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SIO: TROPICAL CYCLONE SEAN / TC 24S (JTWC)
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P.K.
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- Posts: 5149
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Re: SIO: TROPICAL LOW / TC 24S (JTWC)
13U remains a tropical low but is forecast at 45kts within 12 hours.
AXAU01 APRF 221812
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1812 UTC 22/04/2010
Name: Tropical Low
Identifier: 13U
Data At: 1800 UTC
Latitude: 13.2S
Longitude: 115.1E
Location Accuracy: within 30 nm [55 km]
Movement Towards: southwest [216 deg]
Speed of Movement: 5 knots [9 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1003 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:
Radius of Maximum Winds:
Dvorak Intensity Code: T2.5/2.5/d1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 23/0600: 14.1S 114.4E: 055 [100]: 045 [085]: 994
+24: 23/1800: 14.9S 113.3E: 085 [155]: 050 [095]: 990
+36: 24/0600: 15.7S 112.1E: 115 [215]: 055 [100]: 988
+48: 24/1800: 16.3S 110.8E: 150 [280]: 060 [110]: 985
+60: 25/0600: 16.9S 109.5E: 200 [370]: 050 [095]: 991
+72: 25/1800: 17.2S 108.1E: 245 [455]: 040 [075]: 998
REMARKS:
Deep convection has consolidated near the low level circulation centre. DT in
the 2.0 to 2.5 range. Development trend assessed as D therefore MET=2.5,
PAT=2.5, and hence FT/CI=2.5.
The low remains in an area of low vertical wind shear, very high ocean heat
content [SST>30C] and upper-level poleward outflow associated with a large
amplitude mid-latitude trough to the southwest; all features conducive for
further development. These environmental conditions are expected to continue in
the next 36 to 48 hours so development is forecast although the rate remains
somewhat uncertain and models do not favour rapid intensification. It is
possible that the circulation may be smaller than normal, supported by the
current extent of convection. This may result in greater fluctuations in
intensity than is typical.
During Saturday the shear should increase as the system moves southwestwards
towards the near stationary upper trough. By Sunday the system will be under
strong northwesterly shear and will be over lower SSTs and should be steadily
weakening. By Monday the system should be weak and beginning to be steered by
lower level winds out towards the west as deep convection is sheared away.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/0100 UTC by Perth TCWC.
AXAU01 APRF 221812
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1812 UTC 22/04/2010
Name: Tropical Low
Identifier: 13U
Data At: 1800 UTC
Latitude: 13.2S
Longitude: 115.1E
Location Accuracy: within 30 nm [55 km]
Movement Towards: southwest [216 deg]
Speed of Movement: 5 knots [9 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1003 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:
Radius of Maximum Winds:
Dvorak Intensity Code: T2.5/2.5/d1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 23/0600: 14.1S 114.4E: 055 [100]: 045 [085]: 994
+24: 23/1800: 14.9S 113.3E: 085 [155]: 050 [095]: 990
+36: 24/0600: 15.7S 112.1E: 115 [215]: 055 [100]: 988
+48: 24/1800: 16.3S 110.8E: 150 [280]: 060 [110]: 985
+60: 25/0600: 16.9S 109.5E: 200 [370]: 050 [095]: 991
+72: 25/1800: 17.2S 108.1E: 245 [455]: 040 [075]: 998
REMARKS:
Deep convection has consolidated near the low level circulation centre. DT in
the 2.0 to 2.5 range. Development trend assessed as D therefore MET=2.5,
PAT=2.5, and hence FT/CI=2.5.
The low remains in an area of low vertical wind shear, very high ocean heat
content [SST>30C] and upper-level poleward outflow associated with a large
amplitude mid-latitude trough to the southwest; all features conducive for
further development. These environmental conditions are expected to continue in
the next 36 to 48 hours so development is forecast although the rate remains
somewhat uncertain and models do not favour rapid intensification. It is
possible that the circulation may be smaller than normal, supported by the
current extent of convection. This may result in greater fluctuations in
intensity than is typical.
During Saturday the shear should increase as the system moves southwestwards
towards the near stationary upper trough. By Sunday the system will be under
strong northwesterly shear and will be over lower SSTs and should be steadily
weakening. By Monday the system should be weak and beginning to be steered by
lower level winds out towards the west as deep convection is sheared away.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/0100 UTC by Perth TCWC.
