Tropical Cyclone Outlook for the Western Region

Issued at 2:00 pm WST on Thursday 2 February 2023
for the period until midnight WST Sunday 5 February 2023.

Existing Cyclones in the Western Region:

Nil.

Potential Cyclones:

A tropical low (11U) was around 11.6S 91.9E at 11am Thursday, around 540 km west of Cocos (Keeling) Islands is slowly moving. Recent model guidance has shifted, and it now is more likely for the system to stay within the region (east of 90E) for most of the week. 11U is likely to stay slow moving for the next few days, and then moving east or southeast on Sunday. If the system moves southeast there is a chance the system could develop, and there is a Low risk Monday/Tuesday, and Moderate risk Wednesday/Thursday. 11U is not expected to directly impact Cocos or Christmas Islands.

Likelihood of this system being a tropical cyclone in the Western Region on:

Friday:

Very Low

Saturday:

Very Low

Sunday:

Very Low

Over the next few days a tropical low 12U is likely to develop along the trough east southeast of Christmas Island, the environmental conditions are suitable for the low to deepen by late weekend and into Monday. The low is expected move west or southwest from Monday/Tuesday over open waters (away from the WA mainland). There is a Low risk of this system reaching TC intensity from Monday.

Some model guidance has another low, 13U, developing over open waters northwest of the Kimberley late weekend or early next week. Guidance indicates it as a small chance of forming, but if it does form and develop it is likely to track west or southwest over open waters well north of the Pilbara coast during Tuesday and Wednesday. The rating for this system, 13U, to develop into a tropical cyclone will increase to Low from Tuesday.

Likelihood of another system being a tropical cyclone in the Western Region on:

Friday:

Very Low

Saturday:

Very Low

Sunday:

Very Low

NOTES: The likelihood 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% to 20%

Moderate:

20 to 50%

High:

Over 50%

The Western Region refers to the Indian Ocean between Longitudes 90-125E and south of 10S.

Further information on Tropical Cyclones is available at www.bom.gov.au/weather/cyclone/