Flood hit south Down now facing up to 'half a month's rainfall' on Wednesday, forecasters say

Winds of up to 70mph are forecast for coastal areas, and up to 40mm.

The yellow warning is effective from 2am until 10am.

Met Office meteorologist Simon Partridge said: “Over the Mournes and Antrim hills there is the possibility of seeing half a month’s rainfall,” overnight and on Wednesday morning.

"The average rainfall for November in Northern Ireland is 121mm… and there is potential to see up to 60mm of rain over some of the higher ground, so it will be a very wet and very windy start to the day.

"The good news is, that it does improve into the afternoon,” he said.

However, the forecaster added: "It will be quite mild, around ten or eleven degrees, but with the rain and the wind it’s not going to feel that warm if you’re out and about.​”

Some travel disruption was expected due to flooding on some roads, with spray reducing visibility.

Last month, torrential rain led to business premises in Newry and Downpatrick being forced to close due to flooding.

Mr Partridge said: “Due to the extent of the warnings that are being issued, it was deemed that a named storm would be a good idea because it will highlight to the public the risk associated, particularly as tomorrow (Wednesday) is likely to be quite a busy day on the roads with people travelling back home from Christmas and things like that.”