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HURAKAN
- Professional-Met
- Posts: 46086
- Age: 38
- Joined: Thu May 20, 2004 4:34 pm
- Location: Key West, FL
- Contact:
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0122 UTC 23/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 0000 UTC
Latitude: 13.6S
Longitude: 114.0E
Location Accuracy: within 25 nm [45 km]
Movement Towards: southwest [235 deg]
Speed of Movement: 7 knots [14 km/h]
Maximum 10-Minute Wind: 45 knots [85 km/h]
Maximum 3-Second Wind Gust: 65 knots [120 km/h]
Central Pressure: 995 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 km]
Radius of 34-knot winds NW quadrant: 50 nm [95 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:
Radius of Maximum Winds:
Dvorak Intensity Code: T3.0/3.0/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 23/1200: 14.5S 112.8E: 055 [100]: 050 [095]: 990
+24: 24/0000: 15.7S 111.7E: 085 [155]: 060 [110]: 985
+36: 24/1200: 16.5S 110.8E: 120 [220]: 060 [110]: 984
+48: 25/0000: 17.1S 109.9E: 150 [280]: 060 [110]: 984
+60: 25/1200: 17.3S 108.9E: 200 [365]: 045 [085]: 994
+72: 26/0000: 16.8S 106.6E: 245 [455]: 035 [065]: 998
REMARKS:
Tropical Cyclone Sean has developed overnight as deep convection consolidated
near the low level circulation centre. Dvorak analysis: DT=3.0 based on 0.75
curved band wrap [although 3.5 could also be possible with white band addition
factor]. MET/PAT also 3.0 with intensity rated at 45 knots [higher end T3.0].
This is also broadly consistent with SATCON estimates [45 knots one-minute].
Microwave imagery shows the LLCC north of the mid-level centre indicating that
the 10-15 knots of vertical wind shear is having an impact on the vertical
alignment. However, some further development is forecast through the next 36
hours supported by very high ocean heat content [SST>30C] and ongoing
upper-level poleward outflow associated with a large amplitude mid-latitude
trough to the southwest. As the shear is not expected to reduce it would seem
that rapid intensification is unlikely, although fluctuations in intensity is
possible because of the smaller than normal size of the circulation. Continued
southwest motion is expected to continue until weakening commences when lower
level steering winds should push it to the west.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/0700 UTC by Perth TCWC.
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0122 UTC 23/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 0000 UTC
Latitude: 13.6S
Longitude: 114.0E
Location Accuracy: within 25 nm [45 km]
Movement Towards: southwest [235 deg]
Speed of Movement: 7 knots [14 km/h]
Maximum 10-Minute Wind: 45 knots [85 km/h]
Maximum 3-Second Wind Gust: 65 knots [120 km/h]
Central Pressure: 995 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 km]
Radius of 34-knot winds NW quadrant: 50 nm [95 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:
Radius of Maximum Winds:
Dvorak Intensity Code: T3.0/3.0/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 23/1200: 14.5S 112.8E: 055 [100]: 050 [095]: 990
+24: 24/0000: 15.7S 111.7E: 085 [155]: 060 [110]: 985
+36: 24/1200: 16.5S 110.8E: 120 [220]: 060 [110]: 984
+48: 25/0000: 17.1S 109.9E: 150 [280]: 060 [110]: 984
+60: 25/1200: 17.3S 108.9E: 200 [365]: 045 [085]: 994
+72: 26/0000: 16.8S 106.6E: 245 [455]: 035 [065]: 998
REMARKS:
Tropical Cyclone Sean has developed overnight as deep convection consolidated
near the low level circulation centre. Dvorak analysis: DT=3.0 based on 0.75
curved band wrap [although 3.5 could also be possible with white band addition
factor]. MET/PAT also 3.0 with intensity rated at 45 knots [higher end T3.0].
This is also broadly consistent with SATCON estimates [45 knots one-minute].
Microwave imagery shows the LLCC north of the mid-level centre indicating that
the 10-15 knots of vertical wind shear is having an impact on the vertical
alignment. However, some further development is forecast through the next 36
hours supported by very high ocean heat content [SST>30C] and ongoing
upper-level poleward outflow associated with a large amplitude mid-latitude
trough to the southwest. As the shear is not expected to reduce it would seem
that rapid intensification is unlikely, although fluctuations in intensity is
possible because of the smaller than normal size of the circulation. Continued
southwest motion is expected to continue until weakening commences when lower
level steering winds should push it to the west.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/0700 UTC by Perth TCWC.
