最新回复 (51)
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SSD 5.0
TXPS26 KNES 170602
TCSWSP
A. 19P (MEGAN)
B. 17/0530Z
C. 15.1S
D. 137.2E
E. THREE/HIMAWARI-9
F. T5.0/5.0
G. IR/EIR/VIS
H. REMARKS...LLCC EMBEDDED IN CMG RESULTS IN A DT OF 5.0. MET IS 4.0
BASED ON A RAPID 24-HOUR DEVELOPING TREND. PT IS 4.5. THE FT IS BASED
ON THE DT.
I. ADDL POSITIONS
NIL
...CLARK
TPPS10 PGTW 170619
A. TROPICAL CYCLONE 19P (MEGAN)
B. 17/0550Z
C. 15.02S
D. 137.05E
E. FIVE/GK2A
F. T4.5/4.5/D1.5/24HRS STT: D0.5/03HRS
G. IR/EIR/VIS/MSI
H. REMARKS: 40A/PBO SBC/ANMTN. LLCC EMBEDDED IN CMG YIELDS A DT OF
5.0. MET YIELDS 4.0. PT YIELDS 4.5. DBO PT.
I. ADDITIONAL POSITIONS: NONE
FLEWALLEN
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AXAU01 ADRM 170700 IDD20020 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 0700 UTC 17/03/2024 Name: Severe Tropical Cyclone Megan Identifier: 09U Data At: 0600 UTC Latitude: 15.0S Longitude: 137.1E Location Accuracy: within 15nm (30 km) Movement Towards: south southwest (209 deg) Speed of Movement: 4 knots (7 km/h) Maximum 10-Minute Wind: 65 knots (120 km/h) Maximum 3-Second Wind Gust: 90 knots (165 km/h) Central Pressure: 973 hPa Radius of 34-knot winds NE quadrant: 90 nm (165 km) Radius of 34-knot winds SE quadrant: 60 nm (110 km) Radius of 34-knot winds SW quadrant: 60 nm (110 km) Radius of 34-knot winds NW quadrant: 80 nm (150 km) Radius of 48-knot winds NE quadrant: 50 nm (95 km) Radius of 48-knot winds SE quadrant: 40 nm (75 km) Radius of 48-knot winds SW quadrant: 40 nm (75 km) Radius of 48-knot winds NW quadrant: 40 nm (75 km) Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: 20 nm (35 km) Dvorak Intensity Code: T4.5/4.5/D1.5/24HRS STT:D0.5/06HRS Pressure of outermost isobar: 1002 hPa Radius of outermost closed isobar: 200 nm (370 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 17/1200: 15.2S 137.0E: 030 (060): 070 (130): 969 +12: 17/1800: 15.4S 137.0E: 045 (080): 075 (140): 965 +18: 18/0000: 15.6S 137.0E: 055 (100): 080 (150): 960 +24: 18/0600: 15.8S 136.9E: 065 (115): 080 (150): 960 +36: 18/1800: 16.1S 136.4E: 085 (155): 050 (095): 984 +48: 19/0600: 16.4S 135.6E: 100 (180): 035 (065): 994 +60: 19/1800: 16.5S 134.4E: 115 (215): 030 (055): 997 +72: 20/0600: 16.4S 133.0E: 130 (235): 025 (045): 999 +96: 21/0600: 16.0S 130.0E: 165 (300): 020 (035): 1000 +120: 22/0600: 15.9S 127.5E: 200 (370): 020 (035): 1001 REMARKS: Severe Tropical Cyclone Megan continues to intensify over the southwestern Gulf of Carpentaria. Banding in the central dense overcast has improved during the day, and a marginal, intermittent eye-like feature has been visible in the IR satellite imagery at times. Confidence in the centre position is good based on satellite imagery plus Gove and Mornington Island radars. Dvorak analysis: DT based on a 3 hour average of curved band patterns with 1.1 to 1.3 wraps. 