Cold air has been filtering across the UK over the past 12 hours and the risk of snow is on the rise.
During the next 48 hours there will be showers of rain, sleet, hail and snow which are expected to be heavy at times.
This coupled with a brisk wind will see the temperatures feel significantly colder than the true air temp.
But what about that threat of snow i hear you ask…
Current model predictions expect a wintry mix with a particular risk for snowfall above 200m. Despite this certain parts of the West Midlands and Wales could see snow down to low levels during the early hours of Wednesday morning making that morning commute a little tricky.
Elsewhere parts of Yorkshire, Scottish central belt and the Scottish Highlands could all see some snowfalling for a time throughout wednesday.
Beyond this the UK finds itself in a battle between low pressure trying to push in and High pressure situated to the North. The high pressure wants to push cold Arctic air southwards whilst powerful low pressure systems want to sweep mild air in off the Atlantic. Given the time range each model output has its own version of how this pans out but should it be high pressure we could be faced with another cold blast as we move into December.
The UK is now on the brink of the first major cold period that could be locked in right up until Christmas. Colder air will begin filtering across the UK from sunday evening and into next week.
Initially the risk is reserved to overnight frosts however from mid week onwards a threat of snow increases.
This first blast of cold weather is unlikely to deliver significant snowfall but it is the risk of a another exceptionally severe blast of Easterly winds as we head to the end of November and early December that could make this a notable event.
Its all being brought about by a change in the Arctic Ocsillation from a positive mode to a negative.
This will allow the blocking high to form resulting in a cold and relatively dry spell that could be difficult to break down.
Although dry conditions are favoured the UK is positioned precariously in this set up. Whilst much of Europe is dry the temperature differencial over the North Sea between the warmish waters and the bitterly cold easterly winds can lead to significant snow showers.
There is also the risk that occasional areas of low pressures will try to force the blocking high eastwards and where the two air masses collide the potential for significant frontal snowfall occurs.
At the moment details for such snowfalls cannot be forecast accurately at this time frame but the building blocks are already being put into place. With that in mind we will post an update and issue weather warnings as/if confidence on increases over the course of next week.
The UK looks set to see a return from an old friend that visited twice in March this year.
Model outputs are increasingly pointing to a bitterly cold Easterly.
The pattern will come about due to a change in the Arctic Oscillation. This change will see the AO turn negative. Opposed to a positive AO werby cold air tends to be bottled up at higher latitudes with a powerful jetstream going East to West we end up with a wavy jetstream which then allows cold air to plunge Southwards.
When the jetstream becomes buckled high pressure has a better chance of building at higher latitudes often referred to as Northern Blocking.
It is this scenario we are seeing from the weekend onwards. Initially cold air will not be to severe due to a lack of cold pooling to our East. However as time goes by this bitterly cold air will begin to make its march West through mainland Europe and eventually to UK shores.
Many model outputs are showing what this could potentially mean with forecasts of European snow cover to be the most widespread it has been in November since the bitter winter of 2010!
Currently there are varying degrees of severity being modelled due to the timeframe concerned however the risk is increasing for conditions similar to those experienced earlier on this year.
So what could we expect?
Well should the Beast return the weather will be bitterly cold with frequent overnight frosts, Biting windchill and snowfall possible just about anywhere.
Beyond this a continuation of a negative AO will see the potential for cold weather persisting well into December.
The new week is almost upon on us and with it a spell of significant and disruptive snow for some in the U.S with as much as 12″ falling.
Heavy snow will fall from around midday today for Denver and much of Colorado before spreading into Kansas, Texas and Oklahoma later on in the day.
The largest falls will spread from Denver down to Pueblo and South East to Amarillo with many areas hit by 3″ minimum and up to 12″ in the worst hit areas, Some of which will experience whiteout conditions.
Many of these areas will then see an exceptionally cold night with temperatures 20-30 degrees below the expected normal for November.
The band of snow will progress North East over the course of Monday and Tuesday bringing further significant accumulations for parts of New York State, Vermont and Maine before affecting Montreal and Quebec City in Canada.
Much of Europe has had one of the mildest Autumns for many years following on the theme from the hot summer.
And the positive news is that the latest model guidance suggests this pattern is set to continue for the next two to three weeks with a large area of high pressure over Europe pumping mild air from Northern Africa through Spain, France and the UK.
Of course at this time of year it wont quite be BBQ weather however it will certainly be a welcome spell for those looking to save on the heating bills.
Unfortunately this will not come as good news to all. Ski resorts across the Alps are reporting nearly no snowfall except at the highest resorts and with opening dates just a few weeks away many are keeping fingers crossed the current pattern will break sooner rather than later.
Much of the United States has had a mild time of it lately with temperatures 2-6 degrees above average in particular around the Lakes & the North East
Those balmy days will soon be forgotten as all that looks set to change with a freezing northerly which will bring a sharp decline in temperatures next week.
The ECMWF model anticipates temperatures to nose dive from around the 6TH of the month as the first major cold incursion takes place. This spell could last well beyond then as the cold air sweeps as far South as Tennessee.
At this range details of snowfall is to far off to predict however should such a significant cold spell take shape many areas will be at risk of large snowfalls with a particular risk of large lake effect falls.
We will bring an update with more details later in the week but for now its one to be aware of