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HURAKAN
- Professional-Met
- Posts: 46086
- Age: 38
- Joined: Thu May 20, 2004 4:34 pm
- Location: Key West, FL
- Contact:
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0709 UTC 23/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 0600 UTC
Latitude: 14.0S
Longitude: 114.0E
Location Accuracy: within 25 nm [45 km]
Movement Towards: southwest [221 deg]
Speed of Movement: 5 knots [10 km/h]
Maximum 10-Minute Wind: 50 knots [95 km/h]
Maximum 3-Second Wind Gust: 70 knots [130 km/h]
Central Pressure: 990 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds:
Dvorak Intensity Code: T3.5/3.5/D1.5/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 23/1800: 14.9S 113.1E: 050 [095]: 055 [100]: 988
+24: 24/0600: 15.8S 112.3E: 080 [150]: 060 [110]: 984
+36: 24/1800: 16.5S 111.4E: 105 [195]: 060 [110]: 984
+48: 25/0600: 17.1S 110.6E: 140 [260]: 050 [095]: 991
+60: 25/1800: 17.4S 109.0E: 180 [335]: 040 [075]: 998
+72: 26/0600: 17.3S 106.2E: 220 [405]: 035 [065]: 1000
REMARKS:
Tropical Cyclone Sean has continued to develop as deep convection persists with
an improved banding feature evident especially on recent visible imagery.
Dvorak analysis: DT=3.5 based on 0.8 curved band. MET=3.0;PAT/FT/CI=3.5 with
intensity rated at 50 knots. This is slightly higher than current SATCON
estimates [45 knots one-minute].
Although the shear is only on the order of 10 knots there is some microwave
evidence suggesting some N-S tilting. Some further development is forecast
through the next 24-36 hours supported by very high ocean heat content [SST>30C]
and ongoing upper-level poleward outflow associated with a large amplitude
mid-latitude trough to the southwest. The system may become more vertically
aligned in the next 24 hours allowing greater intensification than forecast
especially during the overnight period.
Southwest motion is forecast in next 48 hours although some southerly motion is
also possible especially if the system deepens further. The lack of model
support for a more southerly track is probably due to the failure to resolve a
sufficiently deep/intense system. Once weakening commences, a shift to a more
westerly track is likely owing to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/1300 UTC by Perth TCWC.
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0709 UTC 23/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 0600 UTC
Latitude: 14.0S
Longitude: 114.0E
Location Accuracy: within 25 nm [45 km]
Movement Towards: southwest [221 deg]
Speed of Movement: 5 knots [10 km/h]
Maximum 10-Minute Wind: 50 knots [95 km/h]
Maximum 3-Second Wind Gust: 70 knots [130 km/h]
Central Pressure: 990 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds:
Dvorak Intensity Code: T3.5/3.5/D1.5/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 23/1800: 14.9S 113.1E: 050 [095]: 055 [100]: 988
+24: 24/0600: 15.8S 112.3E: 080 [150]: 060 [110]: 984
+36: 24/1800: 16.5S 111.4E: 105 [195]: 060 [110]: 984
+48: 25/0600: 17.1S 110.6E: 140 [260]: 050 [095]: 991
+60: 25/1800: 17.4S 109.0E: 180 [335]: 040 [075]: 998
+72: 26/0600: 17.3S 106.2E: 220 [405]: 035 [065]: 1000
REMARKS:
Tropical Cyclone Sean has continued to develop as deep convection persists with
an improved banding feature evident especially on recent visible imagery.
Dvorak analysis: DT=3.5 based on 0.8 curved band. MET=3.0;PAT/FT/CI=3.5 with
intensity rated at 50 knots. This is slightly higher than current SATCON
estimates [45 knots one-minute].
Although the shear is only on the order of 10 knots there is some microwave
evidence suggesting some N-S tilting. Some further development is forecast
through the next 24-36 hours supported by very high ocean heat content [SST>30C]
and ongoing upper-level poleward outflow associated with a large amplitude
mid-latitude trough to the southwest. The system may become more vertically
aligned in the next 24 hours allowing greater intensification than forecast
especially during the overnight period.
