Topic: Tropical Cyclone Ilsa off WA : from 18 March 2009

[Colin Maitland]

Just observing the sat pics and noticed a low of North Western Australia.

Checking with BOM the report as quoted from them

SITUATION
At 1800 UTC a Tropical Low was centred within 30 nautical miles of
 latitude thirteen decimal two south (13.2S)
 longitude one hundred and fifteen decimal two east (115.2E)
Recent movement : west southwest at 16 knots
Maximum winds   : 30 knots
Central pressure: 1002 hPa
The low is expected to develop into a tropical cyclone within the next 18 hours.

AREA AFFECTED
Within 90 nautical miles of the centre.

FORECAST
Clockwise winds 20/30 knots increasing to 25/35 knots in southern quadrants by
0000 UTC 18 March with rough seas and moderate swell and then in remaining
quadrants by 1200 UTC 18 March.
Forecast positions
At 0600 UTC 18 March: Within 60 nautical miles of 13.9 south 112.4 east
                        Central pressure 1000 hPa.
                        Winds to 35 knots.
At 1800 UTC 18 March: Within 90 nautical miles of 14.7 south 110.0 east
                        Central pressure 996 hPa.
                        Winds to 40 knots.



At this stage it does not appear to be a threat due to the west south west movement.

Added track map from BOM showing her movements.

[Richary]

TROPICAL CYCLONE INFORMATION BULLETIN
Issued at 3:43 pm WDT on Wednesday 18 March 2009
BY THE BUREAU OF METEOROLOGY
TROPICAL CYCLONE WARNING CENTRE PERTH

Tropical Cyclone Ilsa (Category 2) was located at 3 pm WDT near 13.6S 111.9E,
that is 950 km north northwest of Karratha and 960 km north northwest of
Exmouth and moving west at 27 kilometres per hour.
Tropical Cyclone Ilsa is not expected to affect the Western Australian coast in
the next 48 hours.


Well off the coast, and doubt even Christmas or Cocos Islands will be in the firing line looking at the track forecast and cloud overlay on Google Earth.

[cloudfairy]

She is getting stronger, but fortunately far away from the coast. Will be interesting to see how she will interact with the low to her west.

[Colin Maitland]

On Thursday night, 19/03/09, cyclone Ilsa became a Cat4 system with a central pressure of 958 Hpa, she has since weakened on the 20/03/09, back to a Cat3 storm and is still moving away from the Western Australian coastline. Her main threat is to maritime vessels, due to the strong gale force winds and large swells.

Col