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AXAU01 APRF 171903 IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 1903 UTC 17/03/2024 Name: Tropical Low Identifier: 08U Data At: 1800 UTC Latitude: 17.5S Longitude: 112.7E Location Accuracy: within 30nm (55 km) Movement Towards: southeast (136 deg) Speed of Movement: 3 knots (5 km/h) Maximum 10-Minute Wind: 25 knots (45 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 998 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T2.0/2.0/S0.0/24HRS STT:S0.0/06HRS Pressure of outermost isobar: 1002 hPa Radius of outermost closed isobar: 160 nm (295 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 18/0000: 17.6S 112.6E: 045 (080): 030 (055): 996 +12: 18/0600: 17.9S 112.6E: 055 (100): 030 (055): 996 +18: 18/1200: 18.0S 112.5E: 065 (115): 030 (055): 996 +24: 18/1800: 18.0S 112.4E: 065 (125): 030 (055): 996 +36: 19/0600: 17.8S 112.0E: 070 (130): 030 (055): 996 +48: 19/1800: 17.6S 111.3E: 080 (150): 030 (055): 996 +60: 20/0600: 17.4S 110.2E: 095 (180): 030 (055): 997 +72: 20/1800: 17.2S 108.7E: 115 (210): 040 (075): 992 +96: 21/1800: 17.2S 105.3E: 150 (280): 045 (085): 989 +120: 22/1800: 18.0S 100.5E: 175 (330): 050 (095): 986 REMARKS: Tropical Low 08U is unlikely to develop significantly until Wednesday, while moving slowly west away from the Australian coast. Position is fair based on a 1419 UTC ASCAT-B pass which partially capture the centre. Convection continues to fluctuate, with colder cloud and lightning focussed west of the LLCC. Dvorak analysis: DT is based on weakly curved cold cloud with 0.3-0.4 wrap. The 24h trend is steady with MET and FT 2.0 and CI 2.0. Recent objective guidance: ADT 39kn, AiDT 37kn, DPRINT 33kn (all 1-min average) (SATCON N/A). Intensity is set at 25 kn based on recent scatterometry and Dvorak assessments. The environment is not favourable for development in the short term due to surrounding dry air and 20-25kn vertical wind shear. The forecast shear decreases from Monday and slow intensification is forecast during the mid-week period, reaching tropical cyclone intensity on Tuesday or Wednesday. Some NWP guidance indicates further intensification to category 2 later in the week as the system moves west across the southern Indian Ocean into a slightly more supportive upper environment. 08U is going through a period of slow motion due to the passage of a mid-level trough to the south causing a break in the mid-level ridge. From Tuesday the sub-tropical ridge is forecast to strengthen, maintaining a steady westerly track at faster speed during the mid-week period. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 18/0130 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 2 am March 18 tropical low 17.5S 112.7E 55 +6hr 8 am March 18 tropical low 17.6S 112.6E 80 +12hr 2 pm March 18 tropical low 17.9S 112.6E 100 +18hr 8 pm March 18 tropical low 18.0S 112.5E 115 +24hr 2 am March 19 tropical low 18.0S 112.4E 125 +36hr 2 pm March 19 tropical low 17.8S 112.0E 130 +48hr 2 am March 20 tropical low 17.6S 111.3E 150 +60hr 2 pm March 20 tropical low 17.4S 110.2E 180 +72hr 2 am March 21 1 17.2S 108.7E 210 -
WTXS32 PGTW 172100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 027// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 027 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 171800Z --- NEAR 17.4S 112.7E MOVEMENT PAST SIX HOURS - 240 DEGREES AT 02 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT REPEAT POSIT: 17.4S 112.7E --- FORECASTS: 12 HRS, VALID AT: 180600Z --- 17.6S 112.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 250 DEG/ 02 KTS --- 24 HRS, VALID AT: 181800Z --- 17.7S 112.2E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 290 DEG/ 02 KTS --- 36 HRS, VALID AT: 190600Z --- 17.6S 111.9E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 295 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 191800Z --- 17.2S 111.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 280 DEG/ 05 KTS --- 72 HRS, VALID AT: 201800Z --- 16.9S 108.9E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 275 DEG/ 08 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 211800Z --- 16.6S 105.4E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 265 DEG/ 11 KTS --- 120 HRS, VALID AT: 221800Z --- 16.8S 100.8E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT --- REMARKS: 172100Z POSITION NEAR 17.5S 112.7E. 17MAR24. TROPICAL CYCLONE 18S (EIGHTEEN), LOCATED APPROXIMATELY 304 NM NORTH-NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED WEST- SOUTHWESTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 171800Z IS 997 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 171800Z IS 24 FEET. NEXT WARNINGS AT 180300Z, 180900Z, 181500Z AND 182100Z. // NNNN