0.5 added to T number for white or colder bands to give DT4.5. MET is also 4.5 based on a 24 hour D+ trend, however PT is adjusted down to 4.0. FT = CI = 4.5. Objective aids are: ADT 79kt, AiDT 77kt, DPRINT 80kt, DMINT 77kt, SATCON 69kt and MW Sounders 59kt (all 1-min average). Intensity is analysed at 65 knots based on a combination of subjective Dvorak, objective aids, and model guidance. Motion over the past 6 hours has been more to the southwest, although it is possible this is a shorter term trochoidal oscillation, with longer term average motion remaining to the south-southwest. Mid-level ridging to the east and to a lesser extent to the south appear to be the dominant steering influences. This should see the system continue on a slow south-southwest track until it crosses the southwestern Gulf of Carpentaria coast. There remains uncertainty in the timing of this crossing, with guidance spread across the interval from tonight to Tuesday morning. Beyond that, the mid-level ridge to the south is expected to strengthen and steer the system west across inland parts of the Northern Territory as a tropical low through the remainder of the week. Tropical Cyclone Megan has developed against moderate easterly wind shear, currently estimated at around 15-20 knots from CIMSS upper wind analysis. This has been offset by otherwise favourable conditions; abundant low and mid-level moisture, and high SSTs (30-31C) over the Gulf of Carpentaria. 03UTC CIMSS upper winds show good outflow persisting in the southern quadrants, though upper northerlies are beginning to encroach on the northern side of the system due to an upper anticyclone strengthening to the east. The forecast track should move the system further into the lighter shear regime over the next 24 hours, and a standard rate of development is therefore forecast to continue. This would see Megan reach high category 3 intensity prior to forecast landfall on Monday. However this comes with uncertainty. On one hand, a period of rapid intensification cannot be ruled out given the favourable atmospheric conditions along the forecast track. Another scenario, however, is the system moving more quickly and hence moving closer to land earlier, in which case it will have less time to develop and the landfall intensity may be lower. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 17/1330 UTC.
Time (ACST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 4 pm March 17 3 15.0S 137.1E 30 +6hr 10 pm March 17 3 15.2S 137.0E 60 +12hr 4 am March 18 3 15.4S 137.0E 80 +18hr 10 am March 18 3 15.6S 137.0E 100 +24hr 4 pm March 18 3 15.8S 136.9E 115 +36hr 4 am March 19 2 16.1S 136.4E 155 +48hr 4 pm March 19 tropical low 16.4S 135.6E 180 +60hr 4 am March 20 tropical low 16.5S 134.4E 215 +72hr 4 pm March 20 tropical low 16.4S 133.0E 235 -
全球热带气旋监测公报
“梅甘”加强为三级强热带气旋
时 间：17日14时（北京时）
海 域：澳大利亚附近海域
命 名：“梅甘”，MEGAN
中心位置：南纬15.0度、东经137.1度
强度等级：三级强热带气旋
最大风力：12级（33米/秒，相当于我国的台风级）
中心气压：973百帕
参考位置：澳大利亚昆士兰州汤斯维尔西偏北方向约1140公里的洋面上
变化过程：过去24小时，“梅甘”由10级加强到12级
预报结论：“梅甘”将以每小时5-10公里的速度向南偏西方向缓慢移动，强度还将略有增强。
图1 卫星红外监测图像（北京时间2024年03月17日14时00分）