Southwest motion is forecast in next 48 hours although some southerly motion is
also possible especially if the system deepens further. The lack of model
support for a more southerly track is probably due to the failure to resolve a
sufficiently deep/intense system. Once weakening commences, a shift to a more
westerly track is likely owing to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/1300 UTC by Perth TCWC.
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HURAKAN
- Professional-Met
- Posts: 46086
- Age: 38
- Joined: Thu May 20, 2004 4:34 pm
- Location: Key West, FL
- Contact:
Re: SIO: TROPICAL CYCLONE SEAN / TC 24S (JTWC)
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm
----- Current Analysis -----
Date : 23 APR 2010 Time : 073000 UTC
Lat : 14:06:10 S Lon : 113:02:46 E
CI# /Pressure/ Vmax
3.8 / 982.3mb/ 61.0kt
Final T# Adj T# Raw T#
3.8 3.8 3.8
Latitude bias adjustment to MSLP : +3.1mb
Center Temp : -81.9C Cloud Region Temp : -81.8C
Scene Type : UNIFORM CDO CLOUD REGION
Positioning Method : FORECAST INTERPOLATION
Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC
Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm
----- Current Analysis -----
Date : 23 APR 2010 Time : 073000 UTC
Lat : 14:06:10 S Lon : 113:02:46 E
CI# /Pressure/ Vmax
3.8 / 982.3mb/ 61.0kt
Final T# Adj T# Raw T#
3.8 3.8 3.8
Latitude bias adjustment to MSLP : +3.1mb
Center Temp : -81.9C Cloud Region Temp : -81.8C
Scene Type : UNIFORM CDO CLOUD REGION
Positioning Method : FORECAST INTERPOLATION
Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC
Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF
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HURAKAN
- Professional-Met
- Posts: 46086
- Age: 38
- Joined: Thu May 20, 2004 4:34 pm
- Location: Key West, FL
- Contact:
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1256 UTC 23/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 1200 UTC
Latitude: 14.4S
Longitude: 113.7E
Location Accuracy: within 30 nm [55 km]
Movement Towards: south southwest [208 deg]
Speed of Movement: 5 knots [10 km/h]
Maximum 10-Minute Wind: 50 knots [95 km/h]
Maximum 3-Second Wind Gust: 70 knots [130 km/h]
Central Pressure: 990 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T3.5/3.5/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 24/0000: 15.4S 113.3E: 060 [110]: 060 [110]: 984
+24: 24/1200: 16.2S 112.7E: 090 [165]: 060 [110]: 984
+36: 25/0000: 16.8S 111.9E: 120 [220]: 055 [100]: 988
+48: 25/1200: 17.3S 110.6E: 155 [285]: 045 [085]: 995
+60: 26/0000: 17.4S 108.1E: 200 [370]: 035 [065]: 1002
+72: 26/1200: 17.3S 104.7E: 250 [465]: 030 [055]: 1005
REMARKS:
Deep convection persists near the LLCC of Tropical Cyclone Sean. Dvorak
analysis: DT between 3.0 and 3.5 based on 0.6 to 0.8 curved band on recent
visible and EIR imagery. MET=3.5 based on developing [D] trend; PAT/FT/CI=3.5
with intensity rated at 50 knots. This is slightly higher than current SATCON
estimates at 1100 UTC [49 knots one-minute average].
N'ly shear has increased slightly to between 15 and 20 knots based on CIMSS 12
UTC analysis and there is some microwave evidence suggesting some N-S tilting.
Some further development is forecast through the next 18-24 hours supported by
very high ocean heat content [SST>30C] and ongoing upper-level poleward outflow
associated with a large amplitude mid-latitude trough to the southwest. The
system may become more vertically aligned in the next 18-24 hours allowing
greater intensification than forecast especially during the overnight period.
Southwest motion is forecast in next 48 hours although some southerly motion is
also possible especially if the system deepens further. The lack of model
support for a more southerly track is probably due to the failure to resolve a
sufficiently deep/intense system. Once weakening commences, a shift to a more
westerly track is likely owing to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/1900 UTC by Perth TCWC.