WDXS32 PGTW 172100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 027// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 17.4S 112.7E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 304 NM NORTH-NORTHWEST OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 02 KTS SIGNIFICANT WAVE HEIGHT: 24 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL CYCLONE (TC) 18S WITH FLARING CONVECTION PARTIALLY OBSCURING THE BROAD LOW-LEVEL CIRCULATION CENTER (LLCC) RIGHT AS THE SYSTEM REACHES DIURNAL MAXIMUM. MODERATE EASTERLY VERTICAL WIND SHEAR (VWS) OF 20-25KTS HAS DECOUPLED THE VORTEX AND HAS PREVENTED THE CYCLONE FROM INTENSIFYING AND HAS CAUSED A WESTWARD VERTICAL TILT WITH HEIGHT. THE SYSTEM REMAINS QUASI-STATIONARY (QS) AS THE A SUBTROPICAL RIDGE BUILDS TO THE SOUTHEAST, CAUSING TC 18S TO DRIFT IN A WESTWARD DIRECTION OVER THE LAST SIX HOURS. THE SYSTEM REMAINS IN RELATIVELY COOL BUT FAVORABLE SEA SURFACE TEMPERATURES (SST) RESULTING FROM OCEANIC UPWELLING OVER THE LAST FEW DAYS. THE INITIAL POSITION WAS ASSESSED WITH MEDIUM CONFIDENCE BASED ON ANIMATED EIR DEPICTING A PARTIALLY EXPOSED LLCC THAT BECOMES OBSCURED AS CONVECTION FLARES BUT IS UNLIKELY TO BE REPRESENTATIVE OF AN IMPROVED ENVIRONMENT DUE TO DIURNAL HEATING. THE INITIAL INTENSITY WAS ASSESSED WITH LOW CONFIDENCE BASED ON AGENCY AND OBJECTIVE FIXES BELOW. HOWEVER, A 171416Z METOP-B ASCAT UHR WIND SPEED PRODUCT DEPICTS AN ELONGATED CIRCULATION WITH A MAXIMUM OF 25KT WINDS 50NM TO THE NORTHEAST OF THE SYSTEM. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS KNES: T2.0 - 30 KTS DEMS: T2.5 - 35 KTS APRF: T2.0 - 30 KTS CIMSS SATCON: 39 KTS AT 1900Z CIMSS ADT: 41 KTS AT 171900Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY UNFAVORABLE VWS: 5-10 KTS SST: 28-29 CELSIUS OUTFLOW: WEAK RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 18S IS FORECAST TO CONTINUE DRIFTING IN A WEST-SOUTHWESTWARD DIRECTION FOR THE NEXT 24 HOURS BEFORE COMING UNDER THE INFLUENCE OF A STR TO THE SOUTHEAST WHICH WILL DRIVE THE SYSTEM WEST THROUGH THE END OF THE FORECAST PERIOD. THE WEAK NATURE OF THE STEERING ENVIRONMENT MAY RESULT IN THE SYSTEM TRANSITING FARTHER WEST OR SOUTH THAN REPRESENTED ON THE FORECAST IN THE NEAR-TERM. THE INTENSITY IS FORECAST TO REMAIN STAGNANT OVER THE NEXT 48 HOURS AS OCEAN HEAT CONTENT (OHC) REMAINS LOW AND THE UPPER-LEVEL FLOW IS NEARLY CONVERGENT. AS THE SYSTEM MOVES FARTHER OUT OF THE AREA, THERE IS A LIKELIHOOD THAT CONDITIONS WILL IMPROVE FOR INTENSIFICATION TO 50KTS BY TAU 120 AS TC 18S TRACKS OVER REGIONS OF HIGHER OHC AND VWS MAY DECREASE. MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT THAT TC 18S WILL REMAIN QS FOR THE NEXT 18-24 HOURS BEFORE TRACKING WEST ALONG THE NORTHERN SIDE OF A STR TO THE SOUTHEAST. HOWEVER, THE JTWC INTENSITY CONSENSUS IS NOT IN GOOD AGREEMENT WITH A MAXIMUM DIFFERENCE OF 85KTS. HAFS-A AND HWRF NOW PREDICT A PEAK OF 110KTS BETWEEN TAU 60-108, HOWEVER COAMPS-TC PREDICTS A BRIEF INCREASE TO 50KTS BY TAU 24 BEFORE CONSISTENTLY DECREASING TO 25KTS BY THE END OF THE FORECAST PERIOD. IT IS WORTH NOTING THAT HWRF, HAFS-A, SHIPS, AND GFS HAS BEEN FLAKY IN CONSISTENTLY FORECASTING SIGNIFICANT INTENSIFICATION THAT HAS NOT OCCURRED AND THEN FLIP-FLOPPING, WITH DRASTIC CHANGES OVER SHORT PERIODS OF TIME. GIVEN THE EXTREME RUN-TO-RUN INCONGRUENCE IN THE MODEL DATA, THE INTENSITY FORECAST IS MADE WITH LOW CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
最后于 2024-03-18 06:00:00 被ygsj24编辑 ，原因： -
