Met office
UK Outlook for Tuesday 20 Mar 2018 to Thursday 29 Mar 2018:
After a few very cold days, temperatures will slowly start to recover through the start of this period. Tuesday and Wednesday will be largely cloudy but mostly dry aside from a few showers. Some spells of wet and windy weather are then expected to arrive from the west later in the week, with rain likely to be preceded by a spell of snow in the north. Inbetween spells of wet and windy weather, there will be some drier, brighter but colder interludes. Into the following week there is significant uncertainty in the forecast but a blocked or only slowly changing weather pattern seems most likely with the wettest weather likely to be in the south and the greatest chance of any snow in the north.
UK Outlook for Friday 30 Mar 2018 to Friday 13 Apr 2018:
There is significant uncertainty in the forecast throughout this period, but a blocked or slowly changing weather pattern is probable. There will most likely be a balance between Atlantic frontal systems affecting the south and west at times with colder air associated with high pressure out to the northeast. Mixed conditions are likely with wetter than average conditions expected across the south, while staying drier and perhaps colder to the north. Further snow is possible, especially in the north where it will also be windy at times. Temperatures will likely be below average with further night frosts, and any milder interludes will probably be only brief.
https://www.metoffice.gov.uk/public/weather/forecast