A trough of low pressure extends across the southern half of the British Isles on Monday bringing a cold northerly airflow to northern portions of the country and a milder westerly airflow to southern areas. The southern half of the country and eastern coasts will have a cloudy start to the day though this should clear to give some good sunny spells through the afternoon. As westerly air streams across southern Ireland, Wales and the southwest of England it will bring some prolonged showers to these areas which will spread eastward through the day reaching the southeast by the early afternoon. Temperature highs of 4 to 6C for mainland Scotland; 7 to 8C for Ireland, north Wales and the north of England; 10 to 13C for south Wales and southern England.
Higher pressure builds from the west through Monday night and into Tuesday giving clear skies overnight for most. It will stay cloudy for the north west of Scotland, southern Ireland and southwestern parts of Wales and England. It will be dry too away from the northwest of Scotland where showers may be wintry for a spell. Overnight lows of -1 to 4C although it will be colder away from towns and cities. Widespread groundfrost is expected while ice could form on some roads, particularly in Scotland.
A ridge of high pressure remains over the British Isles for most of the day on Tuesday. Early morning groundfrost will be widespread over the northern half of the country. Cloud will build from the west through the afternoon reaching most areas by the early evening. Rain will follow behind reaching southwestern parts of Ireland late in the afternoon then Wales and southern England through the evening. High temperatures will reach 4 to 8C for most of the country though the southwest of England could see 10C.
High pressure is pushed back to the southeast through Wednesday morning as a low pressure system moves in from the Atlantic. A cloudy and wet start to the day for most of the country with the exception of the north of Scotland where it will remain dry. Rain will be slow to clear but Ireland, northern Wales and the northwest of England should see some brighter spells develop through the afternoon. Rain will turn to snow over mountaintops in the north of England. Feeling cold for mainland Scotland, Northern Ireland and the north of England with highs of 2 to 6C; highs of 9 to 12C for the rest of Ireland, Wales and England.