The weather bureau says there is a high possibility of a cyclone forming in the Top End over the weekend.
Forecasters say a tropical low is developing off the north-west Australian coast.
The system is tracking first toward the Kimberley coast of Western Australia and is expected to reach the west coast of the Northern Territory in the next few days.
Forecaster Graeme King says it is unusual to see this type of weather system so early in the wet season.
"We have only ever had three cyclones before in November and normally our monsoon troughs, when most cyclones form are not expected ... until mid-December," he said.
Mr King says the WA Bureau of Meteorology may issue a weather watch for the Kimberley area over the next 24 hours.
© ABC 2013
00:28 EDT A boy has died and a girl has been taken to hospital with head, chest and leg injuries after a tree fell on their house during a severe thunderstorm in the Dandenong Ranges, east of Melbourne.