21 Mar 2013

Disruptive March snow as winter drags its heels

Winter has no intention of leaving us anytime soon, with more wintry weather expected across a large swathe of the UK during the next few days.

So far this month, temperatures have been well below average, with just one brief burst of spring-like warmth.

March is renowned for being a month than can deliver us a big range of weather. This time last year, we had summer-like warmth, with temperatures reaching the low 20s.

It was so warm, that Scotland broke its maximum temperature record for March, reaching 23.6C at Aboyne in Aberdeenshire.

But alas, this year, it’s not to be. Temperatures have struggled to reach double figures, let alone anywhere near 20C, with no signs of this happening soon.

As I mentioned in my blog a few days ago, the jet stream is much further south than normal, meaning that we are lying in a huge pool of cold that that is covering much of western Europe.

The problem during the next 48 hours will be milder air and rain trying to move in off the Atlantic, bumping into the colder air and producing significant snow.

During the past few days, there has been some uncertainty in where the worst of the snow will be, but the detail is now becoming clearer, with numerous weather warnings issued.

Friday

Overnight into Friday, persistent and, at times, heavy snow will start to fall over south west Scotland, Northern Ireland, the north Midlands, northern England (especially the Pennines westwards) and north east Wales.

The amount of accumulating snow is hard to pin down in March – especially when it falls during the daytime.

Nevertheless, it looks like as much as 20-40cm could fall across the higher hills and mountains above around 300 metres. At lower levels, there could be 5-10cm, with some places seeing as much as 15cm.

An added problem will be the strong to gale force south easterly wind. This will cause the snow to drift and give blizzards over higher routes, as well as ice.

For south west England and south Wales, it’ll be heavy rain rather than snow that could cause problems. With 40-60mm in places, there’s a risk of some localised flooding.

Saturday

Overnight into Saturday, the snow won’t only continue to fall in the same areas, but could also extend southwards across East Anglia, south east England and the rest of the Midlands.

Snow amounts further southwards will be difficult to get right – especially across south east England, where rain and sleet could be mixed in during the daytime.

However, it is possible that 2-5cm, locally 10cm, could fall – especially over the hills, but not exclusively so.

The band of snow is likely to weaken into Saturday evening, with ice then becoming a concern.

Potential impacts

The first thing I’d like to emphasise is to not underestimate how bad wintry weather can get in March. Snow over the next couple of days will easily rival weather that would be more typical of January and February.

Given the amount of snow that is expected to fall, there will no doubt be some travel delays, with road, rail and airline networks all likely to be affected. Higher routes will be particularly treacherous.

Also, given the combination of heavy snow and strong winds, icing may be a problem for power lines, with the possibility of power cuts.

Don’t forget, you can get the latest forecast for your area on the Channel 4 Weather website. I’ll also be tweeting regular updates through tomorrow on Twitter – @liamdutton

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