AXAU01 APRF 180119 IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 0119 UTC 18/03/2024 Name: Tropical Low Identifier: 08U Data At: 0000 UTC Latitude: 17.8S Longitude: 112.8E Location Accuracy: within 30nm (55 km) Movement Towards: south southeast (150 deg) Speed of Movement: 3 knots (5 km/h) Maximum 10-Minute Wind: 30 knots (55 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 998 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T2.0/2.0/D0.5/24HRS STT:S0.0/06HRS Pressure of outermost isobar: 1004 hPa Radius of outermost closed isobar: 210 nm (390 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 18/0600: 18.0S 112.7E: 045 (080): 030 (055): 998 +12: 18/1200: 18.1S 112.7E: 055 (105): 030 (055): 998 +18: 18/1800: 18.1S 112.6E: 065 (115): 030 (055): 998 +24: 19/0000: 18.1S 112.4E: 070 (125): 030 (055): 998 +36: 19/1200: 17.8S 111.8E: 070 (135): 030 (055): 998 +48: 20/0000: 17.6S 110.9E: 085 (160): 030 (055): 998 +60: 20/1200: 17.5S 109.8E: 100 (190): 035 (065): 998 +72: 21/0000: 17.4S 108.3E: 115 (210): 040 (075): 994 +96: 22/0000: 17.4S 104.4E: 145 (265): 045 (085): 992 +120: 23/0000: 18.4S 98.8E: 180 (330): 050 (095): 988 REMARKS: Tropical Low 08U is unlikely to develop significantly until Wednesday, while moving slowly west away from the Australian coast. Position is fair based on animated vis satellite imagery. Convection continues to fluctuate, with two discrete areas of deeper convection being currently observed to the east and northwest of the LLCC. Dvorak analysis: DT is based on weakly curved cold cloud with 0.3 wrap. MET is 2.5 based on a standard development 24hr trend. PAT is 2.0 with FT/CI 2.0 based on PAT. Recent objective guidance: ADT 45kn, AiDT 36kn, DPRINT 37kn (all 1-min average). Intensity is set at 30 kn. The environment is not favourable for development in the short term due to surrounding dry air and ~20kn vertical wind shear. The shear is expected to decrease during today and slow intensification is forecast during the mid-week period, reaching tropical cyclone intensity on Wednesday. NWP guidance varies considerably in when intensity begins to increase with some strengthening into a tropical cyclone later today. Further intensification to category 2 later in the week is forecast but there is potential for a severe system as it moves into a more supportive upper environment later in the week. The upper bounds reflect the possibility of 08U intensifying during today despite currently being in an unfavourable environment. This could lead to it becoming a category 2 tropical cyclone on Tuesday and category 3 late Wednesday. Even under the worst-case scenario, 08U is highly likely to be too far west for any direct impacts to be experienced over any forecast sites. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 18/0730 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 8 am March 18 tropical low 17.8S 112.8E 55 +6hr 2 pm March 18 tropical low 18.0S 112.7E 80 +12hr 8 pm March 18 tropical low 18.1S 112.7E 105 +18hr 2 am March 19 tropical low 18.1S 112.6E 115 +24hr 8 am March 19 tropical low 18.1S 112.4E 125 +36hr 8 pm March 19 tropical low 17.8S 111.8E 135 +48hr 8 am March 20 tropical low 17.6S 110.9E 160 +60hr 8 pm March 20 tropical low 17.5S 109.8E 190 +72hr 8 am March 21 1 17.4S 108.3E 210 -
WTXS32 PGTW 180300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 028// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 028 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 180000Z --- NEAR 17.4S 112.3E MOVEMENT PAST SIX HOURS - 270 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT REPEAT POSIT: 17.4S 112.3E --- FORECASTS: 12 HRS, VALID AT: 181200Z --- 17.5S 112.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 285 DEG/ 02 KTS --- 24 HRS, VALID AT: 190000Z --- 17.4S 111.6E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 300 DEG/ 02 KTS --- 36 HRS, VALID AT: 191200Z --- 17.2S 111.2E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 285 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 200000Z --- 17.0S 110.3E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 275 DEG/ 06 KTS --- 72 HRS, VALID AT: 210000Z --- 16.8S 107.7E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 275 DEG/ 09 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 220000Z --- 16.6S 103.9E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 260 DEG/ 12 KTS --- 120 HRS, VALID AT: 230000Z --- 17.3S 98.8E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT --- REMARKS: 180300Z POSITION NEAR 17.4S 112.2E. 18MAR24. TROPICAL CYCLONE 18S (EIGHTEEN), LOCATED APPROXIMATELY 311 NM NORTH-NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED WESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 180000Z IS 998 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 180000Z IS 18 FEET. NEXT WARNINGS AT 180900Z, 181500Z, 182100Z AND 190300Z. // NNNN
