SIO: VINCE (09U/06S) - Tropical Cyclone

[Crostorm]

At 9am Monday another low was located near 15S 112E and was nearly stationary.
This low is currently in an unfavourable environment but conditions for
development are likely to improve by Wednesday.

Likelihood of this system being a tropical cyclone in the Western Region:
Tuesday :Low
Wednesday :High
Thursday :High


NOTES: Development Potential is an estimate of the chance of each system being a
tropical cyclone in the Region for each day.
Very Low: less than 5% Low: 5% - 20%,
Moderate: 20% - 50% High: Over 50%

The Western Region refers to the Indian Ocean between Longitudes 90-125E and
south of Latitude 10S.
Further information on Tropical Cyclones is available at:
http://www.bom.gov.au/weather/cyclone/

[cycloneye]

10/1432 UTC 15.2S 110.2E T1.5/1.5 91S -- Southeast Indian

[HURAKAN]

Latest

[HURAKAN]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 15.0S 111.3E
IS NOW LOCATED NEAR 15.1S 111.1E APPROXIMATELY 440 NM NORTH-NORTHWEST
OF LEARMONTH, AUSTRALIA. ANIMATED INFRARED IMAGERY SHOWS A PARTIALLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION
DISPLACED TO THE WESTERN SEMI CIRCLE. THIS IS ALSO EVIDENT ON A
101126Z AMSU-B MICROWAVE IMAGE. THE CONVECTION IS BEING SHEARED
WESTWARD IN RESPONSE TO 30 KTS OF EASTERLY VERTICAL WIND SHEAR (VWS).
A 101348Z ASCAT PASS REVEALS A WELL-DEVELOPED LLCC WITH MAX 30-KT
WINDS IN THE NORTHERN PERIPHERY OF THE LLCC. THE SYSTEM LIES IN AN
ACTIVE MONSOON TROUGH ON THE EQUATORWARD SIDE OF THE SUBTROPICAL
RIDGE. A SHARP DECREASE IN VWS EXISTS BETWEEN 15 AND 17 DEGREES SOUTH
LATITUDE AND ANY SOUTHWARD MOVEMENT OF THE SYSTEM WOULD BRING IT INTO
SIGNIFICANTLY MORE FAVORABLE CONDITIONS. SEA SURFACE TEMPERATURES IN
THE REGION ARE 29-30 DEGREES CELSIUS. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 996 MB. DUE TO THE INCREASED LOW LEVEL WINDS AND
THE TWO NUMERIC MODELS FORECASTING A SOUTHERLY TRACK, THE POTENTIAL
FOR DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE DURING THE NEXT 24
HOURS IS UPGRADED TO FAIR.

[KWT]

Like the other system, the 18z GFS and the 12z ECM both are keen on developing this...

However the tracks are different, the 18z GFS takes quite a strong storm into NW Aus, whilst the 12z ECM keeps it a little offshore instead.

[HURAKAN]

At 9am Monday another low was located near 15S 112E and was nearly stationary.
This low is currently in an unfavourable environment but conditions for
development are likely to improve by Wednesday.

Likelihood of this system being a tropical cyclone in the Western Region:
Tuesday :Low
Wednesday :High
Thursday :High

[HURAKAN]

HIGH SEAS WEATHER WARNING FOR METAREA 10 ISSUED BY THE
AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE PERTH
AT 0406UTC 11 JANUARY 2011

GALE WARNING

Please be aware, wind gusts can be a further 40 percent stronger than the
averages given here, and maximum waves may be up to twice the height.

SITUATION
At 0000 UTC a Tropical Low was centred within 45 nautical miles of
latitude fourteen decimal nine south (14.9S)
longitude one hundred and eight decimal three east (108.3E)
Recent movement : west at 10 knots
Maximum winds : 25 knots reaching 30-40 knots in the northwest quadrant.
Central pressure: 996 hPa
The low is expected to develop into a tropical cyclone in the next 12 to 24
hours.

AREA AFFECTED
Within 60 nautical miles in northwest quadrant. Gales wrapping around the
centre by 0000 UTC 12 January with gales extending to 80 nautical miles in
southern quadrants and within 100 nautical miles in northern quadrants.

FORECAST
Maximum winds increasing to 40 knots in all quadrants by 0000 UTC 12 January.

Winds above 34 knots within 60 nautical miles of centre in the northwest
quadrant. Gales wrapping around the system centre by 0000 UTC 12 January with
gales extending to 80 nautical miles in southern quadrants and within 100
nautical miles in northern quadrants. Rough to very rough seas with moderate
swell.

