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![]() Tropical Cyclone 199901 [Australian Region][South Indian Ocean][South Pacific Ocean][Southern Hemisphere][Summaries and Track Data] |
WTXS31 PGTW 980723 09:00z 1. TROPICAL CYCLONE 01S WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 230600Z1 --- 10.5S6 76.4E7 MOVEMENT PAST SIX HOURS - 260 DEGREES AT 07 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 REPEAT POSIT: 10.5S6 76.4E7 --- FORECASTS: 12 HRS, VALID AT: 231800Z4 --- 10.7S8 75.0E2 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT VECTOR TO 24 HR POSIT: 260 DEG/ 07 KTS --- 24 HRS, VALID AT: 240600Z2 --- 11.0S2 73.6E6 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 060 NM SOUTH SEMICIRCLE 050 NM ELSEWHERE VECTOR TO 36 HR POSIT: 260 DEG/ 07 KTS --- 36 HRS, VALID AT: 241800Z5 --- 11.2S4 72.2E1 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 060 NM SOUTH SEMICIRCLE 050 NM ELSEWHERE VECTOR TO 48 HR POSIT: 260 DEG/ 06 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 250600Z3 --- 11.4S6 70.9E6 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 060 NM SOUTH SEMICIRCLE 050 NM ELSEWHERE VECTOR TO 72 HR POSIT: 255 DEG/ 07 KTS --- 72 HRS, VALID AT: 260600Z4 --- 12.1S4 68.0E4 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 060 NM SOUTH SEMICIRCLE 050 NM ELSEWHERE --- REMARKS: 230900Z4 POSITION 10.5S6 76.0E3. TROPICAL DEPRESSION 01S IS MOVING WEST AT 7 KNOTS. ANIMATED WATER VAPOR IMAGERY SHOWS THE MODERATE VERTICAL WIND SHEAR, WHICH HAS BEEN RETARDING THE SYSTEM=S INTENSIFICATION, HAS ABATED OVER THE PAST 12 HOURS. THE CURRENT WARNING POSITION IS BASED UPON VISIBLE SATELLITE IMAGERY AND THE INTENSITY IS BASED UPON SATELLITE INTERPRETATION OF A DVORAK CURRENT INTENSITY OF 2.0 (30 KNOTS). THE WIND RADII ARE A COMBINATION OF CLIMATOLOGY AND SATELLITE INTERPRETATION. THE FORECAST TRACK IS IN AGREEMENT WITH THE TROPICAL FORECAST AIDS AS THE SYSTEM TRAVELS NORTH OF THE SUBTROPICAL RIDGE. SINCE NOGAPS ANALYSIS SHOWS THE TROPICAL DEPRESSION MAY COME UNDER ADDITIONAL SHEAR WITHIN THE NEXT 36 HOURS, WHICH WOULD RETARD FURTHER INTENSIFICATION, THE SYSTEM IS FORECAST TO INTENSIFY JUST SLIGHTLY WITHIN THE NEXT 72 HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 230600Z1 IS 12 FEET. REFER TO WWIO30 PGFW FOR ADDITIONAL SEA HEIGHT INFORMATION. THIS WARNING SUPERSEDES AND CANCELS NAVPACMETOCCEN WEST GU 230451Z5 JUL 98 TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW 230500Z0) NEXT WARNINGS AT 231500Z1 (DTG 231351Z5), 232100Z8 (DTG 231951Z1), 240300Z9 (DTG 240151Z3) AND 240900Z5 (DTG 240751Z9).// ========================================================================= WTXS31 PGTW 980723 15:00z 1. TROPICAL CYCLONE 01S WARNING NR 002 01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 231200Z8 --- 9.9S8 75.8E0 MOVEMENT PAST SIX HOURS - 280 DEGREES AT 06 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 REPEAT POSIT: 9.9S8 75.8E0 --- FORECASTS: 12 HRS, VALID AT: 240000Z6 --- 9.8S7 74.4E5 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT VECTOR TO 24 HR POSIT: 275 DEG/ 07 KTS --- 24 HRS, VALID AT: 241200Z9 --- 9.7S6 72.9E8 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT VECTOR TO 36 HR POSIT: 275 DEG/ 07 KTS --- 36 HRS, VALID AT: 250000Z7 --- 9.6S5 71.4E2 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT VECTOR TO 48 HR POSIT: 270 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 251200Z0 --- 9.6S5 70.0E7 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT VECTOR TO 72 HR POSIT: 275 DEG/ 07 KTS --- 72 HRS, VALID AT: 261200Z1 --- 9.4S3 67.1E4 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT --- REMARKS: 231500Z1 POSITION 9.9S8 75.4E6. TROPICAL CYCLONE 01S IS MOVING WESTWARD AT 06 KNOTS. MOST RECENT VISIBLE SATELLITE IMAGERY AS WELL AS ANIMATED INFRARED SATELLITE IMAGERY INDICATE THAT UPPER-LEVEL WIND SHEAR HAS INCREASED, COMPLETELY EXPOSING THE LOWER LEVEL CIRCULATION. HOWEVER, THE LOWER-LEVEL APPEARS TO BE BETTER ORGANIZED THAN BEFORE AND MORE INDICATIVE OF STRONG SURFACE WINDS. THE SYSTEM IS THEREFORE FORECAST TO REACH MINIMAL TROPICAL STORM STRENGTH BEFORE LOSING LOW-LEVEL ORGANIZATION TO THE CONTINUED UPPER-LEVEL SHEAR. TC 01S IS EXPECTED TO REMAIN EQUATORWARD, WITH SHALLOW STEERING INFLUENCE, OF THE SUBTROPICAL RIDGE THROUGHOUT THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 231200Z IS 12 FEET. NEXT WARNINGS AT 232100Z8 (DTG 231951Z1), 240300Z9 (DTG 240151Z3), 240900Z5 (DTG 240751Z9) AND 241500Z2 (DTG 241351Z6). ========================================================================= WTXS31 PGTW 980723 21:00z 1. TROPICAL CYCLONE 01S WARNING NR 003 01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 231800Z4 --- 9.6S5 076.2E5 MOVEMENT PAST SIX HOURS - 335 DEGREES AT 02 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 REPEAT POSIT: 9.6S5 076.2E5 --- FORECASTS: 12 HRS, VALID AT: 240600Z2 --- 9.3S2 075.4E6 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT VECTOR TO 24 HR POSIT: 270 DEG/ 06 KTS --- 24 HRS, VALID AT: 241800Z5 --- 9.3S2 074.2E3 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 36 HR POSIT: 270 DEG/ 06 KTS --- 36 HRS, VALID AT: 250600Z3 --- 9.3S2 072.9E8 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 48 HR POSIT: 265 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 251800Z6 --- 9.4S3 71.4E2 MAX SUSTAINED WINDS - 025 KT, GUSTS 040 KT DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 232100Z8 POSITION 9.5S4 076.0E3. TROPICAL CYCLONE 01S IS QUASISTATIONARY. THE WARNING POSITION IS BASED PRIMARILY ON A 231558Z4 MICROWAVE IMAGER (SSM/I) PASS. OVER THE LAST SIX HOURS, DEEP AND MID-LEVEL CONVECTION HAS SHEARED OFF. THIS, ALONG WITH A LOSS OF CIRCULATION ORGANIZATION HAS MADE THE SYSTEM DIFFICULT TO POSITION. HOWEVER, OVER THE LAST TWO HOURS, SOME MID-LEVEL CONVECTION HAS REAPPEARED NEAR THE CENTER. TC 01S IS CURRENTLY IN AN AREA OF LIGHT STEERING. WITHIN THE NEXT 12 TO 18 HOURS, THE SYSTEM IS EXPECTED TO BECOME INFLUENCED BY THE SUBTROPICAL RIDGE LOCATED TO THE SOUTH-SOUTHEAST. UPPERLEVEL SHEAR IS FORECAST TO RE-INTENSIFY AND REMAIN A FAIRLY CONSTANT FACTOR THROUGH 48 HOURS. ALTHOUGH THE INTENSITY IS EXPECTED TO BE BELOW SOUTHERN HEMISPHERE WARNING CRITERIA THROUGH THE LAST 24 TO 36 HOURS, THE FORECAST IS EXTENDED DUE TO PROXIMITY TO DIEGO GARCIA. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 231800Z4 IS 12 FEET. NEXT WARNINGS AT 240300Z9 (DTG 240151Z3), 240900Z5 (DTG 240751Z9), 241500Z2 (DTG 241351Z6) AND 242100Z9 (DTG 241951Z2).// ========================================================================= WTXS31 PGTW 980724 03:00z 1. TROPICAL CYCLONE 01S WARNING NR 004 01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 240000Z6 --- 9.5S4 76.0E3 MOVEMENT PAST SIX HOURS - 295 DEGREES AT 02 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 REPEAT POSIT: 9.5S4 76.0E3 --- FORECASTS: 12 HRS, VALID AT: 241200Z9 --- 9.4S3 75.7E9 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT VECTOR TO 24 HR POSIT: 290 DEG/ 03 KTS --- 24 HRS, VALID AT: 250000Z7 --- 9.2S1 75.1E3 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 36 HR POSIT: 270 DEG/ 03 KTS --- 36 HRS, VALID AT: 251200Z0 --- 9.2S1 74.4E5 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 240300Z9 POSITION 9.5S4 