Yorkshire will be among the regions likely to be hit by heavy rains, with an additional risk of snow.
The brief cold snap tomorrow and Wednesday will be accompanied by strong northerly winds, said Julian Mayes, senior forecaster with MeteoGroup.
"It's turning very unsettled and we expect a two-day cold snap on Tuesday and Wednesday, which is going to give quite a surprise to many people after the recent mild weather. But even if people miss the snow, it's going to be cold and windy and wet.
"It should be milder by Friday, with rain coming in from the south west, but unfortunately it does look an unsettled picture over the Easter weekend."
The country has seen mild temperatures for the best part of 10 days but that is all set to change tomorrow as the severe weather moves in.
Met Office forecasters say the heavy and prolonged rain could give totals of more than 25mm, with the possibility of more than 10cm of snow on high ground and the risk of drifting in strong winds. Moderate accumulations of snow are also possible elsewhere as temperatures plunge back towards freezing.
The unsettled weather is likely to continue into the weekend but conditions should improve from Sunday and into next week, according to Met Office forecasts.
Mr Mayes said: "The month started cold, but the warmer temperatures recently have taken the whole month up to about average for March."