WTXS31 PGTW 201500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 21S (GUAMBE) WARNING NR 007// RMKS/ 1. TROPICAL CYCLONE 21S (GUAMBE) WARNING NR 007 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 201200Z --- NEAR 26.5S 36.5E MOVEMENT PAST SIX HOURS - 160 DEGREES AT 05 KTS POSITION ACCURATE TO WITHIN 025 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT REPEAT POSIT: 26.5S 36.5E --- FORECASTS: 12 HRS, VALID AT: 210000Z --- 27.8S 37.0E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 140 DEG/ 12 KTS --- 24 HRS, VALID AT: 211200Z --- 29.6S 38.7E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 125 DEG/ 20 KTS --- 36 HRS, VALID AT: 220000Z --- 31.9S 42.4E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 160 NM NORTHEAST QUADRANT 180 NM SOUTHEAST QUADRANT 230 NM SOUTHWEST QUADRANT 170 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 120 DEG/ 28 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 221200Z --- 34.4S 48.4E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 240 NM SOUTHEAST QUADRANT 270 NM SOUTHWEST QUADRANT 190 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 110 DEG/ 27 KTS --- 72 HRS, VALID AT: 231200Z --- 37.9S 61.2E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT --- REMARKS: 201500Z POSITION NEAR 26.8S 36.6E. 20FEB21. TROPICAL CYCLONE 21S (GUAMBE), LOCATED APPROXIMATELY 154 NM SOUTH-SOUTHEAST OF MAXIXE, MOZAMBIQUE, HAS TRACKED SOUTH- SOUTHEASTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED AN OVERALL SYMMETRICAL STRUCTURE AND A PINHOLE EYE EVEN AS THE CENTRAL CONVECTION CONTINUED TO WARM AND FEEDER BANDS UNRAVELED. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PINHOLE EYE, ADJUSTED SLIGHTLY FOR TILT, AND SPOT-ON WITH THE MICROWAVE EYE IN THE 1146Z AMSR2 PASS. THE INITIAL INTENSITY OF 65KTS IS BASED ON THE DVORAK ESTIMATES OF T4.0/65KTS FROM PGTW AND FMEE AND CONSISTENT WITH THE EYE FEATURES IN THE MSI AND MICROWAVE IMAGES. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH LOW (10-15KT) VERTICAL WIND SHEAR (VWS), GOOD POLEWARD OUTFLOW ALOFT, AND WARM (28-29C) SST. THE CYCLONE IS TRACKING ALONG THE WEST-NORTHWESTWARD PERIPHERY OF THE DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE EAST. TC 21S WILL MAINTAIN ITS INTENSITY AS IT ROUNDS THE WESTERN EDGE OF THE STR OVER THE NEXT 12 HRS. AFTERWARD, IT WILL TRACK AND ACCELERATE SOUTHEASTWARD ON THE POLEWARD SIDE OF THE STR. INITIAL EXPOSURE TO THE STRONG MID-LATITUDE WESTERLIES WILL SIGNIFICANTLY IMPROVE POLEWARD OUTFLOW, FUELING A SECONDARY INTENSIFICATION TO A PEAK OF 75KTS BY TAU 36. AFTERWARD, INCREASING VWS AND COOLING SST WILL GRADUALLY ERODE THE SYSTEM DOWN TO 45KTS BY TAU 72. CONCURRENTLY, BY TAU 48, TC GUAMBE WILL COMMENCE EXTRA-TROPICAL TRANSITION AS IT ENTERS THE BAROCLINIC ZONE, AND BECOME A STORM-FORCE COLD-CORE LOW BY TAU 72. NUMERICAL MODELS ARE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 201200Z IS 22 FEET. NEXT WARNINGS AT 210300Z AND 211500Z.// NNNN