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1256 UTC 23/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 1200 UTC
Latitude: 14.4S
Longitude: 113.7E
Location Accuracy: within 30 nm [55 km]
Movement Towards: south southwest [208 deg]
Speed of Movement: 5 knots [10 km/h]
Maximum 10-Minute Wind: 50 knots [95 km/h]
Maximum 3-Second Wind Gust: 70 knots [130 km/h]
Central Pressure: 990 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T3.5/3.5/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 24/0000: 15.4S 113.3E: 060 [110]: 060 [110]: 984
+24: 24/1200: 16.2S 112.7E: 090 [165]: 060 [110]: 984
+36: 25/0000: 16.8S 111.9E: 120 [220]: 055 [100]: 988
+48: 25/1200: 17.3S 110.6E: 155 [285]: 045 [085]: 995
+60: 26/0000: 17.4S 108.1E: 200 [370]: 035 [065]: 1002
+72: 26/1200: 17.3S 104.7E: 250 [465]: 030 [055]: 1005
REMARKS:
Deep convection persists near the LLCC of Tropical Cyclone Sean. Dvorak
analysis: DT between 3.0 and 3.5 based on 0.6 to 0.8 curved band on recent
visible and EIR imagery. MET=3.5 based on developing [D] trend; PAT/FT/CI=3.5
with intensity rated at 50 knots. This is slightly higher than current SATCON
estimates at 1100 UTC [49 knots one-minute average].
N'ly shear has increased slightly to between 15 and 20 knots based on CIMSS 12
UTC analysis and there is some microwave evidence suggesting some N-S tilting.
Some further development is forecast through the next 18-24 hours supported by
very high ocean heat content [SST>30C] and ongoing upper-level poleward outflow
associated with a large amplitude mid-latitude trough to the southwest. The
system may become more vertically aligned in the next 18-24 hours allowing
greater intensification than forecast especially during the overnight period.
Southwest motion is forecast in next 48 hours although some southerly motion is
also possible especially if the system deepens further. The lack of model
support for a more southerly track is probably due to the failure to resolve a
sufficiently deep/intense system. Once weakening commences, a shift to a more
westerly track is likely owing to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/1900 UTC by Perth TCWC.
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WTXS31 PGTW 230300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 24S (SEAN) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 24S (TWENTYFOUR) WARNING NR 002
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
230000Z --- NEAR 13.6S 113.8E
MOVEMENT PAST SIX HOURS - 245 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
REPEAT POSIT: 13.6S 113.8E
---
FORECASTS:
12 HRS, VALID AT:
231200Z --- 14.4S 112.6E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 235 DEG/ 06 KTS
---
24 HRS, VALID AT:
240000Z --- 15.1S 111.5E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 240 DEG/ 05 KTS
---
36 HRS, VALID AT:
241200Z --- 15.6S 110.5E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 250 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
250000Z --- 16.0S 109.2E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 260 DEG/ 06 KTS
---
72 HRS, VALID AT:
260000Z --- 16.3S 106.9E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 265 DEG/ 05 KTS
---
LONG RANGE OUTLOOK:
NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM
ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY
NEAR 20 KT EACH DAY.
---
96 HRS, VALID AT:
270000Z --- 16.4S 104.8E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
230300Z POSITION NEAR 13.8S 113.5E.
TROPICAL CYCLONE (TC) 24S (SEAN), LOCATED APPROXIMATELY 510 NM NORTH
OF LEARMONTH, AUSTRALIA, HAS TRACKED WEST-SOUTHWESTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS
INCREASED DEEP CONVECTION OVER THE LOW LEVEL CIRCULATION CENTER. A
222159 TRMM 85H AND A 222318 SSMIS 91H MICROWAVE IMAGES INDICATE
CONVECTIVE BANDING WRAPPING IN FROM THE SOUTH AND EAST OF THE SYSTEM
INTO A WELL-DEFINED LLCC. CURRENT INTENSITY IS BASED ON DVORAK
ESTIMATES OF 45 KNOTS FROM PGTW, APRF, AND KNES. UPPER LEVEL
ANALYSIS INDICATES THAT TC 24S IS TRACKING WEST-SOUTHWESTWARD ALONG
THE NORTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR). CURRENTLY
TC SEAN REMAINS IN A FAVORABLE ENVIRONMENT WITH ENHANCED POLEWARD
OUTFLOW AHEAD OF A MIDLATITUDE TROUGH AND LOW TO MODERATE VERTICAL
WIND SHEAR (VWS). NEAR TAU 36, TC 24S IS EXPECTED TO WEAKEN AS IT
ENCOUNTERS INCREASED VWS (20 TO 30 KTS). TC SEAN IS FORECAST TO
DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE BY TAU 96, WHICH IS A
CHANGE FROM THE PREVIOUS WARNING. NUMERICAL MODEL GUIDANCE IS IN
GOOD AGREEMENT WITH THIS FORECAST WITH THE EXCEPTION OF WBAR, WHICH
ERRONEOUSLY RECURVES THE SYSTEM TO THE SOUTHEAST. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 230000Z IS 14 FEET.