Forecast positions
At 1200 UTC 11 January: Within 75 nautical miles of 14.8 south 107.4 east
Central pressure 992 hPa.
Winds to 30 knots reaching 40 knots in the northwest
quadrant.
At 0000 UTC 12 January: Within 100 nautical miles of 15.3 south 107.8 east
Central pressure 986 hPa.
Winds to 40 knots

REMARKS
All ships in the area please send weather reports every three hours.
Regular weather observing ships use normal channels.
Other ships please use either email to tcwcwa@bom.gov.au or fax to +61892632261
or satellite to SAC 1241 through Land Earth Station Perth 312.

Next warning will be issued by 0700 UTC 11 January 2011.

WEATHER PERTH

[HURAKAN]

At 8am WST Tuesday a low [09U] was located near 14.9S 108.3E and was moving west
at 19 kilometres per hour. This low is likely to develop into a tropical
cyclone on Wednesday, by which time it will be tracking eastwards towards the
Pilbara coast. It is not expected to affect the coast on Wednesday or Thursday.


Likelihood of this system being a tropical cyclone in the Western Region:
Wednesday :High
Thursday :High
Friday :High

[Crostorm]

IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0724 UTC 11/01/2011
Name: Tropical Low
Identifier: 09U
Data At: 0600 UTC
Latitude: 14.9S
Longitude: 107.7E
Location Accuracy: within 20 nm [35 km]
Movement Towards: west [270 deg]
Speed of Movement: 6 knots [11 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 994 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant: 80 nm [150 km]
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 STT:D0.5/6HRS
Pressure of outermost isobar: 998 hPa
Radius of outermost closed isobar: 90 nm [165 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 11/1800: 15.1S 107.6E: 055 [100]: 040 [075]: 986
+24: 12/0600: 15.5S 108.3E: 090 [165]: 045 [085]: 984
+36: 12/1800: 16.0S 109.7E: 110 [205]: 050 [095]: 982
+48: 13/0600: 16.6S 111.8E: 120 [220]: 060 [110]: 976
+60: 13/1800: 17.3S 113.8E: 150 [280]: 075 [140]: 963
+72: 14/0600: 18.0S 115.2E: 180 [335]: 085 [155]: 954
REMARKS:
The LLCC is clearly visible in VIS imagery, and the fix is based on this. The
LLCC has improved significantly and the CDO has shown some consolidation despite
ongoing shear of close to 30 knots indicated on the CIMSS analysis. The shear is
forecast to drop overnight due to a retrogressing upper trough, though models
differ on the relative location of the LLCC to the upper trough, leading to some
uncertainty as to how much the shear will drop. However in general conditions
should be much more favourable for development over the next 48 hours.

The Dvorak analysis is based on a shear pattern with less than 0.5 degrees
separation between the LLCC and the CDO. The improvement evident in the LLCC
allows an assignment of 2.5. Curved band patterns give a wrap of 0.35 yielding a
DT of 2. The improvement in the LLCC and consolidation of the CDO warrant a 24
hour trend of D and this gives a MET of 2.0. The PAT is 2.5 and as there is no
FT constraint on assigning 2.5 [6 hour old FT was 2.0, 24 hour old FT 1.0] this
is set as the FT and CI.

The ASCAT pass at 0235Z indicates a circulation of around 30 knots with gales in
the southwest quadrant, consistent with the Dvorak analysis.

Models all indicate the system will recurve to head east towards the coast
within the next 12 hours and will again recurve, this time to head westwards
around 12Z on 14 Jan [+/- 12 hours]. There is significant divergence between the
models on how fast the system will move while on the east southeastwards track
with some models bringing the system onto the coast while others imply no
coastal impact, with the system recurving well off the coast.

STIPS and model guidance generally do not show strong intensification during the
next 48 hours but an assessment of the synoptic conditions indicates favourable
conditions hence the system is forecast to intensify at roughly the
climatological rate.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 11/1300 UTC by Perth TCWC.

[RobWESTPACWX]

This GFS image looks pretty grim.

