNING NR 016// RMKS/ 1. TROPICAL DEPRESSION 21W (ETAU) WARNING NR 016 02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 301800Z --- NEAR 31.7N 166.8E MOVEMENT PAST SIX HOURS - 050 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 060 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 BECOMING SUBTROPICAL REPEAT POSIT: 31.7N 166.8E --- FORECASTS: 12 HRS, VALID AT: 310600Z --- 33.7N 167.6E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL VECTOR TO 24 HR POSIT: 005 DEG/ 13 KTS --- 24 HRS, VALID AT: 311800Z --- 36.3N 168.0E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL --- REMARKS: 302100Z POSITION NEAR 32.2N 167.0E. 30AUG26. TROPICAL DEPRESSION 21W (ETAU), LOCATED APPROXIMATELY 744 NM NORTH OF WAKE ISLAND, HAS TRACKED NORTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED IMAGERY REVEALS TROPICAL DEPRESSION (TD) 21W IS A HIGHLY ELONGATED SYSTEM POSITIONED DIRECTLY UNDER AN UPPER-LEVEL LOW. WITHIN THE LAST FEW HOURS, 21W CROSSED THE 26C ISOTHERM AND BEGAN SUBTROPICAL TRANSITION. ENVIRONMENTAL ANALYSIS REVEALS A HIGHLY UNFAVORABLE ENVIRONMENT, CHARACTERIZED BY HIGH (30-35 KTS) VERTICAL WIND SHEAR, COOL (25-26 C) SEA SURFACE TEMPERATURES, POOR OUTFLOW ALOFT, AND PERSISTENT DRY AIR ENTRAINMENT. 21W IS FORECAST TO CONTINUE TRACKING POLEWARD WHILE IT QUICKLY COMPLETES SUBTROPICAL TRANSITION. ADDITIONALLY, DETERMINISTIC MODEL GUIDANCE DEPICTS 21W DISSIPATING COMPLETELY WITHIN 12 HOURS. INTENSITY AIDS ARE IN STRONG AGREEMENT THAT 21W WILL MAINTAIN ITS INTENSITY FOR THE DURATION OF THE FORECAST PERIOD. SUBTROPICAL TRANSITION IS FORECAST TO OCCUR WITHIN 12 HOURS. 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. MINIMUM CENTRAL PRESSURE AT 301800Z IS 991 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 301800Z IS 20 FEET. REFER TO TROPICAL STORM 20W (BANG-LANG) FINAL WARNING (WTPN33 PGTW).// NNNN