Thunderstorms could accompany snow showers in Derry on Friday, according to the Met Office.
The Met Office issued an updated weather warning for snow and ice in Derry and the rest of the North on Thursday morning.
The most recent warning is valid between 11:00am on Thursday and 11:55pm on Friday.
"Snow showers will be heaviest and most frequent across western Scotland where a further 10-20 cm is likely to build up above 200-300 m with 30 cm possible over the very highest routes," said the Met Office's Chief Forecaster.
"The high ground of Northern Ireland and northern England will also see 10-15 cm building up.
"At low levels, parts of the warning area will see three and seven centimetres of snow but some places near the west coast will see very little.
"Showers will be accompanied by hail and lightning at times, particularly across western Scotland. Here, in particular, there is potential for disruption to power supplies from lightning strikes. Winds will strengthen at times, particularly from later Thursday, bringing the potential for temporary blizzard conditions and drifting on hills and mountains."
Thunder and lightning accompanied snow storms over Derry on Tuesday.
According to the warning on the Met Office website travel delays are likely "as are public transport cancellations".
"In a few places, mainly upland areas, vehicles may become stranded," reads the warning.
"There is a chance of power cuts, while services such as mobile phone coverage may be affected. A few rural communities may become cut off. In addition some roads and pavements will turn icy, increasing the chances of accidents or injuries."