[Crostorm]

TPXS10 PGTW 110909

A. TROPICAL DISTURBANCE 91S (SOUTH OF JAVA)

B. 11/0832Z

C. 14.9S

D. 107.7E

E. FOUR/MTSAT

F. N/A

G. IR/EIR/VIS/MSI

H. REMARKS: 19A/PBO XPSD LLCC/ANMTN.

I. ADDITIONAL POSITIONS:
11/0701Z 14.9S 107.8E MMHS


BRANDON

[HURAKAN]

strong shear

[HURAKAN]

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1256 UTC 11/01/2011
Name: Tropical Low
Identifier: 09U
Data At: 1200 UTC
Latitude: 14.9S
Longitude: 107.5E
Location Accuracy: within 30 nm [55 km]
Movement Towards: west [270 deg]
Speed of Movement: 2 knots [4 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 994 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant: 80 nm [150 km]
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/D1.5/24HRS
Pressure of outermost isobar: 996 hPa
Radius of outermost closed isobar: 90 nm [165 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 12/0000: 15.1S 107.3E: 060 [110]: 040 [075]: 984
+24: 12/1200: 15.5S 108.2E: 090 [165]: 050 [095]: 979
+36: 13/0000: 15.7S 110.0E: 120 [225]: 055 [100]: 977
+48: 13/1200: 16.6S 112.2E: 155 [285]: 070 [130]: 966
+60: 14/0000: 17.5S 114.0E: 200 [375]: 080 [150]: 957
+72: 14/1200: 18.2S 114.8E: 250 [465]: 085 [155]: 948
REMARKS:
The LLCC was clearly visible on VIS imagery. Recent microwave imagery showed the
exposed LLCC and assisted in locating the centre. The LLCC has improved
significantly and the CDO has shown some consolidation despite ongoing shear of
close to 20 knots as indicated on the CIMSS analysis. The shear is forecast to
drop overnight due to a retrogressing upper trough, though models differ on the
relative location of the LLCC to the upper trough, leading to some uncertainty
as to how much the shear will drop. However, in general, conditions should be
much more favourable for development over the next 48 hours.

The Dvorak analysis is based on a shear pattern with less than 0.75 degrees
separation between the LLCC and the CDO giving a DT of 2.5. The improvement in
the LLCC and consolidation of the CDO warrant a 24 hour trend of D and this
gives a MET of 2.0. The PAT is 2.5 and so the FT and CI are set to 2.5.

The ASCAT pass at 0235Z indicates a circulation of around 30 knots with gales in
the southwest quadrant, consistent with the Dvorak analysis.

All models indicate the system will recurve towards the southeast within the
next 6 to 24 hours and will again recurve, this time to head westwards around
12Z on 14 Jan [+/- 12 hours]. There is significant divergence between the models
on how fast the system will move while on the east southeastwards track with
some models bringing the system onto the Pilbara coast while others imply no
coastal impact, with the system recurving well off the coast.

STIPS and model guidance generally do not show strong intensification during the
next 48 hours but an assessment of the synoptic conditions indicates favourable
conditions for development, hence the system is forecast to intensify at roughly
the climatological rate.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 11/1900 UTC by Perth TCWC.

[HURAKAN]

HIGH SEAS WEATHER WARNING FOR METAREA 10 ISSUED BY THE
AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE PERTH
AT 1243UTC 11 JANUARY 2011

STORM FORCE WIND WARNING

Please be aware, wind gusts can be a further 40 percent stronger than the
averages given here, and maximum waves may be up to twice the height.

SITUATION
At 1200 UTC a tropical low was centred within 30 nautical miles of
latitude fourteen decimal nine south (14.9S)
longitude one hundred and seven decimal five east (107.5E)
Recent movement : west at 2 knots
Maximum winds : 30 knots reaching 40 knots in the southwest quadrant.
Central pressure: 994 hPa
The low is expected to develop into a tropical cyclone in the next 6 to 12
hours.

AREA AFFECTED
Within 80 nautical miles of the centre.

FORECAST
Maximum winds to 40 knots in the southwest quadrant, increasing to 50 knots in
all quadrants by 1200 UTC 12 January.

Winds above 48 knots within 40 nautical miles of centre with very rough seas
and moderate to heavy swell by 1200 UTC 12 January.

Winds above 34 knots within 80 nautical miles of centre in the southwest
quadrant, extending to all quadrants by 1800 UTC 11 January with rough to very
rough seas and moderate swell.

Forecast positions
At 0000 UTC 12 January: Within 60 nautical miles of 15.1 south 107.3 east
Central pressure 984 hPa.
Winds to 40 knots near centre.
At 1200 UTC 12 January: Within 90 nautical miles of 15.5 south 108.2 east
Central pressure 979 hPa.
Winds to 50 knots near centre.

