The Beast is Coming

In my last blog update, I talked about the potential for some very cold weather during February, potentially even a Beast from the East! ....and, it has followed through! Models during the last few days have really been consistent with the cold air and snow, and we now have 2 Amber Snow Warnings out already: One across Essex, Kent and East Anglia, and the other across Scotland. There is also a warning across the East Coast from Sunday through to Wednesday, with the chance for more updates and upgrades. 

It won't just be snow that's the issue, the cold will be too. The Met Office have issued a level 3/4 cold weather alert, with a 90% chance of severe cold. Look out for vulnerable friends and family, as they are particularly at risk from this kind of weather.

Some may be wondering where all this cold weather has come from? Well, it started off with a sudden warming of the stratosphere at the beginning of the year, combined with favourable thunderstorm development in the tropics, that lead to increased high pressure that has given way to this cold spell! The easterly winds will start being dragged in on the northern side of the low which will begin moving south through Saturday. You can see all the cold air currently across Scandinavia and now the North Sea just waiting to flood in on the current observations: 

However, the temperatures won't be as cold as the temperatures currently in parts of Northern Europe; this is because of something called airmass modification. That is because the cold air will flow over the relatively warm North Sea, and will then become more moist and unstable. It is this instability which will drive the very frequent snow showers expected later in the week.

You can get an idea of the snow showers from this model, the UKV. Bear in mind this model sometimes underdoes snow showers, and considering there are quite a lot of them alone, some areas could see quite a lot of snow where they organise. Something else that is interesting that I just touched on are 'streamers'. That's when the snow showers organise into bands of very heavy snow, and are particularly common in Estuaries. You can see hints of one across London and the Thames Estuary, as well as another near the Humber. Where these streamers occur, its entirely possible for places to see 10-20cm.In the past these streamers have sometimes produced more than 30cm! Combined with strong winds, most of the snow is expected to drift, which could cause some localised very deep areas of snow. Back in the BFTE 2018, I remember finding a snow drift of more than 1 metre. This strong wind will also give some very low windchill values, perhaps lower than -10c, so it makes it essential to wrap up warm. That is it from me today!

Alex