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WTPS31 PGTW 170900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 19P (MEGAN) WARNING NR 008// RMKS/ 1. TROPICAL CYCLONE 19P (MEGAN) WARNING NR 008 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 170600Z --- NEAR 15.0S 137.0E MOVEMENT PAST SIX HOURS - 270 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE, RADAR AND SYNOPTIC DATA PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT REPEAT POSIT: 15.0S 137.0E --- FORECASTS: 12 HRS, VALID AT: 171800Z --- 15.5S 136.8E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 000 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 225 DEG/ 02 KTS --- 24 HRS, VALID AT: 180600Z --- 15.8S 136.5E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 235 DEG/ 04 KTS --- 36 HRS, VALID AT: 181800Z --- 16.2S 135.9E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 250 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 190600Z --- 16.5S 135.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 72 HR POSIT: 265 DEG/ 07 KTS --- 72 HRS, VALID AT: 200600Z --- 16.6S 132.2E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 170900Z POSITION NEAR 15.1S 137.0E. 17MAR24. TROPICAL CYCLONE 19P (MEGAN), LOCATED APPROXIMATELY 386 NM EAST-SOUTHEAST OF DARWIN, AUSTRALIA, HAS TRACKED WESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 170600Z IS 962 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 170600Z IS 25 FEET. NEXT WARNINGS AT 171500Z, 172100Z, 180300Z AND 180900Z.// NNNN
WDPS31 PGTW 170900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19P (MEGAN) WARNING NR 008// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 15.0S 137.0E INITIAL INTENSITY: 85 KTS GEOGRAPHIC REFERENCE: 386 NM EAST-SOUTHEAST OF DARWIN, AUSTRALIA MOVEMENT PAST 6 HOURS: WESTWARD AT 04 KTS SIGNIFICANT WAVE HEIGHT: 25 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL CYCLONE (TC) 19P (MEGAN) EXHIBITING A VERY EXPANSIVE CENTRAL DENSE OVERCAST FEATURE OBSCURING NEARLY ALL OF THE GULF OF CARPENTARIA AS WELL AS THE STORMS ASSESSED LOW-LEVEL CIRCULATION CENTER. 170417Z AMSR2 37GHZ AND 89GHZ SATELLITE MICROWAVE IMAGERY AND RADAR DATA REVEALED THE SYSTEM HAS A COMPLETE EYE STRUCTURE THAT IS LIKELY BEING COVERED IN VISIBLE IMAGERY DUE TO THE ROBUST CENTRAL CONVECTION OVER THE PAST SIX HOURS WITH AN ASSESSED POINT SOURCE ALOFT COLLOCATED OVERHEAD THE LLCC. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON EXTRAPOLATION OF THE AFOREMENTIONED AMSR2 SATELLITE MICROWAVE IMAGES AND RADAR DATA. THE INITIAL INTENSITY OF 85 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE RISE OF SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES LISTED BELOW. INITIAL WIND RADII BASIS: 170417Z AMSR2 WINDSPEED IMAGE AND SURFACE OBSERVATIONS CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A WEAK NEAR EQUATORIAL RIDGE (NER) TO THE EAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.5 - 77 KTS KNES: T5.0 - 90 KTS CIMSS SATCON: 83 KTS AT 170700Z CIMSS ADT: 82 KTS AT 170730Z CIMSS DPRINT: 83 KTS AT 170600Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE EQUATORWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 19P (MEGAN) IS FORECAST TO TRACK SOUTH-SOUTHWESTWARD (TAU 00 TO TAU 12) TO SOUTHWESTWARD (TAU 12 TO 36) FOLLOWING THE STEERING INFLUENCE OF A WEAK NER TO THE