Britain’s dire weather will give way to spring warmth and sunshine after a -4C weekend of winter frosts and a dusting of snow. Pressure-pattern changes during the start of May will restore the ‘balance’, pushing temperatures back where they should be late spring. However, it will follow a late bite of cold with Polar winds this weekend to plunge Scotland and northern England back into winter. Southerly winds from the Atlantic will bring milder weather elsewhere, although bands of rain will dampen spring spirits. Met Office meteorologist Annie Shuttleworth said: “Low pressure will start to arri…