Storm Callum is the third named storm this year and follows Storm Ali and Storm Bronagh that hit Britain last month.
The storm is expected to bring heavy rain between 6am on Friday and 6pm on Saturday, particularly over south-facing hills.
Gusts in excess of 110km/h were recorded, but no major incidents have yet been reported.
Western Power Distribution said more than 950 homes had been left without electricity in south-west England and almost 100 were without power in south Wales.
There is a chance of gusts of 70mph to 80mph in the Western Isles during Friday afternoon and evening.
Mr Hand said crews stand ready in all areas of the country and would be deployed when safe to do so.
A yellow weather warning for wind was issued on Friday morning over the West Midlands, including Shropshire, to remain in place until midnight. However, said Mr Nolan, "there remains the risk, depending on the very final track over the coming hours, that the far northwest of Mayo, Galway, West Kerry and Western Donegal could see winds in excess of 130km/h". The low centre may drift further west and the winds will not be as strong.
In the Republic, where Storm Callum was set to first make landfall, a national emergency co-ordination group met yesterday for a briefing on the dangers posed by the intense weather system.
Flights have been affected from Belfast International and Belfast City airports.
Services between Bray-Greystones and Howth-Howth Junction have resumed after earlier disruption.
Aer Lingus said in a statement on Twitter: "Aer Lingus: A number of flights on our European network have been cancelled on Friday 12 October due to #StormCallum".
"In all events, and if in any doubt, schools should err on the side of caution".
The Met Office has warned that homes and offices are likely to be flooded, with fast flowing or deep floodwater which could cause a danger to life.
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