UK Forecast: Cooler and showery - A spell of rain to come later, Aug 23 - 15:57

Friday Low pressure near to Norway, combined with high pressure to the southwest of Britain and Ireland, will maintain a relatively cool west to northwesterly airstream. Sunny intervals but a brisk and blustery west or northwesterly wind will bring showers, some heavy, to Western Scotland, Northern Ireland and Northwest England from the word go. Further to the south and east, a dry and largely sunny start but with showers breaking out during the course of the afternoon into the evening, with the breeze freshening too. Cool and breezy in the north, with strong winds for the west of Scotland, and fresher conditions starting to extend southeast. Factor in the wind and it will feel cool and fresh generally, daytime highs 13 to 15C in northern and western areas, 16 or 17C in the Midlands and around 19C in the southeast.

Friday Night Still some showers running into northern and western coastal areas on a fresh to strong west or northwesterly wind but becoming dry for most parts overnight with clear spells and the winds tending to ease. A cool, even chilly night, lows in the north 6 to 8C but down to around 3 in sheltered inland spots; nearer 7 to 10C in the south.

Saturday A transient ridge of high pressure, moving across from the west, will give most parts a quieter day but an occluding frontal trough will push east into Ireland overnight. Still the risk of one or two showers, chiefly in Western Scotland and Northwest England but for most parts a dry day with some sunshine. However, rain, some heavy, will move east across Ireland overnight to reach Western Scotland, West Wales and the southwest of England by or soon after dawn. Still quite a stiff northwesterly breeze in exposed coastal areas at first but the wind will ease gradually during the day. Winds strengthen from the south overnight in western areas, though, as the rain moves in. Highest temperatures 13 to 15C in the north and west, up to 20C in the east and south.

Sunday The occluding frontal trough over Ireland will move east across the British Isles during the day. Rain, still heavy at times, will spread gradually to the rest of Scotland, England and Wales, reaching the east and south of England towards and during the afternoon. Drier, brighter weather with some sunshine and just a scattering of showers will follow from the west, although the rain may linger into the evening across the south and east of England. Winds strengthen from around a southerly direction with the rain before swinging to the west as it clears. Highs 13 to 18C.

from Weather forecast weatheronline.co.uk http://www.weatheronline.co.uk/cgi-app/reports?LANG=en&MENU=202&DAY=20180823