Saturday
A few showers in western areas in the morning, but many places will start dry, bright and quite cool. Sunny spells giving way to thickening cloud. Scattered showers passing east across central areas in the middle of day. Local heavy bursts for northern England & Scotland. Many eastern areas should stay dry. In the south-west, rain will turn persistent into the afternoon. A freshening southerly wind. Highs 13 to 17C, warmest south-east.

Saturday night
Rain fills in across much of the country into the evening and night, heaviest across south facing hills in the west. A humid air mass extends in from the Atlantic. Extensive low cloud and murk, particularly around south-western coasts and hills. Strong south to south-westerly winds, risk local gales in the north-west. Mild temperatures for many, 12 to 15C, but may dip to 7C in Scotland, or locally colder in the Highlands.

Sunday
Low pressure centred to the north-west of Britain pushes fronts across the country. Outbreaks of rain or drizzle, heaviest and most prolonged over the hills in the west & north-west. Extensive low cloud, and murky around western coasts. Some drier and brighter intervals in the south & east. Blustery south-westerly winds, up to gale force where exposed around coasts and hills. Feeling humid, highs 15 to 18C, perhaps a muggy 20C east.

Monday
A frontal system will advance east across the country, although much uncertainty about the location of the heaviest rain. It may skirt the south coast of England, but it may well extend widely across central Britain for several hours. A clearance should develop from the north-west, with some sunshine breaking through. Showery for Scotland & Northern Ireland, later also northern England. Windy, risk of gales. Feeling cool at 12 to 16C.