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AXAU01 ADRM 180717
IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 0717 UTC 18/03/2024
Name: Severe Tropical Cyclone Megan
Identifier: 09U
Data At: 0600 UTC
Latitude: 16.0S
Longitude: 136.9E
Location Accuracy: within 15nm (30 km)
Movement Towards: south southwest (200 deg)
Speed of Movement: 4 knots (8 km/h)
Maximum 10-Minute Wind: 75 knots (140 km/h)
Maximum 3-Second Wind Gust: 105 knots (195 km/h)
Central Pressure: 968 hPa
Radius of 34-knot winds NE quadrant: 95 nm (175 km)
Radius of 34-knot winds SE quadrant: 50 nm (95 km)
Radius of 34-knot winds SW quadrant: 40 nm (75 km)
Radius of 34-knot winds NW quadrant: 70 nm (130 km)
Radius of 48-knot winds NE quadrant: 45 nm (85 km)
Radius of 48-knot winds SE quadrant: 25 nm (45 km)
Radius of 48-knot winds SW quadrant: 20 nm (35 km)
Radius of 48-knot winds NW quadrant: 35 nm (65 km)
Radius of 64-knot winds: 30 nm (55 km)
Radius of Maximum Winds: 15 nm (25 km)
Dvorak Intensity Code: T4.5/4.5/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:  18/1200: 16.3S 136.7E:     030 (060):  060  (110):  977
+12:  18/1800: 16.6S 136.5E:     045 (080):  045  (085):  988
+18:  19/0000: 16.9S 136.2E:     055 (100):  035  (065):  994
+24:  19/0600: 17.0S 135.7E:     060 (115):  030  (055):  997
+36:  19/1800: 17.2S 134.3E:     070 (130):  030  (055):  997
+48:  20/0600: 17.0S 132.7E:     090 (165):  025  (045):  999
+60:  20/1800: 16.8S 131.0E:     105 (190):  025  (045): 1000
+72:  21/0600: 16.5S 129.4E:     125 (230):  020  (035): 1001
+96:  22/0600: 16.3S 126.6E:     165 (305):  020  (035): 1001
+120: 23/0600: 16.4S 124.8E:     200 (370):  020  (035): 1001
REMARKS:
Severe Tropical Cyclone Megan at category 3 (75 kn) intensity made landfall at
0600 UTC on the southwestern Gulf of Carpentaria coast. 

Position based on a combination of visible imagery, AMSR2 microwave at 05UTC,
and Centre Is observations with high confidence. An eye is yet to emerge on
IR/Vis imagery and the AMSR2 shows partial eye wall with deepest convection
northwest of the centre. This suggests that Centre Is likely experienced close
to the maximum winds in the NW eye wall:  peak 10 min. of 70 kn (131 km/h) and
gusts to 92 kn (170 km/h) with min pressure 976hPa generally consistent with
the estimated TC max wind of 75 kn and central pressure 968 hPa. This is
somewhat lower than the SAR at 2037UTC: 90 kn in northern quadrants and 70 kn
in southern quadrants. 

Dvorak analysis: DT=5.0 from embedded centre pattern in white; MET=4.5 based on
Steady 24h trend not adjusted. FT/CI=4.5. Objective aids are: SATCON 68 kn, ADT
63 kn, AiDT 69 kn, DPRINT 63 kn (all 1-min average) but now that it is overland
these will be the last values.  

Wind structure based upon many inputs: SAR, ASCAT, HSCAT, SMAP and SMOS, and
supported by observations.  

Motion will be slowly to the southwest overland. From Tuesday 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.  

Slow development has occurred despite the ongoing moderate to strong
northeasterly wind shear but otherwise favourable conditions; abundant low and
mid-level moisture, good poleward outflow and high SSTs (30-31C). Now over land
Megan should weaken quickly and be below tropical cyclone within 18-24h. Heavy
rainfall will accompany the low as it tracks over the Northern Territory in the
following days. At this stage reintensification over water is not expected in
the next 7 days.  

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 18/1330 UTC.

WTPS31 PGTW 180900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 19P (MEGAN) WARNING NR 012//
RMKS/
1. TROPICAL CYCLONE 19P (MEGAN) WARNING NR 012    
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   180600Z --- NEAR 16.0S 136.7E
     MOVEMENT PAST SIX HOURS - 225 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF 
     SATELLITE AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            030 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            080 NM NORTHWEST QUADRANT
   REPEAT POSIT: 16.0S 136.7E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   181800Z --- 16.6S 136.2E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT
                            020 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            030 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 230 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   190600Z --- 17.2S 135.5E
   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 36 HR POSIT: 250 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   191800Z --- 17.5S 134.6E
   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 48 HR POSIT: 270 DEG/ 06 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   200600Z --- 17.5S 133.3E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
180900Z POSITION NEAR 16.2S 136.6E.
18MAR24. TROPICAL CYCLONE 19P (MEGAN), LOCATED APPROXIMATELY 397
NM EAST-SOUTHEAST OF DARWIN, AUSTRALIA, HAS TRACKED SOUTHWESTWARD
AT 06 KNOTS OVER THE PAST SIX HOURS. TROPICAL CYCLONE (TC) 19P 
(MEGAN) MADE LANDFALL AT APPROXIMATELY 180500Z, ALONG THE SOUTHERN 
GULF OF CARPENTARIA, SOUTH OF CENTRE ISLAND. 19P IS EXPECTED TO 
TRACK SOUTHWESTWARD THROUGH TAU 24 THEN TURN WESTWARD THROUGH TAU 
48, DISSIPATING BY TAU 48 OVER NORTH-CENTRAL 
AUSTRALIA. 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 
977 MB.//
NNNN

