WTPS31 PGTW 090900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18P (DONNA) WARNING NR 023// RMKS/ 1. TROPICAL CYCLONE 18P (DONNA) WARNING NR 023 02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 090600Z --- NEAR 20.1S 167.3E MOVEMENT PAST SIX HOURS - 130 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT REPEAT POSIT: 20.1S 167.3E --- FORECASTS: 12 HRS, VALID AT: 091800Z --- 21.6S 168.0E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 155 DEG/ 09 KTS --- 24 HRS, VALID AT: 100600Z --- 23.2S 168.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 155 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 150 DEG/ 13 KTS --- 36 HRS, VALID AT: 101800Z --- 25.4S 170.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 145 DEG/ 19 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 110600Z --- 28.4S 172.7E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 115 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT --- REMARKS: 090900Z POSITION NEAR 20.5S 167.5E. TROPICAL CYCLONE 18P (DONNA), LOCATED APPROXIMATELY 138 NM NORTH- NORTHEAST OF NOUMEA, NEW CALEDONIA, HAS TRACKED SOUTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A RAPIDLY WEAKENING SYSTEM WITH WARMING CLOUD TOPS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE EXTRAPOLATED FROM A RAGGED EYE FEATURE OBSERVED IN A 090432Z 91 GHZ SSMIS IMAGE. THE INITIAL INTENSITY ASSESSMENT OF 90 KNOTS IS BASED ON THE LOWER ENVELOP OF MULTI-AGENCY CURRENT INTENSITY DVORAK ESTIMATES RANGING FROM T5.0 TO T5.5 (90 TO 102 KNOTS). ENVIRONMENTAL CONDITIONS CONTINUE TO DETERIORATE AND WILL WEAKEN THE SYSTEM SIGNIFICANTLY OVER THE NEXT 48 HOURS. AN APPROACHING TROUGH FROM THE WEST IS INTRODUCING STRONG WESTERLY FLOW ALOFT, THUS IMPEDING THE POLEWARD EXHAUST CHANNEL AND WILL STEADILY INCREASE VERTICAL WIND SHEAR THROUGHOUT THE FORECAST PERIOD. TC DONNA IS ALSO DRIFTING INTO COOLER WATERS AND THIS TREND WILL CONTINUE ALONG THE FORECAST TRACK. TC DONNA WILL CONTINUE TRACKING SOUTHEASTWARD INTO THE BAROCLINIC REGION OF THE APPROACHING TROUGH AND BEGIN TRANSITIONING INTO AN EXTRATROPICAL SYSTEM IN THE NEXT 24 TO 36 HOURS. TC DONNA WILL BECOME EXTRATROPICAL BY TAU 48. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 090600Z IS 28 FEET. NEXT WARNINGS AT 092100Z AND 100900Z. REFER TO TROPICAL CYCLONE 19P (ELLA) WARNINGS (WTPS32 PGTW) FOR SIX-HOURLY UPDATES.//