75.9E1. TROPICAL CYCLONE 01S IS QUASISTATIONARY SOUTHEAST OF DIEGO GARCIA. THE WARNING POSITION IS BASED ON ANIMATED INFRARED IMAGERY. ANIMATED INFRARED AS WELL AS ANIMATED WATER VAPOR IMAGERY SHOW MODERATE VERTICAL WIND SHEAR IS ONCE AGAIN AFFECTING TOPICAL CYCLONE 01S. ALTHOUGH RECENT IMAGERY SHOWS SOME CONVECTION OVER THE LOW LEVEL CIRCULATION, NOGAPS ANALYSIS INDICATES THE SHEAR ENVIRONMENT WILL CONTINUE FOR THE REMAINDER OF THE FORECAST PERIOD AND THIS CONVECTION SHOULD BE SHEARED OFF TO THE SOUTHWEST. DUE TO THE HIGH SHEAR ENVIRONMENT, IT IS UNLIKELY THAT TC 01S WILL INTENSIFY AS IT MOVES SLOWLY WESTWARD. ALTHOUGH WE ARE CONTINUING THE WARNING DUE TO THE SYSTEM=S PROXIMITY TO DIEGO GARCIA, WE ARE SWITCHING TO 12 HOUR UPDATES. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 240000Z6 IS 12 FEET. NEXT WARNING IS AT 241500Z2 (DTG 241351Z6) AND 250300Z0 (DTG 250151Z4).// ========================================================================= WTXS31 PGTW 980724 15:00z 1. TROPICAL CYCLONE 01S WARNING NR 005 01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 241200Z9 --- 9.2S1 076.1E4 MOVEMENT PAST SIX HOURS - 360 DEGREES AT 01 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 REPEAT POSIT: 9.2S1 076.1E4 --- FORECASTS: 12 HRS, VALID AT: 250000Z7 --- 9.0S9 076.0E3 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT VECTOR TO 24 HR POSIT: 280 DEG/ 03 KTS --- 24 HRS, VALID AT: 251200Z0 --- 8.9S7 075.4E6 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 36 HR POSIT: 270 DEG/ 04 KTS --- 36 HRS, VALID AT: 260000Z8 --- 8.9S7 074.5E6 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 241500Z2 POSITION 9.2S1 076.1E4. TROPICAL CYCLONE 01S REMAINS QUASI-STATIONARY IN THE SOUTH INDIAN OCEAN. THE WARNING POSITION IS BASED ON VISIBLE SATELLITE IMAGARY. ANIMATED INFRARED AND WATER-VAPOR IMAGERY INDICATE THAT THE SYSTEM CONTINUES TO BE AFFECTED BY UPPER-LEVEL CROSS- EQUATORIAL SHEAR. CURRENTLY IN AN AREA OF MINIMAL STEERING, THE SYSTEM IS FORECAST TO BECOME INFLUENCED BY THE RIDGING LOCATED TO ITS WEST-SOUTHWEST AND BEGIN TO TRACK WESTWARD WITHIN THE NEXT 24 HOURS. TC 01S IS EXPECTED TO REMAIN WITHIN AN ENVIRONMENT OF SIGNIFICANT VERTICAL SHEAR THROUGHOUT THE FORECAST PERIOD, AND WEAKEN BELOW TROPICAL DEPRESSION STRENGTH AFTER THE 36 HOUR POSITION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 240000Z6 IS 12 FEET. NEXT WARNINGS AT 250300Z0 (DTG 250151Z4) AND 251500Z3 (DTG 251351Z7).// ========================================================================= WTXS31 PGTW 250300 1. TROPICAL CYCLONE 01S WARNING NR 006 01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 250000Z7 --- 8.8S6 77.2E6 MOVEMENT PAST SIX HOURS - 090 DEGREES AT 05 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 DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER REPEAT POSIT: 8.8S6 77.2E6 --- FORECASTS: 12 HRS, VALID AT: 251200Z0 --- 8.7S5 77.8E2 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 250300Z0 POSITION 8.8S6 77.4E8. ANIMATED INFRARED SATELLITE IMAGERY INDICATES TROPICAL CYCLONE 01S HAS ENTERED AN AREA WITH INCREASED VERTICAL WIND SHEAR. 242330Z4 INFRARED SATELLITE IMAGERY INDICATES MINIMAL CONVECTION REMAINS NEAR THE CENTER. THEREFOR, THIS SYSTEM HAS DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 250000Z7 IS 12 FEET. REFER TO WWIO30 PGFW FOR ADDITIONAL SEA HEIGHT INFORMATION. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WARNING CENTER (NAVPACMETOCCEN WEST GU). THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION.//
Document: 199901.htm
Updated: 26th December 2006 |
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