But weather forecasters say it is not as bad as expected which is why they have dropped the warning from amber to yellow
There is the likelihood of widespread gales, with gusts 65-75 mph.
However, gusts of 80-90 mph are possible, the greatest risk being towards the northwest where there will also be frequent wintry showers.
The public should be aware of the potential for significant disruption to travel due to the very strong winds.
This is an update to the Alert issued on Sunday to extend the area further south.
On Monday night, Stena Line cancelled its 11.30 pm sailing on the Belfast-Cairnryan route because of the rough weather at sea.
Its first sailing today is not expected until 3.30 pm