REMARKS
All ships in the area please send weather reports every three hours.
Regular weather observing ships use normal channels.
Other ships please use either email to tcwcwa@bom.gov.au or fax to +61892632261
or satellite to SAC 1241 through Land Earth Station Perth 312.

Next warning will be issued by 1900 UTC 11 January 2011.

WEATHER PERTH

[KWT]

The general idea from the models is for a bend back SE followed eventually by a curve out to the east. The key uncertainties is how close to land it gets before that bend back eastwards occur...

Either way both models are developing a fairly tight looking storm, so don't be surprised if this turns out to be quite a potent TC down the line.

[HURAKAN]

3rd system to try to develop in the same general area over the last few weeks only to find relentless shear

[HURAKAN]

WTXS22 PGTW 110800
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/110151JAN2011//
NAR/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN A
180 NM RADIUS OF 15.0S 107.8E WITHIN THE NEXT 12 TO 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL
CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO
BE 30 TO 35 KNOTS. METSAT IMAGERY AT 110532Z INDICATES A CIRCULATION
CENTER IS LOCATED NEAR 14.9S 107.8E. THE SYSTEM IS MOVING WEST-
NORTHWESTWARD AT 09 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 15.1S
111.1E IS NOW LOCATED NEAR 14.9S 107.8E, APPROXIMATELY 565NM
NORTHWEST OF LEARMONTH, AUSTRALIA. RECENT ANIMATED MULTISPECTRAL
IMAGERY SHOWS AN EXPOSED LOW LEVEL CIRCULATION WITH CONVECTION BEING
SHEARED 90NM TO THE WEST. AN 110235Z ASCAT PASS SHOWS A WELL DEFINED
35KT CLOSED CIRCULATION. AN 110607Z AMSU PASS SHOWS A WELL DEFINED
SURFACE CIRCULATION WITH CONVECTION STARTING TO FORM BANDING AROUND
THE WESTERN AND SOUTHERN SIDES, BUT STILL DISPLACED FROM THE CENTER.
THE CIRCULATION IS CURRENTLY BEING DRIVEN BY AN EQUATORIAL WESTERLY
WIND BURST, AND THE VERTICAL WIND SHEAR IS STILL TOO HIGH FOR THE
SYSTEM TO DEVELOP SUSTAINED CONVECTION TO FURTHER INTENSIFY. MODEL
GUIDANCE INDICATES A PASSING MIDLATITUDE TROUGH WILL WEAKEN THE
SUBTROPICAL RIDGE POLEWARD OF THE SYSTEM, ALLOWING IT TO MOVE TO THE
SOUTHEAST AND UNDER THE UPPER-LEVEL RIDGE AXIS. THIS WILL REDUCE THE
VERTICAL WIND SHEAR AND THE SYSTEM WILL LIKELY DEVELOP BETWEEN TAU
12 AND 24. THE POTENTIAL FOR DEVELOPMENT INTO A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
120800Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 18.9S 170.2E
//
NNNN

[HURAKAN]

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1838 UTC 11/01/2011
Name: Tropical Low
Identifier: 09U
Data At: 1800 UTC
Latitude: 14.9S
Longitude: 107.5E
Location Accuracy: within 30 nm [55 km]
Movement Towards: Stationary
Speed of Movement: 0 knots [0 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 990 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant: 80 nm [150 km]
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/S0.0/12HRS
Pressure of outermost isobar: 996 hPa
Radius of outermost closed isobar: 120 nm [220 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 12/0600: 15.3S 107.8E: 060 [110]: 045 [085]: 982
+24: 12/1800: 15.6S 109.3E: 090 [165]: 050 [095]: 980
+36: 13/0600: 16.2S 111.4E: 120 [225]: 060 [110]: 974
+48: 13/1800: 17.0S 113.3E: 155 [285]: 075 [140]: 961
+60: 14/0600: 17.8S 114.7E: 200 [375]: 085 [155]: 951
+72: 14/1800: 18.6S 115.0E: 250 [465]: 085 [155]: 948
REMARKS:
Shear continues to inhibit the system's development with microwave imagery
showing a well exposed LLCC. The shear is forecast to decrease due to a
retrogressing upper trough, though models differ on the relative location of the
LLCC to the upper trough, leading to some uncertainty as to how much the shear
will drop. However, in general, conditions should be much more favourable for
development over the next 48 hours.

The Dvorak analysis is based on a shear pattern with less than 0.75 degrees
separation between the LLCC and the CDO giving a DT of 2.5.

