Winter Gritting Experts

Why UK Winter Weather Forecasting Rocks

October 27, 2018

We all know how variable and unpredictable the weather is in the UK but why is that?

What the UK and Japan have in common

Britain's unique weather is all down to the fact it is an island and where it's positioned on the planet, between the Atlantic Ocean and a large land mass, continental Europe. Britain is under an area where five main air masses meet. An air mass is a large body of air that has similar temperature and moisture properties throughout.
From the diagram you will see they are either polar or tropical and maritime or continental which influence the temperatures and moisture levels.


Of course you can also throw the jet stream into the mix which is a high-altitude ribbon of fast-moving air that is associated with weather systems in the UK. The position of the jet stream can make a huge difference to the type of weather we experience.

This mix for the UK is almost unique, the only other country that has similar influences is Japan, but in reverse in terms of where the land masses and seas are positioned.


Regional Variations 

The weather around the UK and its islands is variable due to the different air masses that meet over the different parts of the UK, bringing with them varying characteristics depending on the area.

Scotland and the northern isles are at the mercy of very cold Arctic winds; Ireland and the west of England have wet Atlantic weather; the south is influenced by winds from the Mediterranean whilst the east of the country has fierce north-sea winds to contend with.

Scotland and the north-east have traditionally been more affected by severe weather in winter than the rest of the UK but the South West and London has seen its share of extreme snowfall recently.

Even in winter some parts of the UK can bask in balmy temperatures while others struggle under heavy rain or snow.

According to a prediction over 20 years ago, recently concluded by scientific studies, global warming is set to provide the whole of the UK with milder winters long term, but with a variability year on year that will also bring extremely cold winters, such as the 2010-11 winter, where temperatures dropped to a mean of -0.7 degrees centigrade and last December when the temperature fell to -15C.


Snow from Latent Heat, Who Knew? 

If you’ve been fascinated by satellite images of weather fronts and maps with isobars and what the effects are on us mortals on the ground. No one loves a new weather term more than GRITIT here’s a great example of a forecast for Saturday afternoon (26 October).


Latent Heat Release Snow flurries

You should be able to make out a kink in the isobars across parts of the Northeast with some air which isn't quite as cold. This is a ‘short wave trough’ which runs in from the Northeast. Basically, it's where air coming in from upstream is moving quicker and then "piles up" against the air ahead of it which slows it down and forces it to rise. As it does this, it condenses and releases energy in the form of rain, hail etc. Don't worry though while we are out gritting already over the weekend, there's not enough snow to warrant any snow clearnance visits yet. 

This process is called latent heat release and it shows up as slightly warmer air in charts. If correct it should mean some transient snow cover across parts of the Cleveland Hills from this feature, which you can see from the grey patches on the snow map.  

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