WTXS31 PGTW 170900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE WARNING// RMKS/ 1. TROPICAL CYCLONE 06S (BERGUITTA) WARNING NR 019 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 170600Z --- NEAR 18.1S 60.2E MOVEMENT PAST SIX HOURS - 270 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 025 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 005 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT REPEAT POSIT: 18.1S 60.2E --- FORECASTS: 12 HRS, VALID AT: 171800Z --- 19.0S 59.0E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 230 NM SOUTHEAST QUADRANT 260 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 235 DEG/ 09 KTS --- 24 HRS, VALID AT: 180600Z --- 20.1S 57.4E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 240 NM SOUTHEAST QUADRANT 215 NM SOUTHWEST QUADRANT 125 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 235 DEG/ 11 KTS --- 36 HRS, VALID AT: 181800Z --- 21.4S 55.4E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 250 NM SOUTHEAST QUADRANT 220 NM SOUTHWEST QUADRANT 125 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 230 DEG/ 11 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 190600Z --- 22.8S 53.5E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 240 NM SOUTHEAST QUADRANT 215 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 210 DEG/ 11 KTS --- 72 HRS, VALID AT: 200600Z --- 26.7S 51.1E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 050 KT WINDS - 085 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 220 NM SOUTHEAST QUADRANT 175 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 175 DEG/ 11 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 210600Z --- 31.0S 51.4E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 200 NM NORTHEAST QUADRANT 240 NM SOUTHEAST QUADRANT 210 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 130 DEG/ 11 KTS --- 120 HRS, VALID AT: 220600Z --- 33.8S 55.4E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 320 NM SOUTHEAST QUADRANT 280 NM SOUTHWEST QUADRANT 235 NM NORTHWEST QUADRANT --- REMARKS: 170900Z POSITION NEAR 18.3S 59.9E. TROPICAL CYCLONE 06S (BERGUITTA), LOCATED APPROXIMATELY 204 NM NORTHEAST OF PORT LOUIS, MAURITIUS, HAS TRACKED WESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS FLARING CENTRAL CONVECTION WITH A DENSE OVERCAST LAYER OBSCURING THE LOW LEVEL CIRCULATION CENTER. THERE IS HIGH CONFIDENCE IN THE INITIAL POSITION WHICH IS BASED ON A 170528Z METOP- A ASCAT IMAGE SHOWING THE LLCC NEAR THE EDGE OF SWATH AND THE CORRESPONDING 89GHZ AMSU IMAGE DEPICTING WEAK CONVECTION EMANATING FROM THE CENTER SHEARED SLIGHTLY TO THE WEST. THE INITIAL INTENSITY IS ASSESSED AT 70 KNOTS WHICH IS BASED ON CURRENT INTENSITY DVORAK ESTIMATES RANGING FROM T4.0 TO T4.5 (65 TO 77 KNOTS). UPPER-LEVEL ANALYSIS SHOWS A POINT SOURCE DIRECTLY OVER THE SYSTEM WITH A STRONG POLEWARD FEED INTO THE MID-LATITUDE JET. SSTS IN THE AREA ARE ALSO WARM AROUND 28 CELSIUS. TC 06S IS CURRENTLY TRACKING WESTWARD ALONG THE NORTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE TO THE SOUTHEAST WITH A STRONG RIDGE EXTENSION PROTRUDING WESTWARD JUST SOUTH OF TC 06S. THE RIDGE EXTENSION IS FORECAST TO WEAKEN OVER THE NEXT 12 TO 24 HOURS AND GUIDE TC 06S ON A SOUTHWEST TRACK FOR THROUGH TAU 48. ENVIRONMENTAL CONDITIONS WILL REMAIN FAVORABLE TO SUSTAIN THE CURRENT INTENSITY AROUND 70 KNOTS WITH MINOR FLUCTUATIONS OVER THE NEXT 48 HOURS. AROUND TAU 72 A MID-LATITUDE TROUGH APPROACHING FROM THE WEST WILL ERODE THE WESTERN EXTENT OF THE RIDGE AXIS AND SHIFT THE TRACK TO SOUTH THEN SOUTHEAST AS IT ROUNDS THE RIDGE AXIS. INTERACTION WITH THE APPROACHING TROUGH WILL INDUCE VERTICAL WIND SHEAR AND BAROCLINIC INSTABILITY CONTRIBUTING TO A WEAKENING TREND. TC 06S IS FORECAST TO COMPLETE EXTRATROPICAL TRANSITION BY TAU 120 AS IT ACCELERATES SOUTHEASTWARD. DYNAMIC MODEL GUIDANCE SHOWS VERY GOOD AGREEMENT WITH A NARROW MARGIN OF UNCERTAINTY FOR THE FIRST 48 HOURS. ALTHOUGH MODEL SOLUTIONS HAVE BEEN SLOW TO ACCOUNT FOR THE PERSISTENT RIDGE TO THE SOUTH OF TC 06S, RESULTING IN A MORE WESTWARD TRACK IN THE LAST 24 HOURS THAN EXPECTED, SOLUTIONS HAVE CONSISTENTLY SHOWN GOOD AGREEMENT FOR A TRAJECTORY OVER THE ISLANDS OF MAURITIUS AND LA REUNION. OVERALL THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 170600Z IS 27 FEET. NEXT WARNINGS AT 171500Z, 172100Z, 180300Z AND 180900Z.//