Tropical Cyclone Outlook for the Western Region

Issued at 2:00 pm WST on Saturday 4 February 2023
for the period until midnight WST Tuesday 7 February 2023.

Existing Cyclones in the Western Region:

Nil.

Potential Cyclones:

A tropical low (11U) was located in the Indian Ocean near 12.5S 89.5E at 11am WST Saturday, about 800 km west of the Cocos (Keeling) Island. This low is expected to move east from tonight, towards Cocos Island. It is expected to come close to Cocos Island on Monday, before turning back towards the west southwest from late Monday onwards. There is increasing risk of the system developing into a tropical cyclone early next week. The system ratings are Low for Sunday 5th February, increasing to Moderate on Monday through till Thursday 9th of February. The overall risk of this low being a tropical cyclone in the Region begin to ease from Friday 10th February onwards as the system moves further southwestwards.

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

Sunday:

Low

Monday:

Moderate

Tuesday:

Moderate

A second weak tropical low (12U) was located well to the northwest of the WA coastline near 17.0S 107E at 11am WST Saturday, about 740km south of Christmas Island and 930km northwest of Exmouth. Conditions are unfavourable for this system to develop. It is expected to move westwards and weaken further over the coming days. The probability of 12U developing into a tropical cyclone is Very Low.

A third tropical low (13U) is forecast to develop over open waters, west of the Browse Basin on Sunday or Monday. This low is likely to track to the west-southwest over open waters, staying well north of the Pilbara coast through next week. Conditions are somewhat favourable for development, and the probability of this system developing into a tropical cyclone increases to Low on Monday the 6th of February, and to Moderate from Wednesday the 8th of February to Saturday the 11th of February. The system is not expected to pose any dircet threat to the WA coast or Christmas Island.

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

Sunday:

Very Low

Monday:

Low

Tuesday:

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/