Severe winds of up to 70mph are expected to batter the region on Saturday.
Staff at Northern Ireland Electricity (NIE) remain on standby should the gusts cause any supply loss, while parts of the roof of a supermarket in Omagh were blown off.
Police cordoned off the area surrounding SuperValu on Market Street in the town.
A spokesman said parts of the roof were hanging over the street and the fire service was called in to make the area safe.
Press Association weather service MeteoGroup said winds would reach an average 45mph, but some areas would be hit with more severe gales.
“The east coast of Northern Ireland will be the worst hit with winds at sea as high as 70mph,” a forecaster said.
“Anybody who is travelling across to England or Scotland is likely to find the journey pretty unpleasant.”
Meanwhile, NIE said there had been minimal disruption to electricity services - with only a handful of its 840,000 customers affected.