8 Mar 2013

Weekend snow update

Following my blog yesterday about winter biting back this weekend, I just wanted to give you a brief update on my thoughts for which places are most likely to see some snow this weekend and how much.

Before I get on to any detail, what I really want to emphasise to you is to not underestimate the potential disruption from snow and ice over the next few days. It may be March, but the weather can still provide wintry weather that would easily seem more at home in January and February.

The Met Office has already issued a number of warnings for snow and ice this weekend and these will no doubt be updated each day.

Saturday

During Saturday, there’ll be a band of cloud and rain across the central swathe of the UK.

As the day progresses, colder air will start to mix in and turn the rain to snow – initially over the hills and mountains of northern England, north Wales and the Midlands, but eventually down to low levels into the evening.

In the graphics below, you can see this change taking place between 3pm and 9pm, with the area of snow expanding over time as the colder air digs in.

The headache for us weather forecasters at the moment is how much snow will accumulate – especially given the recent warming of the ground during the mild weather we’ve had this week.

At the moment, hills and mountains above 200 metres look most likely to have accumulating snow where there could be 5-10cm. At low levels there could be a covering of a few centimetres during Saturday night but some places won’t see any settle.

What will be a widespread problem during Saturday night is ice – especially over the Pennines, where wet snow combined with a strong wind could ice power lines and cause problems for electricity supplies.

Sunday into Monday

Sunday daytime will see the band of sleet and snow from Saturday continue to push southwards across southern parts of England and Wales, tending to weaken as it does so.

Snow showers are likely across eastern parts of the UK, with a significant wind chill in a strong and gusty easterly wind.

The next headache during Sunday night and into Monday will be an area of low pressure moving northwards in the English Channel.

As the rain from this mixes with the cold air in place, there could be some snow (2-5cm) across the Channel Islands and southern parts of England and Wales – shown in the graphic below for 6am on Monday.

At this stage, snow is expected largely south of the M4 motorway, although there is a huge amount of uncertainty as to exactly how far north the band of snow will get and it is highly likely that the detail will change as we get closer to the time.

Nevertheless, the potential for some wintry weather is certainly there during the next few days and I recommend keeping an eye on the forecast on the Channel 4 Weather website. You can also follow my regular updates on Twitter – @liamdutton

Tweets by @liamdutton