It’s very mild for November (some places across northern England didn’t fall below 16 Celsius last night !). The warmth of the air results from its tropical origins, but the downside of that is that it allows it to carry lots of moisture in the upper atmosphere. Given the right conditions, that can mean some very large rainfall totals. We had the right conditions in Cumbria and Pennine areas yesterday, and I’m afraid we’re looking at a very similar set-up for tonight and into the early part of Wednesday. A warm front will move very slowly southwards across the area. As the air is forced up over the hills by the brisk south westerly wind, it will cool, condense and drop a good deal of rain across the Cumbrian Fells and north Pennines. The ground is already well saturated, so surface water issues can be expected (exacerbated if any drainage systems find themselves blocked by fallen leaves). In addition we can expect a response from the river systems, and our colleagues in the EA will provide more information on this aspect.
The Yellow Warning of Rain is valid from 00:10 to 07:00 on Wednesday (medium likelihood, low impacts). It covers much of the Cumbrian Fells, western parts of County Durham and into the northwest of North Yorkshire. In excess of 60 mm of rainfall is likely on more exposed hill tops.
Once we get this batch of rain out of the way it will eventually become fine later on Wednesday night, giving a fine start to Thursday. More wind and rain will sweep in on Thursday afternoon/evening. Colder on Friday, with bright spells and scattered, blustery showers. The changeable weather will continue through the weekend.
As always, keep up to date on our website/app.
Kevin Wadsworth Met Office Advisor (Civil Contingencies)