NEXT WARNINGS AT 231500Z AND 240300Z.//
NNNN
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TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1836 UTC 23/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 1800 UTC
Latitude: 14.9S
Longitude: 113.4E
Location Accuracy: within 30 nm [55 km]
Movement Towards: south southwest [213 deg]
Speed of Movement: 5 knots [10 km/h]
Maximum 10-Minute Wind: 55 knots [100 km/h]
Maximum 3-Second Wind Gust: 80 knots [150 km/h]
Central Pressure: 987 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T4.0/4.0/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 24/0600: 15.8S 113.0E: 060 [110]: 060 [110]: 984
+24: 24/1800: 16.5S 112.2E: 090 [165]: 060 [110]: 984
+36: 25/0600: 17.2S 111.2E: 120 [220]: 050 [095]: 991
+48: 25/1800: 17.4S 109.5E: 155 [285]: 040 [075]: 998
+60: 26/0600: 17.4S 106.3E: 200 [370]: 035 [065]: 1002
+72: 26/1800: 17.4S 102.8E: 250 [465]: 030 [055]: 1005
REMARKS:
Deep convection persists near the LLCC of Tropical Cyclone Sean. Dvorak
analysis: DT 4.0 based on MET.
System is still under N'ly shear expected to lie in the range of 15 and 20
knots. Some further development is forecast through the next 18-24 hours
supported by very high ocean heat content [SST>30C] and ongoing upper-level
poleward outflow associated with a large amplitude mid-latitude trough to the
southwest.
Southwest motion is forecast in next 48 hours although some southerly motion is
also possible especially if the system deepens further. The lack of model
support for a more southerly track is probably due to the failure to resolve a
sufficiently deep/intense system. Once weakening commences, a shift to a more
westerly track is likely owing to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 24/0100 UTC by Perth TCWC.
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1836 UTC 23/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 1800 UTC
Latitude: 14.9S
Longitude: 113.4E
Location Accuracy: within 30 nm [55 km]
Movement Towards: south southwest [213 deg]
Speed of Movement: 5 knots [10 km/h]
Maximum 10-Minute Wind: 55 knots [100 km/h]
Maximum 3-Second Wind Gust: 80 knots [150 km/h]
Central Pressure: 987 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T4.0/4.0/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 24/0600: 15.8S 113.0E: 060 [110]: 060 [110]: 984
+24: 24/1800: 16.5S 112.2E: 090 [165]: 060 [110]: 984
+36: 25/0600: 17.2S 111.2E: 120 [220]: 050 [095]: 991
+48: 25/1800: 17.4S 109.5E: 155 [285]: 040 [075]: 998
+60: 26/0600: 17.4S 106.3E: 200 [370]: 035 [065]: 1002
+72: 26/1800: 17.4S 102.8E: 250 [465]: 030 [055]: 1005
REMARKS:
Deep convection persists near the LLCC of Tropical Cyclone Sean. Dvorak
analysis: DT 4.0 based on MET.
System is still under N'ly shear expected to lie in the range of 15 and 20
knots. Some further development is forecast through the next 18-24 hours
supported by very high ocean heat content [SST>30C] and ongoing upper-level
poleward outflow associated with a large amplitude mid-latitude trough to the
southwest.
Southwest motion is forecast in next 48 hours although some southerly motion is
also possible especially if the system deepens further. The lack of model
support for a more southerly track is probably due to the failure to resolve a
sufficiently deep/intense system. Once weakening commences, a shift to a more
westerly track is likely owing to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 24/0100 UTC by Perth TCWC.