WDXS32 PGTW 180300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 028// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 17.4S 112.3E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 311 NM NORTH-NORTHWEST OF LEARMONTH, AUSTRALIA MOVEMENT PAST 6 HOURS: WESTWARD AT 04 KTS SIGNIFICANT WAVE HEIGHT: 18 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS COLLAPSING DIURNAL CONVECTION PARTIALLY OBSCURING A LOW-LEVEL CIRCULATION CENTER (LLCC) AND WARMING CLOUD TOPS THROUGH WHICH GLIMPSES OF THE LLCC ARE REVEALED. THE SYSTEM IS CURRENTLY BEING WEAKLY STEERED WESTWARD ON THE NORTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) BUILDING TO THE SOUTHEAST. SEA SURFACE TEMPERATURES ARE FAVORABLE; HOWEVER, OCEAN HEAT CONTENT HAS DRAINED OVER THE PAST FEW DAYS AND WEAKLY SUPPORTS THE SYSTEM. MODERATE VERTICAL WIND SHEAR (VWS) OF 20-25KTS SHEARS THE VORTEX, PREVENTING VERTICAL ALIGNMENT OF THE VORTEX. WINDS ALOFT ARE CONVERGENT ABOVE THE CYCLONE, COMPLETELY ELIMINATING OUTFLOW SUPPORTING INTENSIFICATION. THE INITIAL POSITION WAS ASSESSED WITH MEDIUM CONFIDENCE BASED ON ANIMATED MSI SHOWING A PARTIALLY EXPOSED LLCC. THE INITIAL INTENSITY WAS ASSESSED BASED ON PERSISTENCE AND THE AGENCY AND OBJECTIVE FIXES LISTED BELOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: THE NORTHERN PERIPHERY OF A STR TO THE EAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS KNES: T2.5 - 35 KTS DEMS: T2.5 - 35 KTS APRF: T2.0 - 30 KTS CIMSS ADT: 45 KTS AT 172330Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY UNFAVORABLE VWS: 20-25 KTS SST: 28-29 CELSIUS OUTFLOW: WEAK RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 18S IS FORECAST TO CONTINUE TO WEAKLY DRIFT TO THE WEST-SOUTHWEST OVER THE NEXT 12 HOURS AS THE STR TO THE SOUTHEAST BUILDS, CURVING THE CYCLONE TO A WEST-NORTHWEST TRACK THROUGH TAU 36. BY TAU 48, THE SYSTEM IS EXPECTED TO BE DRIVEN DUE WEST THROUGH TAU 96, PICKING UP TRACK SPEED TO NINE KTS BY TAU 96. BETWEEN TAU 96 AND 120, TC 18S IS EXPECTED TO SLIGHTLY CURVE TO THE WEST-SOUTHWEST ONCE MORE WHILE ACCELERATING TO A SPEED OF 12KTS. THE INTENSITY IS FORECAST TO REMAIN UNCHANGED THROUGH THE FIRST 48 HOURS. SPECIFICALLY IN THE UPPER LEVELS, CONVERGENCE ALOFT WILL CAP THE VORTEX AND PREVENT AN EXHAUST MECHANISM THAT COULD LEAD TO INTENSIFICATION, DESPITE RELATIVELY LOW VWS AND FAVORABLE SEA SURFACE TEMPERATURES. THE UPPER-LEVEL FLOW IS EXPECTED TO IMPROVE BY TAU 60, ALLOWING FOR SLOW INTENSIFICATION TO 50KTS BY THE END OF THE FORECAST PERIOD. MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT THAT TC 18S WILL CRAWL, WALK, AND THEN RUN IN A WESTWARD DIRECTION. THE MAXIMUM CROSS-TRACK ERROR IS 150NM BY TAU 120, WITH ECM2 TO THE NORTH AND GFS TO THE SOUTH. THE INTENSITY GUIDANCE HAS DRASTICALLY INCREASED ONCE AGAIN, SEEMINGLY IN RESPONSE TO THE DIURNAL CONVECTION THAT WAS NOTED EARLIER. THE INCONSISTENT GUIDANCE THAT HAS DRASTICALLY CHANGED FROM ONE MODEL RUN TO THE NEXT OVER THE LAST 36 HOURS IS SUSPECTED TO BY HIGHLY SENSITIVE TO THE DIURNAL MAXIMUMS THAT WERE REACHED BETWEEN THE 12Z AND 18Z MODEL RUNS, WHICH CAN GIVE THE FALSE IMPRESSION THAT THE SYSTEM IS BECOMING WELL-FORMED. LEADING THE CHARGE ON INTENSIFICATION IS HAFS-A, WHICH PREDICTS A PEAK OF 115KTS AT TAU 108, AND CLOSE BEHIND IS HWRF. GFS AND SHIPS GUIDANCE HAVE BOTH INCREASED TO A PEAK OF 80KTS AT APPROXIMATELY TAU 84. THE JTWC FORECAST DISCOUNTS THE UNTRUSTWORTHY MODEL GUIDANCE AND REMAINS CONSISTENT WITH PREVIOUS FORECASTS. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: HIGH INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