EAST. PRIOR TO LANDFALL NEAR TAU 24, A FAVORABLE ENVIRONMENT HAVING LOW (10-15KTS) VERTICAL WIND SHEAR (VWS), VERY WARM (30-31C) SEA SURFACE TEMPERATURES (SST), AND IMPROVING OUTFLOW ALOFT (COLLOCATED WITH UPPER-LEVEL POINT SOURCE) LEAVES ROOM FOR FURTHER INTENSIFICATION TO OCCUR THROUGH TAU 12. ONCE INTERACTION WITH LAND AND FRICTIONAL COMPONENTS BEGIN TO IMPACT THE STORM, A RAPID WEAKENING TREND IS ANTICIPATED TO START NEAR TAU 12 AND CONTINUE THROUGH TAU 72 AS THE SYSTEM TRACKS INLAND. SHORTLY AFTER TAU 36 THE PRIMARY STEERING INFLUENCE IS EXPECTED TO SHIFT FROM THE PREVIOUSLY MENTIONED NER TO A STR OVER CENTRAL AUSTRALIA AND STEER THE SYSTEM WESTWARD THROUGH TAU 72. DISSIPATION IS FORECAST TO BE COMPLETE BY TAU 72 OVER NORTHERN AUSTRALIA. MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE IS IN OVERALL GOOD AGREEMENT OVER THE DURATION OF THE FORECAST INTERVAL, WITH THE MOST SIGNIFICANT UNCERTAINTY BEING TRACK SPEED BETWEEN TAU 00 AND TAU 36. THE CROSS-TRACK SPREAD AMONG JTWC CONSENSUS MEMBERS IS 56NM BETWEEN ECMWF ENSEMBLE MEAN (WESTERN-MOST) AND GALWEM (EASTERN-MOST) BY TAU 36, WITH A HIGHER ALONG TRACK SPREAD OF 102NM BETWEEN GFS (SOUTHERN-MOST) AND GALWEM (NORTHERN-MOST) OVER THE SAME INTERVAL. THE CROSS TRACK SPREAD MORE THAN DOUBLES TO 135NM BY TAU 72. THE INTENSITY FORECAST, LIKELY DUE TO A SLIGHTLY HIGHER THAN ANTICIPATED TRACK SPEED OVER THE PAST 12 HOURS, HAS SHIFTED PEAK INTENSITY TO OCCUR EARLIER IN TIME (TAU 12) THAN PREVIOUSLY FORECAST. STATISTICAL- DYNAMICAL GUIDANCE OVERSHOOTS THE JTWC INTENSITY FORECAST, WHILE MESOSCALE AND GLOBAL MODEL SOLUTIONS COME IN JUST UNDER THE FORECAST. THE OVERALL GOOD AGREEMENT WITH SOME UNCERTAINTY PRESENTED CONTRIBUTES TO THE OVERALL FORECAST CONFIDENCE OF MEDIUM. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM// NNNN
最后于 2024-03-17 18:00:00 被ygsj24编辑 ，原因： -
AXAU01 ADRM 171323 IDD20020 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 1323 UTC 17/03/2024 Name: Severe Tropical Cyclone Megan Identifier: 09U Data At: 1200 UTC Latitude: 15.1S Longitude: 137.1E Location Accuracy: within 15nm (30 km) Movement Towards: southwest (224 deg) Speed of Movement: 2 knots (4 km/h) Maximum 10-Minute Wind: 70 knots (130 km/h) Maximum 3-Second Wind Gust: 100 knots (185 km/h) Central Pressure: 967 hPa Radius of 34-knot winds NE quadrant: 90 nm (165 km) Radius of 34-knot winds SE quadrant: 60 nm (110 km) Radius of 34-knot winds SW quadrant: 60 nm (110 km) Radius of 34-knot winds NW quadrant: 80 nm (150 km) Radius of 48-knot winds NE quadrant: 50 nm (95 km) Radius of 48-knot winds SE quadrant: 40 nm (75 km) Radius of 48-knot winds SW quadrant: 40 nm (75 km) Radius of 48-knot winds NW quadrant: 40 nm (75 km) Radius of 64-knot winds: nm ( km) Radius of Maximum Winds: 15 nm (30 km) Dvorak Intensity Code: T4.0/4.5/D0.5/24HRS STT:W0.5/06HRS Pressure of outermost isobar: 1002 hPa Radius of outermost closed isobar: 200 nm (370 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 17/1800: 15.3S 137.0E: 030 (055): 075 (140): 965 +12: 18/0000: 15.5S 137.0E: 045 (080): 075 (140): 964 +18: 18/0600: 