The system has slowed and all models indicate it will recurve towards the
southeast within the next 6 to 12 hours and will again recurve, this time to
head westwards around 12Z on 14 Jan [+/- 12 hours]. There is significant
divergence between the models on how fast the system will move while on the east
southeastwards track with some models bringing the system onto the Pilbara coast
while others imply no coastal impact, with the system recurving well off the
coast.

STIPS and model guidance generally do not show strong intensification during the
next 48 hours but an assessment of the synoptic conditions indicates favourable
conditions for development, hence the system is forecast to intensify at roughly
the climatological rate.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 12/0100 UTC by Perth TCWC.

[HURAKAN]

HIGH SEAS WEATHER WARNING FOR METAREA 10 ISSUED BY THE
AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE PERTH
AT 1841UTC 11 JANUARY 2011

STORM FORCE WIND WARNING

Please be aware, wind gusts can be a further 40 percent stronger than the
averages given here, and maximum waves may be up to twice the height.

SITUATION
At 1800 UTC a tropical low was centred within 30 nautical miles of
latitude fourteen decimal nine south (14.9S)
longitude one hundred and seven decimal five east (107.5E)
Recent movement : Stationary.
Maximum winds : 30 knots reaching 40 knots in the southwest quadrant.
Central pressure: 990 hPa
The low is expected to develop into a tropical cyclone in the next 6 to 12
hours.

AREA AFFECTED
Within 80 nautical miles of the centre.

FORECAST
Maximum winds to 40 knots in the southwest quadrant, increasing to 50 knots in
all quadrants by 1800 UTC 12 January.

Winds above 48 knots within 40 nautical miles of centre with very rough seas
and moderate to heavy swell by 1800 UTC 12 January.

Winds above 34 knots within 80 nautical miles of centre in the southwest
quadrant, extending to all quadrants by 0001 UTC 12 January with rough to very
rough seas and moderate swell.

Forecast positions
At 0600 UTC 12 January: Within 60 nautical miles of 15.3 south 107.8 east
Central pressure 982 hPa.
Winds to 45 knots near centre.
At 1800 UTC 12 January: Within 90 nautical miles of 15.6 south 109.3 east
Central pressure 980 hPa.
Winds to 50 knots near centre.

REMARKS
All ships in the area please send weather reports every three hours.
Regular weather observing ships use normal channels.
Other ships please use either email to tcwcwa@bom.gov.au or fax to +61892632261
or satellite to SAC 1241 through Land Earth Station Perth 312.

Next warning will be issued by 0100 UTC 12 January 2011.

WEATHER PERTH

[Grifforzer]

AXAU01 APRF 111838
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1838 UTC 11/01/2011
Name: Tropical Low
Identifier: 09U
Data At: 1800 UTC

Dvorak Intensity Code: T2.5/2.5/S0.0/12HRS
Pressure of outermost isobar: 996 hPa
Radius of outermost closed isobar: 120 nm [220 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 12/0600: 15.3S 107.8E: 060 [110]: 045 [085]: 982
+24: 12/1800: 15.6S 109.3E: 090 [165]: 050 [095]: 980
+36: 13/0600: 16.2S 111.4E: 120 [225]: 060 [110]: 974
+48: 13/1800: 17.0S 113.3E: 155 [285]: 075 [140]: 961
+60: 14/0600: 17.8S 114.7E: 200 [375]: 085 [155]: 951
+72: 14/1800: 18.6S 115.0E: 250 [465]: 085 [155]: 948
REMARKS:
Shear continues to inhibit the system's development with microwave imagery
showing a well exposed LLCC. The shear is forecast to decrease due to a
retrogressing upper trough, though models differ on the relative location of the
LLCC to the upper trough, leading to some uncertainty as to how much the shear
will drop. However, in general, conditions should be much more favourable for
development over the next 48 hours.
The Dvorak analysis is based on a shear pattern with less than 0.75 degrees
separation between the LLCC and the CDO giving a DT of 2.5.
The system has slowed and all models indicate it will recurve towards the
southeast within the next 6 to 12 hours and will again recurve, this time to
head westwards around 12Z on 14 Jan [+/- 12 hours]. There is significant
divergence between the models on how fast the system will move while on the east
southeastwards track with some models bringing the system onto the Pilbara coast
while others imply no coastal impact, with the system recurving well off the
coast.
STIPS and model guidance generally do not show strong intensification during the
next 48 hours but an assessment of the synoptic conditions indicates favourable
conditions for development, hence the system is forecast to intensify at roughly
the climatological rate.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 12/0100 UTC by Perth TCWC.