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AXAU01 APRF 180702 IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 0702 UTC 18/03/2024 Name: Tropical Low Identifier: 08U Data At: 0600 UTC Latitude: 17.5S Longitude: 112.6E Location Accuracy: within 30nm (55 km) Movement Towards: west (270 deg) Speed of Movement: 0 knots (1 km/h) Maximum 10-Minute Wind: 30 knots (55 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 998 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T2.0/2.0/S0.0/24HRS STT:S0.0/06HRS Pressure of outermost isobar: 1004 hPa Radius of outermost closed isobar: 210 nm (390 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 18/1200: 17.7S 112.6E: 045 (080): 030 (055): 998 +12: 18/1800: 17.8S 112.5E: 055 (100): 030 (055): 998 +18: 19/0000: 17.9S 112.4E: 060 (110): 030 (055): 998 +24: 19/0600: 17.9S 112.2E: 065 (120): 030 (055): 998 +36: 19/1800: 17.7S 111.4E: 070 (135): 030 (055): 998 +48: 20/0600: 17.5S 110.4E: 085 (155): 030 (055): 999 +60: 20/1800: 17.4S 109.1E: 100 (185): 040 (075): 995 +72: 21/0600: 17.4S 107.4E: 115 (215): 040 (075): 994 +96: 22/0600: 17.6S 103.1E: 145 (270): 050 (095): 990 +120: 23/0600: 18.8S 97.3E: 175 (325): 050 (095): 990 REMARKS: Tropical Low 08U is unlikely to develop significantly until Wednesday, while moving slowly west away from the Australian coast. Position is fair based on animated vis satellite imagery. ASCAT passes at 0128Z and 0220Z show an elongated northwest-southeast circulation. Latest position is at the southeast extreme of that elongated area based on animated vis satellite imagery. Convection continues to fluctuate, with the latest area of deep convection on the southern side of the LLCC. Dvorak analysis: DT is based on weakly curved cold cloud with 0.3 wrap. MET is 2.0 based on a steady 24hr trend. PAT agrees. FT/CI 2.0. Recent objective guidance: ADT 45kn, AiDT 37kn, DPRINT 32kn (all 1-min average). Earlier ASCAT passes showed maximum sustained winds of 25-30 knots. Intensity remains at 30 kn. The environment is not favourable for development in the short term due to surrounding dry air and ~20kn vertical wind shear persisting. The shear is expected to decrease during today and slow intensification is forecast during the mid-week period, reaching tropical cyclone intensity on Wednesday. NWP guidance varies considerably in when intensity begins to increase with some strengthening into a tropical cyclone later today. Further intensification to category 2 later in the week is forecast but there is potential for a severe system as it moves into a more supportive upper environment later in the week. 08U is going through a period of slow motion due to the passage of a mid-level trough to the south causing a break in the mid-level ridge. From Tuesday the sub-tropical ridge is forecast to strengthen, maintaining a steady westerly track at faster speed during the mid-week period. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 18/1330 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 2 pm March 18 tropical low 17.5S 112.6E 55 +6hr 8 pm March 18 tropical low 17.7S 112.6E 80 +12hr 2 am March 19 tropical low 17.8S 112.5E 100 +18hr 8 am March 19 tropical low 17.9S 112.4E 110 +24hr 2 pm March 19 tropical low 17.9S 112.2E 120 +36hr 2 am March 20 tropical low 17.7S 111.4E 135 +48hr 2 pm March 20 tropical low 17.5S 110.4E 155 +60hr 2 am March 21 1 17.4S 109.1E 185 +72hr 2 pm March 21 1 17.4S 107.4E 215 -
WTXS32 PGTW 180900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 029// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 029 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 180600Z --- NEAR 17.0S 112.2E MOVEMENT PAST SIX HOURS - 315 DEGREES AT 03 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 WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER REPEAT POSIT: 17.0S 112.2E --- FORECASTS: 12 HRS, VALID AT: 181800Z --- 17.1S 111.9E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 24 HR POSIT: 300 DEG/ 03 KTS --- 24 HRS, VALID AT: 190600Z --- 16.8S 111.4E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 180900Z POSITION NEAR 17.0S 112.1E. 18MAR24. TROPICAL CYCLONE 18S (EIGHTEEN), LOCATED APPROXIMATELY 336 NM NORTH-NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED NORTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. A 180220Z ASCAT-C SCATTEROMETRY IMAGE REVEALED 25-30 KTS IN THE SOUTHERN PERIPHERY OF THE LOW-LEVEL CIRCULATION CENTER (LLCC) WITH LIGHTER 15-20 KT WINDS AROUND THE NORTHERN PERIPHERY. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS THE OVERALL STRUCTURE OF THE SYSTEM TO BE DISORGANIZED. GLOBAL NUMERICAL MODEL GUIDANCE SUGGESTS THAT THE REMNANTS OF 18S MAY REINTENSIFY IF THE ENVIRONMENTAL CONDITIONS FOR GENESIS IMPROVE. 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. MINIMUM CENTRAL PRESSURE AT 180600Z IS 997 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 180600Z IS 15 FEET.// NNNN
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AXAU01 APRF 181327 IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 1327 UTC 18/03/2024 Name: Tropical Low Identifier: 08U Data At: 1200 UTC Latitude: 17.4S Longitude: 112.4E Location Accuracy: within 30nm (55 km) Movement Towards: northwest (316 deg) Speed of Movement: 3 knots (5 km/h) Maximum 10-Minute Wind: 30 knots (55 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 998 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T2.5/2.5/D0.5/24HRS STT:D0.5/6HRS Pressure of outermost isobar: 1004 hPa Radius of outermost closed isobar: 210 nm (390 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 18/1800: 17.3S 112.3E: 045 (080): 030 (055): 998 +12: 19/0000: 17.2S 112.1E: 055 (100): 030 (055): 998 +18: 19/0600: 17.1S 111.9E: 060 (110): 030 (055): 998 +24: 19/1200: 17.0S 111.6E: 065 (120): 030 (055): 998 +36: 20/0000: 16.8S 110.6E: 065 (120): 030 (055): 999 +48: 20/1200: 16.7S 109.4E: 075 (145): 035 (065): 996 +60: 21/0000: 16.6S 107.7E: 100 (180): 040 (075): 994 +72: 21/1200: 16.6S 106.0E: 115 (210): 045 (080): 992 +96: 22/1200: 17.2S 101.2E: 145 (265): 050 (095): 989 +120: 23/1200: 19.0S 95.6E: 180 (330): 045 (085): 990 REMARKS: Tropical Low 08U has shown signs of intensification during the past 6 hours as deep convection persists south of the LLCC. Position is fair with a broad LLCC evident on recent microwave passes. The convection appears to be co-located with a mid-level circulation centre indicated in animated EIR satellite imagery. AMSR passes at 0500 and 0640UTC indicate a band of 25-30kn winds south of the LLCC under the band of cold cloud. Dvorak analysis: DT=2.5 based on a shear pattern with the LLCC <0.5deg from cold overcast cloud. MET = 2.0 based on a steady 24-hour trend. PAT adjusted up to 2.5 and FT/CI = 2.5. Recent objective guidance: ADT 37kn, AiDT 33kn, DPRINT 34kn (all 1-min average). Intensity remains at 30 kn. The environment has become slightly more favourable for development with a pouch of high TPW around the system and improved outflow to the south ahead of an approaching upper trough. Vertical wind shear has decreased to around 15kn above the circulation, so a gradual intensification is forecast during the next two days, with tropical cyclone development likely by Wednesday. NWP ensemble guidance varies considerably but the consensus is for a high chance of tropical cyclone development on Wednesday northwest of the continent, with further intensification to category 2 or to severe TC intensity possible later in the week over the south Indian Ocean. 08U is currently slow moving due to the passage of a mid-level trough to the south causing a break in the mid-level ridge. From Wednesday the sub-tropical ridge is forecast to strengthen, maintaining a steady west to southwest track at a faster speed later in the week before the system begins to weaken and recurve to the south over the ocean during next weekend. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 18/1930 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 8 pm March 18 tropical low 17.4S 112.4E 55 +6hr 2 am March 19 tropical low 17.3S 112.3E 80 +12hr 8 am March 19 tropical low 17.2S 112.1E 100 +18hr 2 pm March 19 tropical low 17.1S 111.9E 110 +24hr 8 pm March 19 tropical low 17.0S 111.6E 120 +36hr 8 am March 20 tropical low 16.8S 110.6E 120 +48hr 8 pm March 20 tropical low 16.7S 109.4E 145 +60hr 8 am March 21 1 16.6S 107.7E 180 +72hr 8 pm March 21 1 16.6S 106.0E 210 最后于 2024-03-18 21:30:00 被ygsj24编辑 ，原因： -
IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 1949 UTC 18/03/2024 Name: Tropical Low Identifier: 08U Data At: 1800 UTC Latitude: 17.7S Longitude: 112.2E Location Accuracy: within 35nm (65 km) Movement Towards: west southwest (242 deg) Speed of Movement: 2 knots (4 km/h) Maximum 10-Minute Wind: 30 knots (55 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 997 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T2.5/2.5/D0.5/24HRS STT:S0.0/06HRS Pressure of outermost isobar: 1004 hPa Radius of outermost closed isobar: 160 nm (295 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 19/0000: 17.6S 112.0E: 045 (080): 030 (055): 998 +12: 19/0600: 17.5S 111.8E: 050 (095): 030 (055): 998 +18: 19/1200: 17.4S 111.6E: 055 (105): 030 (055): 998 +24: 19/1800: 17.3S 111.1E: 060 (110): 030 (055): 998 +36: 20/0600: 17.3S 109.9E: 065 (125): 030 (055): 999 +48: 20/1800: 17.2S 108.4E: 080 (150): 040 (075): 994 +60: 21/0600: 17.3S 106.7E: 095 (170): 045 (085): 991 +72: 21/1800: 17.2S 104.7E: 105 (200): 045 (085): 991 +96: 22/1800: 17.8S 99.4E: 135 (250): 050 (095): 989 +120: 23/1800: 19.6S 94.2E: 165 (305): 045 (085): 990 REMARKS: Tropical Low 08U is near stationary well northwest of the Pilbara coast. Position is fair to poor based on EIR animated imagery and a recent microwave imagery. Dvorak analysis: DT is based on a 0.4 wrap. The 24h trend is steady with MET 2.0, and PAT adjusted to 2.5. The FT 2.5 is based on the DT and PAT. CI is 2.5. Recent objective guidance: ADT 33kn, AiDT 31kn, DPRINT 33kn, DMINT 29kn (all 1-min average) (SATCON N/A). Intensity is set at 30 kn which in line with the objective guidance and Dvorak analysis. The vertical wind has been moderate to strong northeasterly, though may have eased slightly over the last few hours. Environment is not favourable for development in the short term due to surrounding dry air. The forecast shear could decrease over the coming days and slow intensification is forecast during the mid-week period. Some NWP guidance indicates further intensification to category 2 later in the week as the system moves west across the southern Indian Ocean into a slightly more supportive upper environment. 08U has been moving to the west under the influence of a weak steering ridge to the south. This westward movement is expected to stall for 24-36 hours due to the passage of a mid-level trough to the south. From Tuesday the sub-tropical ridge is forecast to strengthen, maintaining a steady westerly track at faster speed during the mid-week period. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 19/0130 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 2 am March 19 tropical low 17.7S 112.2E 65 +6hr 8 am March 19 tropical low 17.6S 112.0E 80 +12hr 2 pm March 19 tropical low 17.5S 111.8E 95 +18hr 8 pm March 19 tropical low 17.4S 111.6E 105 +24hr 2 am March 20 tropical low 17.3S 111.1E 110 +36hr 2 pm March 20 tropical low 17.3S 109.9E 125 +48hr 2 am March 21 1 17.2S 108.4E 150 +60hr 2 pm March 21 1 17.3S 106.7E 170 +72hr 2 am March 22 1 17.2S 104.7E 200 -
AXAU01 APRF 190055 IDW27600 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 0055 UTC 19/03/2024 Name: Tropical Low Identifier: 08U Data At: 0000 UTC Latitude: 18.3S Longitude: 112.1E Location Accuracy: within 30nm (55 km) Movement Towards: south southwest (202 deg) Speed of Movement: 4 knots (7 km/h) Maximum 10-Minute Wind: 30 knots (55 km/h) Maximum 3-Second Wind Gust: 45 knots (85 km/h) Central Pressure: 999 hPa Radius of 34-knot winds NE quadrant: Radius of 34-knot winds SE quadrant: Radius of 34-knot winds SW quadrant: Radius of 34-knot winds NW quadrant: Radius of 48-knot winds NE quadrant: Radius of 48-knot winds SE quadrant: Radius of 48-knot winds SW quadrant: Radius of 48-knot winds NW quadrant: Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: nm ( km) Dvorak Intensity Code: T2.5/2.5/D0.5/24HRS STT:S0.0/06HRS Pressure of outermost isobar: 1005 hPa Radius of outermost closed isobar: 160 nm (295 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 19/0600: 18.0S 111.7E: 045 (085): 030 (055): 998 +12: 19/1200: 17.9S 111.3E: 055 (100): 030 (055): 998 +18: 19/1800: 17.6S 110.8E: 055 (105): 030 (055): 998 +24: 20/0000: 