Weather: Snow and ice warning across NI
The weather warning for Northern Ireland is in effect until 06:00 GMT on Friday.
Some disruption is likely due to forecast rain, sleet and snow.
Snow accumulation is expected to be mainly over higher ground, while at lower levels many places will see little, if any, snow.
Above 150 metres, including Glenshane Pass and the Antrim Hills, 5-10cm of snow is likely to fall with 15cm possible in a few places.
There is danger associated with icy conditions.
Police said Marble Arch Road in Enniskillen, County Fermanagh, had become impassable due to snow and ice.
The area of Shanice Hill Road at Kilwater, near Larne, is also impassable due to dangerous driving conditions as a result of snowfall and collisions in the area.
They urged people to drive more carefully.
Irish weather service Met Éireann has warned of snow and ice across much of the Republic of Ireland.
There is also a yellow rain warning in place in many counties.
“Possible power outage”
Snowfall is expected to subside later Thursday, and may be followed by rain and drizzle, especially in the southern and eastern regions.
As for the coast, the weather will likely be mostly rain and sleet, with snow spreading inland to the south during Thursday morning and northward in the afternoon.
Minor blizzard conditions could develop with brisk easterly winds as well.
According to the Met Office, there is a small chance of a power outage, which could affect services such as mobile phone coverage.
There is also a small possibility that some rural communities are isolated.
Roads could be affected, potentially causing travel delays and cancellations of some rail and air connections.
Northern Ireland experienced its first big freeze of the year last month, as a cold blast in the Arctic brought snow and ice.
In the Republic of Ireland, a snow and ice warning is in effect from 03:00 to 1:00 p.m. on Thursday for counties Clare, Tipperary, Galway, Laois, Offaly, Westmeath and Wicklow.
The counties of Cavan, Donegal, Monaghan, Leitrim, Mayo, Roscommon, Sligo and Longford are subject to the same warning between 05:00 and 20:00.
A yellow rain warning has been issued for Carlow, Dublin, Kildare, Louth, Meath, Wexford and Wicklow from 05:00 on Thursday until 05:00 on Friday.