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TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0105 UTC 24/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 0000 UTC
Latitude: 15.5S
Longitude: 113.0E
Location Accuracy: within 25 nm [45 km]
Movement Towards: south southwest [212 deg]
Speed of Movement: 6 knots [12 km/h]
Maximum 10-Minute Wind: 55 knots [100 km/h]
Maximum 3-Second Wind Gust: 80 knots [150 km/h]
Central Pressure: 988 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T4.0/4.0/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 24/1200: 16.5S 112.5E: 060 [110]: 055 [100]: 988
+24: 25/0000: 17.3S 111.7E: 090 [165]: 060 [110]: 984
+36: 25/1200: 17.7S 110.4E: 120 [220]: 050 [095]: 991
+48: 26/0000: 17.8S 108.6E: 155 [285]: 040 [075]: 998
+60: 26/1200: 17.8S 105.6E: 200 [370]: 030 [055]: 1004
+72: 27/0000: 17.9S 102.2E: 250 [465]: 030 [055]: 1005
REMARKS:
Deep convection persists near the low level circulation centre of Tropical
Cyclone Sean. Dvorak analysis: Difficult to determine DT. MET of 4.0 based on
developing [D] trend. PAT= 4.0, FT/CI = 4.0.
1155 UTC SSMIS microwave image and 1812 UTC AMSRE image showed a tilting vortex
with the mid level centre displaced to the south.
Latest CIMSS shear analysis at 00 UTC indicates NW shear of about 15 knots. Some
further development is possible overnight if the shear remains low and with
ongoing upper-level poleward outflow associated with a large amplitude
mid-latitude trough to the southwest.
Southwest motion is forecast in the next 24 hours although some southerly motion
is also possible especially if the system deepens further. The lack of model
support for a more southerly track is probably due to the failure to resolve a
sufficiently deep/intense system. Once weakening commences, a shift to a more
westerly track is likely owing to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 24/0700 UTC by Perth TCWC.
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0105 UTC 24/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 0000 UTC
Latitude: 15.5S
Longitude: 113.0E
Location Accuracy: within 25 nm [45 km]
Movement Towards: south southwest [212 deg]
Speed of Movement: 6 knots [12 km/h]
Maximum 10-Minute Wind: 55 knots [100 km/h]
Maximum 3-Second Wind Gust: 80 knots [150 km/h]
Central Pressure: 988 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 80 nm [150 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T4.0/4.0/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 24/1200: 16.5S 112.5E: 060 [110]: 055 [100]: 988
+24: 25/0000: 17.3S 111.7E: 090 [165]: 060 [110]: 984
+36: 25/1200: 17.7S 110.4E: 120 [220]: 050 [095]: 991
+48: 26/0000: 17.8S 108.6E: 155 [285]: 040 [075]: 998
+60: 26/1200: 17.8S 105.6E: 200 [370]: 030 [055]: 1004
+72: 27/0000: 17.9S 102.2E: 250 [465]: 030 [055]: 1005
REMARKS:
Deep convection persists near the low level circulation centre of Tropical
Cyclone Sean. Dvorak analysis: Difficult to determine DT. MET of 4.0 based on
developing [D] trend. PAT= 4.0, FT/CI = 4.0.
1155 UTC SSMIS microwave image and 1812 UTC AMSRE image showed a tilting vortex
with the mid level centre displaced to the south.
Latest CIMSS shear analysis at 00 UTC indicates NW shear of about 15 knots. Some
further development is possible overnight if the shear remains low and with
ongoing upper-level poleward outflow associated with a large amplitude
mid-latitude trough to the southwest.
Southwest motion is forecast in the next 24 hours although some southerly motion
is also possible especially if the system deepens further. The lack of model
support for a more southerly track is probably due to the failure to resolve a
sufficiently deep/intense system. Once weakening commences, a shift to a more
westerly track is likely owing to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 24/0700 UTC by Perth TCWC.
