The forecast for the next 24 hours is a period of rain setting in from the south this afternoon, eventually reaching Cumbria this evening and continuing overnight before gradually withdrawing away to the North East tomorrow morning. The rain may not prove continuous throughout the event and may well only reach ‘steady’ intensities across a good part of the region. With the winds during this rainfall event coming from the E or NE the Pennines should hopefully ‘do their job’ and limit the likelihood of any disruption from the rainfall with most of the heavier rainfall falling over or to the east of the main high ground. The risk of any strong winds developing as the rain clears away tomorrow morning now looks extremely low.
Unfortunately that will not be the end of the story. Although we will enjoy a dry period from late Sunday morning through the afternoon the rain looks likely to return during the course of Sunday evening, more especially across Lancashire, Merseyside, Greater Manchester and Cheshire. This renewed rain could then last right through Sunday night and a good part of Monday, again ‘steady’ rain for the most part but with the odd heavier interlude quite possible before the rain fragments and finally clears away Monday evening.
Warnings/Flood Risk etc.
A Yellow Warning is now in force until midnight across the south of the region (Cheshire, south Merseyside and south/east Greater Manchester) to cover any minor impacts (surface water most likely) resulting from the portion of the rain that falls up to midnight. A second Yellow Warning covers all of Northwest England except Cumbria ,valid from midnight until 1000 tomorrow to cover tomorrow morning’s rain, whilst today’s Flood Guidance Statement (FGS, attached above) shows all of the region bar Cumbria on Yellow (low flood risk) for tomorrow for both surface water and river-related impacts. Although no severe weather warnings are currently in force across the region for Monday’s rain and the FGS is also green on Monday, the period of rainfall from tomorrow evening through Monday could still result in some minor impacts, chiefly from surface water excess, with Pennine areas most at risk.
From Tuesday onwards the threat from prolonged rainfall and risk of flooding should diminish steadily as the offending lows are finally given their marching orders and somewhat colder N to NE winds begin to assume dominance, bringing a few showers but also some sunshine.
An update briefing will be issued at around the same time tomorrow morning,
Alan Goodman; Met Office Advisor (Civil Contingencies)