Storm forecast maps show exact date wall of rain hits and temps plummet by 14C

Britain is braced for a dramatic shift in weather at the end of August, with weather maps warning of heavy rain, strong winds and a sharp drop in temperatures. Weather map, generated by WXCharts on August 17 using Met Desk data, show a huge band of rain sweeping across Ireland and the UK on Wednesday, August 27 at 12pm, likely to bring heavy downpours.

The Met Office says high pressure, which has kept conditions settled and cool, will be pushed aside by powerful Atlantic systems linked to Hurricane Erin. Maps from WXCharts suggest the first signs of the storm will appear in 10 days, before a wall of rain crashes in from the west on Thursday morning.

Intense bursts, marked in red and yellow on the charts, are set to hit Ireland, Wales and western England before spreading eastwards through the day.

The deluge will coincide with a sharp temperature drop, with parts of the country expected to be 14C colder than recent highs. This summer, parts of the UK were battered by four heatwaves, with the mercury reaching 34C in July in London. Maps suggest that on August 26 England may still bake under 28C highs - only for temperatures to drop to the low 20s in the southern areas of Britain and low to mid 10s in Scotland.

A Met Office long-range outlook for August 22-31 said: "High pressure is likely to be the dominant feature at first bringing widely fine and dry weather whilst a generally northerly flow leads to rather cool conditions.

"This will be increasingly eroded from the west as frontal systems start to move in from the Atlantic through the weekend, leading to more changeable conditions. A deep area of low pressure is likely to develop in the North Atlantic, linked to Hurricane Erin, and may progress towards the UK."

While the exact track of the storm remains uncertain, forecasters say the north and west will bear the brunt of the worst conditions. There is also a small but growing risk of widespread wet and windy weather across much of the UK heading into the final days of August.

The warning comes just weeks after Britain endured a stop-start summer of unsettled spells, and raises fears of a washout for the final bank holiday of the season.