全球热带气旋监测公报

AXAU01 ADRM 181246
IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 1245 UTC 18/03/2024
Name: Tropical Cyclone Megan
Identifier: 09U
Data At: 1200 UTC
Latitude: 16.2S
Longitude: 136.8E
Location Accuracy: within 20nm (35 km)
Movement Towards: southwest (216 deg)
Speed of Movement: 2 knots (5 km/h)
Maximum 10-Minute Wind: 55 knots (100 km/h)
Maximum 3-Second Wind Gust: 75 knots (140 km/h)
Central Pressure: 981 hPa
Radius of 34-knot winds NE quadrant: 60 nm (110 km)
Radius of 34-knot winds SE quadrant: 50 nm (95 km)
Radius of 34-knot winds SW quadrant: 30 nm (55 km)
Radius of 34-knot winds NW quadrant: 50 nm (95 km)
Radius of 48-knot winds NE quadrant: 20 nm (35 km)
Radius of 48-knot winds SE quadrant: 15 nm (30 km)
Radius of 48-knot winds SW quadrant: 15 nm (30 km)
Radius of 48-knot winds NW quadrant: 20 nm (35 km)
Radius of 64-knot winds:  nm ( km)
Radius of Maximum Winds: 15 nm (30 km)
Dvorak Intensity Code: n/a
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:  18/1800: 16.5S 136.6E:     035 (065):  045  (085):  988
+12:  19/0000: 16.9S 136.3E:     045 (085):  035  (065):  994
+18:  19/0600: 17.2S 136.0E:     055 (100):  030  (055):  996
+24:  19/1200: 17.4S 135.5E:     060 (110):  030  (055):  994
+36:  20/0000: 17.5S 134.2E:     070 (130):  030  (050):  996
+48:  20/1200: 17.3S 132.8E:     085 (155):  025  (045):  998
+60:  21/0000: 17.1S 131.0E:     105 (190):  025  (045):  999
+72:  21/1200: 16.8S 129.8E:     125 (230):  020  (035):  999
+96:  22/1200: 16.6S 127.6E:     170 (310):  020  (035):  999
+120: 23/1200: 16.6S 126.1E:     200 (370):  020  (035):  998
REMARKS:
Severe Tropical Cyclone Megan at category 3 (75 kn) intensity made landfall at
0600 UTC on the southwestern Gulf of Carpentaria coast. 

Currently, the weakening system lies some 30km inland, and the low level centre
position is becoming more uncertain as the cloud signature loses coherence. The
persistence of deep layer northeasterly shear is inferred from the sharper IR
temperature gradient in that quadrant. Position is based on proximal surface
observations, peripheral radar data, and extrapolation. 

Dvorak analysis is now not applicable with the centre over land, with most
objective guidance similar. Intensity is analysed at 55 knots based on an
inland decay model adjusted to accommodate surrounding observations, combined
with numerical model guidance. Wind structure is now also largely based on
surrounding observations and model guidance. 

Slow southwest motion is expected to continue in the short term, and Megan
should weaken below tropical cyclone intensity during the next 12 hours. From
Tuesday, a mid-level ridge to the south is expected to strengthen and steer the
system west across the Northern Territory. Heavy rainfall will accompany the
low as it tracks over northern Australia in the following days. 

The low may approach the Kimberley coast late in the week, but
reintensification over water is not expected in the next 7 days.  

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 18/1930 UTC.