15.7S 136.9E: 055 (100): 075 (140): 965 +24: 18/1200: 15.8S 136.7E: 065 (120): 065 (120): 973 +36: 19/0000: 16.4S 135.9E: 080 (150): 040 (075): 991 +48: 19/1200: 16.6S 135.0E: 100 (185): 030 (055): 997 +60: 20/0000: 16.7S 133.5E: 115 (210): 025 (045): 999 +72: 20/1200: 16.4S 132.1E: 125 (230): 025 (045): 999 +96: 21/1200: 15.6S 129.0E: 160 (290): 020 (035): 1002 +120: 22/1200: 15.6S 126.3E: 200 (375): 020 (035): 1002 REMARKS: Severe Tropical Cyclone Megan has intensified over the last 6-12 hours and may continue to do so as it approaches the southwest coast of the Gulf of Carpentaria. Confidence in the centre position is good based on satellite imagery and the Mornington Island radar. Intensity is analysed at 70 knots based on a combination of subjective Dvorak and objective aids. Dvorak analysis: with the loss of visible imagery Dvorak analysis has become more difficult and over the last three hours the FT has been biased towards MET/PAT. A trend of S was applied giving a MET of 3.5 with PAT adjusted up to 4.0. FT is 4.0 with CI held at 4.5. Objective aids are: ADT 82kt, AiDT 77 kt, DPRINT 78kt, SATCON 68kt (all 1-min average). Motion over the past 6 hours has been very slowly southwest. Mid-level ridging to the east and to a lesser extent to the south appear to be the dominant steering influences. This should see the system continue on a slow south-southwest track until it crosses the southwestern Gulf of Carpentaria coast. There remains uncertainty in the timing of this crossing, with guidance spread across the interval from Monday morning to Tuesday morning. Beyond that, the mid-level ridge to the south is expected to strengthen and steer the system west across inland parts of the Northern Territory as a tropical low through the remainder of the week. The wind shear near Megan is currently estimated at around 27 knots northeasterly from CIMSS upper wind analysis. The strong wind shear has been offset by otherwise favourable conditions; abundant low and mid-level moisture, and high SSTs (30-31C) over the Gulf of Carpentaria. There has been good outflow in the southern quadrants however the 09UTC CIMSS analyses show poor upper divergence over the system. There is a high degree of uncertainty around the maximum intensity Megan may reach prior to landfall. Model guidance suggests Megan may currently be near peak intensity with nearly all guidance indicating a decreasing trend in maximum wind speeds from 1200 UTC 17 March. However a period of rapid intensification cannot be ruled out with RIPA and FRIA indicating about a 30% chance of intensification of 25 kt over 24 hours. Another scenario, however, is the system moving more quickly and hence moving closer to land earlier, in which case it will have less time to develop and the landfall intensity may be lower. Currently the forecast track increases the intensity to 75 knots over the next 12 hours and then decreases it as the system makes landfall. Once over land Megan should weaken quickly below tropical cyclone strength. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 17/1930 UTC.
