After a New Year holiday of strong winds and rain, forecasters say that there will be more of the same and a risk of thunder.
They expect the south-west wind of Force 6 or 7 to increase to strong or gale Force 8, with gusts to 50 mph by midday and locally severe gale Force 9, with gusts up to 60 mph during the afternoon.
The wind is expected to decrease fresh to strong by midnight but increase again later.
The weather has meant the cancellation of the Condor fast ferry to the UK. For more information: Click here
Islanders are being warned to take care particularly at high tide this evening at around 8 pm, with waves expected to crash over sea walls.
Duty forecaster Mark Le Cornu said that there were big tides at the moment and that people should be careful, especially along the south coast.
He said that the weather would continue to be mixed over the next few days, but that it was expected to stay mild with temperatures in double figures.