AXAU01 ADRM 181845
IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 1845 UTC 18/03/2024
Name: Tropical Cyclone Megan
Identifier: 09U
Data At: 1800 UTC
Latitude: 16.5S
Longitude: 136.6E
Location Accuracy: within 25nm (45 km)
Movement Towards: south southwest (213 deg)
Speed of Movement: 4 knots (7 km/h)
Maximum 10-Minute Wind: 40 knots (75 km/h)
Maximum 3-Second Wind Gust: 55 knots (100 km/h)
Central Pressure: 989 hPa
Radius of 34-knot winds NE quadrant: 50 nm (95 km)
Radius of 34-knot winds SE quadrant: 25 nm (45 km)
Radius of 34-knot winds SW quadrant: 25 nm (45 km)
Radius of 34-knot winds NW quadrant: 40 nm (75 km)
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: 25 nm (45 km)
Dvorak Intensity Code: 
Pressure of outermost isobar: 1002 hPa
Radius of outermost closed isobar: 180 nm (335 km)
FORECAST DATA
Date/Time    : Location    : Loc. Accuracy: Max Wind   : Central Pressure
(UTC)        : degrees     :      nm  (km): knots(km/h): hPa
+06:  19/0000: 16.9S 136.3E:     040 (070):  030  (055):  992
+12:  19/0600: 17.2S 136.0E:     050 (090):  030  (055):  993
+18:  19/1200: 17.4S 135.5E:     055 (100):  030  (055):  994
+24:  19/1800: 17.4S 134.9E:     060 (110):  030  (055):  995
+36:  20/0600: 17.3S 133.6E:     075 (140):  025  (045):  997
+48:  20/1800: 17.2S 132.0E:     090 (170):  025  (045):  998
+60:  21/0600: 17.0S 130.4E:     120 (225):  020  (035): 1000
+72:  21/1800: 16.7S 129.2E:     145 (270):  020  (035):  999
+96:  22/1800: 16.6S 127.1E:     185 (340):  020  (035):  999
+120: 23/1800: 16.6S 125.8E:     200 (370):  020  (035):  998
REMARKS:
Severe Tropical Cyclone Megan at category 3 (75 kn) intensity made landfall at
0600 UTC on the southwestern Gulf of Carpentaria coast. 

Megan continues to weaken as it tracks inland of the Gulf of Carpentaria coast,
though the low level centre position is becoming more uncertain as the cloud
signature loses coherence. Position is based on proximal surface observations,
peripheral radar data, and extrapolation. 

Dvorak analysis is now not applicable with the centre over land, with most
objective guidance similar. Intensity is now estimated to be at around 40 knots
based on an inland decay model. All surrounding observation sites are no longer
showing gale force winds as the system tracks further inland. 

The system is expected to be downgraded to a tropical low during this morning
before it tracks west through the Northern Territory over the next few days
under the influence of a mid-level ridge to the south. Heavy rainfall will
accompany the low as it tracks over northern Australia in the following days. 

The low may approach the Kimberley coast late in the week, but
reintensification over water is not expected in the next 7 days.  

Copyright Commonwealth of Australia
==
There will be no further bulletins for this system unless it reintensifies.

IDD20150

Australian Bureau of Meteorology
Tropical Cyclone Warning Centre

Media: The Standard Emergency Warning Signal should NOT be used with this warning.

PRIORITY
TROPICAL CYCLONE ADVICE NUMBER 34
Issued at 7:23 am ACST on Tuesday 19 March 2024

Headline:
Megan now downgraded to a tropical low as it tracks inland of the Gulf of Carpentaria coast

Areas Affected:
Warning Zone
None.

Watch Zone
None.

Cancelled Zone
Bing Bong to the NT/Qld Border, extending inland to Borroloola, McArthur River Mine, and Robinson River.

Details of Ex-Tropical Cyclone Megan at 6:30 am ACST:
Intensity: Ex-Tropical Cyclone Megan, sustained winds near the centre of 55 kilometres per hour with wind gusts to 85 kilometres per hour.

Location: within 45 kilometres of 16.7 degrees South 136.5 degrees East, estimated to be 75 kilometres south southeast of Borroloola and 55 kilometres west northwest of Robinson River.

Movement: south southwest at 9 kilometres per hour.

Megan has now been downgraded to a tropical low inland of the Gulf of Carpentaria coast, south of Borroloola. Ex-tropical cyclone Megan is forecast to track towards the west through inland parts of the Northern Territory over the next few days.

Severe Tropical Cyclone Megan made landfall at category 3 intensity on the southwestern Gulf of Carpentaria coast, southeast of Port McArthur, at 3:30 pm ACST. The highest wind gusts recorded were from Centre Island with wind gusts to 170 km/h (3:00 pm ACST) and Borroloola with wind gusts to 81 km/h (4:06 pm ACST).

Hazards:
HEAVY to locally INTENSE RAINFALL and DAMAGING WINDS will continue in the Carpentaria forecast district, while extending into the northern Barkly during today. A Severe Weather Warning is current and a Flood Watch continues for inland parts of the NT and Carpentaria Coastal Rivers.

Tides will be continue to be HIGHER THAN NORMAL along the southern Gulf of Carpentaria coast over the next few days. Large waves may produce MINOR FLOODING of low-lying coastal areas.

Recommended Action:
The Northern Territory Emergency Service advise:

For the communities in the area:

- Stay informed - threat is reduced

- Monitor conditions

- Do not enter flood waters

- Keep clear of power lines

- Be careful of fallen trees, damaged buildings and debris

- Take extra care on the roads

- Drive slowly and be aware of emergency service personal

- Be aware of potentially contaminated water supplies

Next Advice:
No further advices will be issued for this system.

This advice is available on telephone at 1300 659 210

A map showing the track of the cyclone is available at: http://www.bom.gov.au/cyclone

全球热带气旋监测公报