Time (ACST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 10 pm March 17 3 15.1S 137.1E 30 +6hr 4 am March 18 3 15.3S 137.0E 55 +12hr 10 am March 18 3 15.5S 137.0E 80 +18hr 4 pm March 18 3 15.7S 136.9E 100 +24hr 10 pm March 18 3 15.8S 136.7E 120 +36hr 10 am March 19 1 16.4S 135.9E 150 +48hr 10 pm March 19 tropical low 16.6S 135.0E 185 +60hr 10 am March 20 tropical low 16.7S 133.5E 210 +72hr 10 pm March 20 tropical low 16.4S 132.1E 230 -
WTPS31 PGTW 171500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 19P (MEGAN) WARNING NR 009// RMKS/ 1. TROPICAL CYCLONE 19P (MEGAN) WARNING NR 009 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 171200Z --- NEAR 14.9S 137.3E MOVEMENT PAST SIX HOURS - 070 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE, RADAR AND SYNOPTIC DATA PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT REPEAT POSIT: 14.9S 137.3E --- FORECASTS: 12 HRS, VALID AT: 180000Z --- 15.4S 137.1E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 225 DEG/ 03 KTS --- 24 HRS, VALID AT: 181200Z --- 15.8S 136.7E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 235 DEG/ 05 KTS --- 36 HRS, VALID AT: 190000Z --- 16.3S 135.9E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 000 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 260 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 191200Z --- 16.5S 134.9E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 72 HR POSIT: 275 DEG/ 07 KTS --- 72 HRS, VALID AT: 201200Z --- 16.3S 132.0E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 171500Z POSITION NEAR 15.0S 137.3E. 17MAR24. TROPICAL CYCLONE 19P (MEGAN), LOCATED APPROXIMATELY 400 NM EAST-SOUTHEAST OF DARWIN, AUSTRALIA, HAS TRACKED EAST- NORTHEASTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 171200Z IS 957 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 171200Z IS 29 FEET. NEXT WARNINGS AT 172100Z, 180300Z, 180900Z AND 181500Z.// NNNN
WDPS31 PGTW 171500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19P (MEGAN) WARNING NR 009// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 14.9S 137.3E INITIAL INTENSITY: 95 KTS GEOGRAPHIC REFERENCE: 400 NM EAST-SOUTHEAST OF DARWIN, AUSTRALIA MOVEMENT PAST 6 HOURS: EAST-NORTHEASTWARD AT 03 KTS SIGNIFICANT WAVE HEIGHT: 29 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL CYCLONE (TC) 19P (MEGAN) EXHIBITING TROCHOIDAL MOTION AS THE SYSTEM TRACKED GENERALLY EAST-NORTHEASTWARD OVER THE PAST SIX HOURS, BACKTRACKING OVER PREVIOUSLY TRAVELED WATERS. A 170844Z SSMIS 37GHZ SATELLITE MICROWAVE IMAGE CAPTURED A WELL-DEFINED MICROWAVE EYE, WITH THE CORRESPONDING 89GHZ IMAGE SUGGESTING THE TC VORTEX IS WELL ALIGNED VERTICALLY. A RCM-3 SYNTHETIC APERTURE RADAR (SAR) IMAGE OF 170919Z REPORTED UP TO 123KTS IN THE NORTHWEST QUADRANT OF THE SYSTEM AND AS LOW AS 92KTS IN THE SOUTHWEST QUADRANT. HOWEVER, A 45 DEGREE INCIDENCE ANGLE TO THE COLLECTING SENSOR MAY HAVE POSITIVELY SKEWED REPORTED VALUES. THE INITIAL POSITION AND INTENSITY OF 95 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AFOREMENTIONED SAR IMAGE AND THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES LISTED BELOW. INITIAL WIND RADII BASIS: SAR DATA CURRENT STEERING MECHANISM: WEAK NER EXTENSION TO THE NORTHEAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.0 - 90 KTS KNES: T5.0 - 90 KTS CIMSS ADT: 