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HURAKAN
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TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0701 UTC 24/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 0600 UTC
Latitude: 15.9S
Longitude: 112.6E
Location Accuracy: within 25 nm [45 km]
Movement Towards: southwest [218 deg]
Speed of Movement: 6 knots [11 km/h]
Maximum 10-Minute Wind: 55 knots [100 km/h]
Maximum 3-Second Wind Gust: 80 knots [150 km/h]
Central Pressure: 988 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 90 nm [165 km]
Radius of 34-knot winds SW quadrant: 90 nm [165 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T3.5/4.0/W0.5/06HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 24/1800: 16.8S 111.8E: 055 [100]: 055 [100]: 988
+24: 25/0600: 17.5S 110.8E: 085 [155]: 050 [095]: 990
+36: 25/1800: 17.6S 109.0E: 115 [215]: 040 [075]: 998
+48: 26/0600: 17.6S 105.9E: 150 [280]: 030 [055]: 1004
+60: 26/1800: 17.7S 102.6E: 200 [370]: 030 [055]: 1004
+72: 27/0600: 17.5S 99.7E: 245 [455]: 030 [055]: 1004
REMARKS:
In the last 6 hours Tropical Cyclone Sean has shown signs of weakening as NW
shear increases. Dvorak analysis: EIR shear pattern: <1/3 of a degree into
strong temperature gradient, DT = 3.5. Visible shear pattern: <1/3 of a degree
from edge, DT = 3.5. Met of 3.0 based on W- trend, PAT = 3.5. Therefore FT = 3.5
and CI held at 4.0.
Microwave imagery overnight showed a tilting vortex with the low level centre
located to the north of the mid level centre. The 2306 UTC SSMIS image showed
weakening in the deep convection to the north.
Latest CIMSS shear analysis at 06 UTC indicates NW shear of about 21 knots. It
now seams unlikely that the system will develop further overnight. Intensity may
be lower than forecast overnight if the shear increases further. A large
amplitude, slow moving, mid-latitude trough to the southwest is resulting in the
increasing NW shear.
Southwest motion is forecast in the next 18-24 hours before shifting to a more
westerly track after that due to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 24/1300 UTC by Perth TCWC.
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0701 UTC 24/04/2010
Name: Tropical Cyclone Sean
Identifier: 13U
Data At: 0600 UTC
Latitude: 15.9S
Longitude: 112.6E
Location Accuracy: within 25 nm [45 km]
Movement Towards: southwest [218 deg]
Speed of Movement: 6 knots [11 km/h]
Maximum 10-Minute Wind: 55 knots [100 km/h]
Maximum 3-Second Wind Gust: 80 knots [150 km/h]
Central Pressure: 988 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 90 nm [165 km]
Radius of 34-knot winds SW quadrant: 90 nm [165 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: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T3.5/4.0/W0.5/06HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 24/1800: 16.8S 111.8E: 055 [100]: 055 [100]: 988
+24: 25/0600: 17.5S 110.8E: 085 [155]: 050 [095]: 990
+36: 25/1800: 17.6S 109.0E: 115 [215]: 040 [075]: 998
+48: 26/0600: 17.6S 105.9E: 150 [280]: 030 [055]: 1004
+60: 26/1800: 17.7S 102.6E: 200 [370]: 030 [055]: 1004
+72: 27/0600: 17.5S 99.7E: 245 [455]: 030 [055]: 1004
REMARKS:
In the last 6 hours Tropical Cyclone Sean has shown signs of weakening as NW
shear increases. Dvorak analysis: EIR shear pattern: <1/3 of a degree into
strong temperature gradient, DT = 3.5. Visible shear pattern: <1/3 of a degree
from edge, DT = 3.5. Met of 3.0 based on W- trend, PAT = 3.5. Therefore FT = 3.5
and CI held at 4.0.
Microwave imagery overnight showed a tilting vortex with the low level centre
located to the north of the mid level centre. The 2306 UTC SSMIS image showed
weakening in the deep convection to the north.
Latest CIMSS shear analysis at 06 UTC indicates NW shear of about 21 knots. It
now seams unlikely that the system will develop further overnight. Intensity may
be lower than forecast overnight if the shear increases further. A large
amplitude, slow moving, mid-latitude trough to the southwest is resulting in the
increasing NW shear.
Southwest motion is forecast in the next 18-24 hours before shifting to a more
westerly track after that due to lower level steering winds.
Increasing northwesterly shear should result in weakening on Sunday and Monday
although gales may persist on the southern side of the circulation assisted by
westerly motion and a strengthening ridge to the south.
Copyright Commonwealth of Australia
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The next bulletin for this system will be issued by: 24/1300 UTC by Perth TCWC.
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