Heavy rain brings flooding risk this weekend

Following Storm Abigail, which brought stormy weather to the far north and west of Scotland during Thursday night, the concern for this weekend turns to heavy rain and flooding.

The remnants of ex-Hurricane Kate will arrive on our shores this weekend, with an abundance of left over tropical moisture.

This tropical moisture will boost the amount of rainfall across north western parts of the UK, as it is forced up over the hills and mountains – effectively like squeezing water out of a sponge.

Medium risk of flooding

As the very moist air is forced upwards, it condenses, cools and forms rain clouds that will give heavy and persistent rain to north western parts of the UK for 36 hours or so.

At the moment, it looks like the greatest amount of rain will fall across north western parts of England and Wales, Northern Ireland and south west Scotland.

In these areas, 20-40mm of rain is widely expected, with as much as 60mm in places. For Cumbria, the Yorkshire Dales and mountains of north Wales, there could be as much as 150-200mm locally.

The Met Office has issued a number of yellow “be aware” and amber “be prepared” weather warnings, to highlight the risk of disruption.

Saturated ground

North western parts of the UK have had a tremendous amount of rain during the past week, to the point where the ground is at or near saturation.

This means that the ground has little or no capacity to soak up any more water, meaning that there is a low to medium risk of both surface water and river flooding.

As is always the case with river flooding, there is likely to be a delay between the time that the rain falls and the river levels rise.

Surface water flooding is likely to be more immediate – especially in places where the recent strong winds have blown leaves off trees into drainage systems which may have become blocked.

More rain next week

There are signs that the rain will eventually ease during Sunday, but looking further ahead, the weather is going to stay unsettled well into next week.

After a settled and warm autumn so far, the jet stream has increased in speed and taken a more southerly track in the past fortnight – catapulting areas of low pressure our way.

Autumn so far has seen a lack of any notable cold weather and this looks to be the case for the next week, with just a small signal of something colder for the final week of November.

Don’t forget, you can get the latest forecast on the Channel 4 Weather website. I’ll also be posting updates on Twitter – @liamdutton