82 KTS AT 171200Z CIMSS AIDT: 78 KTS AT 171200Z CIMSS DPRINT: 78 KTS AT 171200Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 15-20 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 19P (MEGAN) IS FORECAST TO TRACK SOUTH-SOUTHWESTWARD (TAU 00 TO TAU 12) TO SOUTHWESTWARD (TAU 12 TO 36) FOLLOWING THE STEERING INFLUENCE OF A WEAK NER TO THE NORTHEAST. PRIOR TO LANDFALL NEAR TAU 24, A FAVORABLE ENVIRONMENT HAVING LOW TO MODERATE (10-20KTS) VERTICAL WIND SHEAR (VWS), VERY WARM (30-31C) SEA SURFACE TEMPERATURES (SST), AND MODERATE POLEWARD OUTFLOW ALOFT (COLLOCATED WITH UPPER-LEVEL POINT SOURCE) LEAVES ROOM FOR FURTHER INTENSIFICATION TO OCCUR THROUGH TAU 06. ONCE INTERACTION WITH LAND AND FRICTIONAL COMPONENTS BEGIN TO IMPACT THE STORM, A RAPID WEAKENING TREND IS ANTICIPATED TO START AT OR PRIOR TO TAU 06 AND CONTINUE THROUGH TAU 72 AS THE SYSTEM TRACKS INLAND. SHORTLY AFTER TAU 36 THE PRIMARY STEERING INFLUENCE IS EXPECTED TO SHIFT FROM THE PREVIOUSLY MENTIONED NER TO A STR OVER CENTRAL AUSTRALIA AND STEER THE SYSTEM WESTWARD THROUGH TAU 72. DISSIPATION IS FORECAST TO BE COMPLETE BY TAU 72 OVER NORTHERN AUSTRALIA. MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE IS IN OVERALL GOOD AGREEMENT OVER THE DURATION OF THE FORECAST INTERVAL, WITH THE MOST SIGNIFICANT UNCERTAINTY BEING TRACK SPEED BETWEEN TAU 00 AND TAU 36. DISREGARDING NAVGEM TRACKING WESTWARD FROM TAU 00 TO TAU 72, THE CROSS-TRACK SPREAD AMONG JTWC CONSENSUS MEMBERS IS 71NM BY TAU 36, WITH A HIGHER ALONG TRACK SPREAD OF 93NM OVER THE SAME INTERVAL. BY TAU 72, THE CROSS-TRACK SPREAD BETWEEN ALL JTWC CONSENSUS MEMBERS IS 109NM. OVERALL, INTENSITY GUIDANCE SUGGESTS TC 19P HAS OR WILL REACH PEAK INTENSITY BY TAU 06 WITH A DOWNTREND AND WEAKENING THEREAFTER TO TAU 72. STATISTICAL-DYNAMICAL GUIDANCE (SHIPS) IS THE ONLY OUTLIER AMONG INTENSITY CONSENSUS MEMBERS, AND SOLELY SUGGESTS A CONTINUED INTENSIFICATION PERIOD THROUGH TAU 12, FOLLOWED BY A DOWNTREND TO TAU 72. THE OVERALL GOOD AGREEMENT WITH SOME UNCERTAINTY PRESENTED CONTRIBUTES TO THE OVERALL FORECAST CONFIDENCE OF MEDIUM. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM// NNNN
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AXAU01 ADRM 171901 IDD20020 TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE at: 1901 UTC 17/03/2024 Name: Severe Tropical Cyclone Megan Identifier: 09U Data At: 1800 UTC Latitude: 15.2S Longitude: 137.2E Location Accuracy: within 15nm (30 km) Movement Towards: south southwest (198 deg) Speed of Movement: 2 knots (3 km/h) Maximum 10-Minute Wind: 70 knots (130 km/h) Maximum 3-Second Wind Gust: 100 knots (185 km/h) Central Pressure: 970 hPa Radius of 34-knot winds NE quadrant: 90 nm (165 km) Radius of 34-knot winds SE quadrant: 70 nm (130 km) Radius of 34-knot winds SW quadrant: 60 nm (110 km) Radius of 34-knot winds NW quadrant: 90 nm (165 km) Radius of 48-knot winds NE quadrant: 50 nm (95 km) Radius of 48-knot winds SE quadrant: 40 nm (75 km) Radius of 48-knot winds SW quadrant: 40 nm (75 km) Radius of 48-knot winds NW quadrant: 50 nm (95 km) Radius of 64-knot winds: 30 nm (55 km) Radius of Maximum Winds: 15 nm (30 km) Dvorak Intensity Code: T4.0/4.5/S0.0/24HRS STT: S0.0/06HRS Pressure of outermost isobar: 1002 hPa Radius of outermost closed isobar: 200 nm (370 km) FORECAST