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 UK has been enjoying a rather mild Autumn so far however it looks as though the UK is about to be plunged straight into winter.
As we go through the next couple of weeks the weather will be dominated by a large area of high pressure sat over the UK bringing fine days and frosty nights.
As we near the end of the month and into early November this high pressure looks set to move towards Scandinavia drawing in an bitterly cold Easterly air flow and of course a risk of heavy Snow once again.
At this stage there is still scope for change however its a weather pattern that could bring significant risks across the whole of the UK as it did earlier in the year. That spell of Easterly winds was responsible for the deaths of 17 people in the UK and 77 across Europe in total.
Despite the risks there is plenty of time for change and therefor there is alot of uncertainty. We will update you as/if the risks increase.
Remember the Beast from the East parts one and two last March?
For those who dont, There was bitterly cold temperatures with numerous heavy snowfalls effecting the majority of the UK.
Forecasters believe this came about due to what is know as ‘Sudden Stratospheric warming’
The term SSW refers to what we observe – rapid warming (up to about 50 °C in just a couple of days) in the stratosphere, between 10 km and 50 km up.
Ultimately this allowed high pressure to effect the flow of the UK’s weather. Rather than have mild Atlantic storms roll in high pressure blocked the flow from the west, And in turn gave way to periods of Easterly winds.
Since this occured the Atlantic has been very quiet with very little influence on the UK’s weather.
Infact the Summer that comes to an end today may well top the lot as the warmest on record. This once again down to the dominance of high pressure over or close to the UK.
(In summer a high pressure dominated pattern will generally result in warmer than average temperatures, The reverse is true in winter.)
The theory therefor is that should the pattern we have seen for the last 6 months or so persist the risk of a Beast from the East bringing a brutally cold winter and periods of heavy snowfall increase.
There are other factors in play which would add to the potential for a cold winter.
Currently we appear to heading towards a possible Solar maunder minimum, (an extended decades-long period of low solar activity) And a slow down of the Gulf stream due to a increase of fresh water in the North Atlantic.
Its all food for thought and one that could make Winter 2018/19 even more frosty than the last.
We will release a full winter forecast in October when we can look at further contributing factors.
We are now starting to see the 2nd coming thaw out and of course the main talking point amongst many on social media is about part 3.
So will we see a part 3 or is it just a few scaremongering pages/newspapers etc hyping for the sake of it?
Taking a closer look at the various model outputs it becomes apparent that the potential for colder incursions over the next two or three weeks is still there, However…
As we continue to progress through spring any such cold spell will have less impact.
For example an upper air profile of around -10c at the end of February would see temperatures struggle to get above freezing and with the sun not so high lying snow would last much longer.
By the end of March however the same upper air profile would result in temperatures reaching 4-7c and combined with a higher sun & warmer ground temperature any settling snow would be short lived.
Overall the output shows the potential for some snow falling, However disruptive snowfall is highly likely to be over with for this side of the year away from high ground and touch wood we can now start to look forward to warmer temperatures.
Heavy snowfalls are now almost certain as we go through the weekend & into the early part of next week.
However compared to the cold spell earlier in the month the longevity of the cold & size of area covered in snowfall will be reduced.
But dont let that make you think part 2 is a typical poor sequel that fails to live up to the original.
For those in the hardest hit areas conditions could be as bad if not worse in terms of snowfall.
Currently areas in the South East can expect to see snowfalls of 10-20cms with some places seeing more than 1 foot within a 48 hour spell of dangerous conditions which will include the risk of thundersnow through Sunday.
Other areas at risk include East Anglia, The Midlands, Central Southern England and the South West. Wales may see some showers giving slight accumulations.
We will release a map showing exactly what you need to be prepared for tomorrow afternoon so stay tuned.
So we have heard people questioning wether the beast is derserving of the name.
Well dont write it off just yet.
Today will see a big increase in shower activity all down the East coast with particular heavy falls in the South East, North East of England and East coast of Scotland.
These areas could see 30cms of snow fall over the period of the day with potentially more for the same areas by the end of the week.
The temperatures are also expected to drop a touch however the windchill will drop considerably as the winds pick up through today.
Even if you are not near the Eastern side of the country there is a good chance today will be the day you start to see some snowfall with anything between 2 and 10cms possible further West.
The end of the Week is still surrounded with some uncertainty. Yes we will see an area of Low pressure bump into the cold over the UK with a small chance of Blizzards, However the exact positioning and intensity of any precipitation is yet to be decided.
Forecasters are warning of a memorable spell of weather that could rival the conditions seen during the harsh winter of 1987!
Heavy snow showers are expected to pile in to Eastern areas on Monday before becoming heavier and widespread throughout the UK from Tuesday onwards.
The snow is just part of the potentially deadly conditions as strong winds will lead to massive drifts leaving some areas completely cut off.
Then there is the cold. Deep deep cold that will see the thermometer drop to around -12 and a real feel temperature down to -20c!
These conditions look set to remain across all parts until a massive winter storm approaches from the South for the end of the week.
This is still along way off and is far from certain however latest model outputs suggest a single snowstorm that could bring more than a foot of snow across many Southern areas including the city of London in addition to what will have already fallen!
The long term outlook does not point to spring conditions either with further cold and ocassionally snowy days ahead.