WTPN31 PGTW 120900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL DEPRESSION 16W (CHAN-HOM) WARNING NR 031// RMKS/ 1. TROPICAL DEPRESSION 16W (CHAN-HOM) WARNING NR 031 02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 120600Z --- NEAR 29.4N 142.4E MOVEMENT PAST SIX HOURS - 180 DEGREES AT 08 KTS POSITION ACCURATE TO WITHIN 020 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: 29.4N 142.4E --- FORECASTS: 12 HRS, VALID AT: 121800Z --- 28.7N 142.9E 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: 135 DEG/ 04 KTS --- 24 HRS, VALID AT: 130600Z --- 28.2N 143.5E MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 120900Z POSITION NEAR 29.2N 142.5E. 12OCT20. TROPICAL DEPRESSION (TD) 16W (CHAN-HOM), LOCATED APPROXIMATELY 138 NM NORTH OF CHICHI JIMA, HAS TRACKED SOUTHWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A FULLY-EXPOSED SYSTEM WITH LOW-LEVEL CLOUD LINES WRAPPING INTO A DEFINED CENTER, WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. A 120648Z SSMIS 91GHZ IMAGE REVEALS SHALLOW BANDING WRAPPING INTO A DEFINED LOW-LEVEL CIRCULATION CENTER WITH NO DEEP CONVECTION. THE INITIAL INTENSITY IS ASSESSED AT 25 KNOTS BASED ON RECENT ASCAT DATA. ENVIRONMENTAL ANALYSIS INDICATES UNFAVORABLE CONDITIONS WITH MODERATE (20-25 KNOTS) VERTICAL WIND SHEAR, CONVERGENCE ALOFT AND SIGNIFICANT DRY AIR ENTRAINMENT. TD 16W IS FORECAST TO TRACK SOUTHEASTWARD ALONG THE NORTHEAST PERIPHERY OF THE LOW-LEVEL SUBTROPICAL RIDGE AND IS FORECAST TO DISSIPATE 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 120600Z IS 10 FEET. REFER TO TROPICAL STORM 18W (NANGKA) WARNINGS (WTPN33 PGTW) FOR SIX-HOURLY UPDATES.// NNNN