17.4S 110.2E: 060 (105): 030 (055): 999 +36: 20/1200: 17.3S 108.9E: 060 (115): 030 (055): 998 +48: 21/0000: 17.3S 107.3E: 075 (135): 040 (075): 994 +60: 21/1200: 17.3S 105.4E: 090 (160): 045 (085): 991 +72: 22/0000: 17.2S 103.1E: 095 (180): 045 (085): 992 +96: 23/0000: 18.2S 97.3E: 120 (225): 050 (095): 988 +120: 24/0000: 20.2S 91.9E: 160 (300): 040 (075): 992 REMARKS: Tropical Low 08U is very slow moving well northwest of the Pilbara coast. Position is fair to poor based on animated Vis imagery. Dvorak analysis: DT is based on a 0.4 wrap. The 24h trend is D- with MET 2.5, and PAT 2.5. The FT 2.5 is based on the DT and PAT. CI is 2.5. Recent objective guidance: ADT 32kn, AiDT 31kn, DPRINT 36kn (all 1-min average) (SATCON N/A). Intensity is set at 30 kn which in line with the objective guidance and Dvorak analysis. The vertical wind has been moderate to strong northeasterly, though may have eased a little further over the last few hours. The environment is not particularly favourable for development in the short term due to surrounding dry air. The forecast shear could decrease over the coming days and slow intensification is forecast during the mid-week period. Some NWP guidance indicates further intensification to category 2, or a small chance of higher, later in the week, as the system moves west across the southern Indian Ocean into a slightly more supportive upper environment. 08U has been moving generally to the west under the influence of a weak steering ridge to the south. This westward movement is expected to stall for 12 to 24 hours due to the passage of a mid-level trough to the south and the recent southerly component to the systems motion may be influenced by this. From later today the sub-tropical ridge is forecast to strengthen, maintaining a steady westerly track at faster speed during the mid-week period. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 19/0730 UTC.
Time (AWST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 8 am March 19 tropical low 18.3S 112.1E 55 +6hr 2 pm March 19 tropical low 18.0S 111.7E 85 +12hr 8 pm March 19 tropical low 17.9S 111.3E 100 +18hr 2 am March 20 tropical low 17.6S 110.8E 105 +24hr 8 am March 20 tropical low 17.4S 110.2E 105 +36hr 8 pm March 20 tropical low 17.3S 108.9E 115 +48hr 8 am March 21 1 17.3S 107.3E 135 +60hr 8 pm March 21 1 17.3S 105.4E 160 +72hr 8 am March 22 1 17.2S 103.1E 180 -
ABIO10 PGTW 190600 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN REISSUED/190600Z-191800ZMAR2024// RMKS/ 1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA): A. TROPICAL CYCLONE SUMMARY: NONE. B. TROPICAL DISTURBANCE SUMMARY: NONE. C. SUBTROPICAL SYSTEM SUMMARY: NONE. 2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA): A. TROPICAL CYCLONE SUMMARY: NONE. B. TROPICAL DISTURBANCE SUMMARY: (1) AN AREA OF CONVECTION (REMNANTS 18S) HAS PERSISTED NEAR 18.1S 111.8E, APPROXIMATELY 275 NM NORTH-NORTHWEST OF LEARMONTH, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY REVEALS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC), WITH A WELL- ORGANIZED UPPER-LEVEL CIRCULATION CENTER POSITIONED SLIGHTLY TO THE SOUTH. A 190156Z MHS 89 GHZ MICROWAVE IMAGE INDICATES CURVED DEEP CONVECTIVE BANDING OVER THE SOUTHERN AND WESTERN QUADRANTS WITH NO DEEP CONVECTION OVER THE EASTERN QUADRANT DUE TO DRY AIR ENTRAINMENT. A PARTIAL 190108Z ASCAT-B IMAGE INDICATES 25-30 KNOT WINDS OVER THE SOUTHERN SEMICIRCLE. ENVIRONMENTAL CONDITIONS ARE MARGINALLY-FAVORABLE DUE PRIMARILY TO EXTENSIVE DRY AIR ENTRAINMENT IN THE MID- TO UPPER- LEVELS, OFFSET BY LOW VWS, ROBUST POLEWARD VENTING, AND WARM SST (27- 28 C). GLOBAL MODELS INDICATE THE SYSTEM WILL REINTENSIFY AS IT TRACKS WESTWARD OVER THE NEXT TWO DAYS, BUT VARY SIGNIFICANTLY ON THE TIMING OF THE REDEVELOPMENT OF A TROPICAL STORM STRENGTH SYSTEM. GFS INDICATES REDEVELOPMENT WITHIN THE NEXT TWO DAYS WHILE ECMWF INDICATES A LESS AGGRESSIVE 2-3 DAY REDEVELOPMENT TIMELINE. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM. (2) NO OTHER SUSPECT AREAS. C. SUBTROPICAL SYSTEM SUMMARY: NONE. 3. JUSTIFICATION FOR REISSUE: REMOVED TROPICAL CYCLONE (TC) 18S FINAL WARNING INFORMATION AND ADDED REMNANTS OF TC 18S AS A MEDIUM.// NNNN