DATA Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure (UTC) : degrees : nm (km): knots(km/h): hPa +06: 18/0000: 15.6S 137.1E: 035 (065): 075 (140): 967 +12: 18/0600: 15.8S 137.1E: 050 (090): 070 (130): 969 +18: 18/1200: 16.0S 136.9E: 060 (110): 060 (110): 983 +24: 18/1800: 16.3S 136.6E: 070 (125): 050 (095): 988 +36: 19/0600: 16.8S 135.8E: 080 (150): 030 (055): 1000 +48: 19/1800: 16.9S 134.7E: 095 (180): 025 (045): 1001 +60: 20/0600: 16.7S 133.3E: 115 (215): 025 (045): 1000 +72: 20/1800: 16.4S 131.6E: 135 (250): 025 (045): 1000 +96: 21/1800: 15.6S 128.9E: 170 (320): 020 (035): 1001 +120: 22/1800: 15.7S 126.2E: 215 (395): 020 (035): 1002 REMARKS: Severe Tropical Cyclone Megan remains at category 3 intensity while slowly tracking towards the southwestern Gulf of Carpentaria coast. Confidence in the centre position is good based on Mornington Island radar imagery. Intensity is analysed at 70 knots based on a combination of subjective Dvorak and objective aids. Dvorak analysis: an embedded centre pattern with a white or colder surrounding grey shade has been applied in the last few hours, giving a DT of 5.0. A trend of S was applied giving a MET of 3.5 with PAT adjusted up to 4.0. FT is 4.0 with CI held at 4.5. Objective aids are: ADT 82kt, AiDT 84 kt, DPRINT 86kt, SATCON 78kt (all 1-min average). Motion has been near stationary for most of the night, though in the last few hours the system appears to have started tracking towards the south southwest in the direction of the southwestern Gulf of Carpentaria coast. Mid-level ridging to the east and to a lesser extent to the south appear to be the dominant steering influences. This should see the system continue on a slow south-southwest track until it crosses the southwestern Gulf of Carpentaria coast later today. Beyond that, the mid-level ridge to the south is expected to strengthen and steer the system west across inland parts of the Northern Territory as a tropical low through the remainder of the week. The wind shear near Megan is currently northeasterly at around 20 to 25 knots from CIMSS upper wind analysis. The strong wind shear has been offset by otherwise favourable conditions; abundant low and mid-level moisture, good poleward outflow and high SSTs (30-31C) over the Gulf of Carpentaria. Model guidance suggests Megan may currently be near peak intensity with nearly all guidance indicating a decreasing trend in maximum wind speeds. The current forecast scenario sees a slight intensification in the system before landfall, though this equally may not occur given its near steady development overnight and limited amount of time before it crosses the coast. Once over land, Megan should weaken quickly below tropical cyclone strength. Copyright Commonwealth of Australia == The next bulletin for this system will be issued by: 18/0130 UTC.
Time (ACST) Intensity Category Latitude
(decimal deg.)Longitude
(decimal deg.)Estimated Position
Accuracy (km)0hr 4 am March 18 3 15.2S 137.2E 30 +6hr 10 am March 18 3 15.6S 137.1E 65 +12hr 4 pm March 18 3 15.8S 137.1E 90 +18hr 10 pm March 18 2 16.0S 136.9E 110 +24hr 4 am March 19 2 16.3S 136.6E 125 +36hr 4 pm March 19 tropical low 16.8S 135.8E 150 +48hr 4 am March 20 tropical low 16.9S 134.7E 180 +60hr 4 pm March 20 tropical low 16.7S 133.3E 215 +72hr 4 am March 21 tropical low 16.4S 131.6E 250
