The warnings keep on coming as the first significant wintry spell sets it sights on the UK.
Before we get into the detail its worth baring in mind that whilst there is a severe spell of weather expected the duration is expected to be quite short with the main timeframe for severe conditions from Saturday afternoon through till 06:00 Sunday with a return to average temperatures on Monday.
As you can there is alot to contend with over the 18 hour period from midday on Saturday. Even before this period begins areas outside of the areas shaded red may well see some wet snow falling for a short period of time however accumulations are unlikely.
As the bulk of the precipitation bumps into the cold air anywhere from the North Midlands Northwards need to be prepared for snow or freezing rain. Initially snow is expected but as the weather fronts move across the UK it is likely a warm layer will melt the snow as it falls however temperatures at ground level may still be at or below freezing turning this super cooled rain immediately to ice upon impact.
This phenomenon is quite rare in the UK however it can be lethal for those who are braving the elements. Black ice will form readily and trees and powerlines can be brought down under the weight of the ice. The latter may not take place due to the relatively short period of time freezing rain is expected, However slippery surfaces are almost assured so it may be worth getting out and about early if you are still looking for those Christmas presents.
Another hazard will be for any of the high travel routes, The heavy snow in these areas will be accompanied by strong winds gusting up to 60MPH with a risk of Blizzard conditions so expect some road closures.
As for those outside of the areas shaded in red Saturday will be a blustery and wet day from around 3pm onwards before the rain clears away during the evening. This will then be followed up by a much calmer, drier day Sunday.
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.
NOAA’s Climate prediction centre announce a 75% chance of an El Nino winter this year and whilst it is not expected to be the strongest ever seen it will still effect the weather we see.
In summary El Niño is the warm phase of the El Niño Southern Oscillation (ENSO), stretching along the equator across the Pacific Ocean. It is known to trigger intense weather patterns across the world.
Typically El nino winters will lead to colder weather towards the Gulf states of the U.S whilst being milder than usual in the North West of the country. Higher than usual precipitation can tend to give way to potentially record breaking snowfalls later in the season.
For the UK and the North West of Europe El Nino winters tend to be colder than average which will of course increase the likelihood of snowfall events. Whilst individual snowfall events look likely this winter they will almost certainly be interspersed between milder spells due to the temperate climate of the UK. So those hoping them headlines of ‘4 months of crippling snow’ would be true are likely to be dissapointed.
Other factors to consider for the UK also point to a colder winter:
At present the current solar cycle is the 24th. Solar cycle 24 is currently on pace to be the weakest sunspot cycle with the fewest sunspots since cycle 14 in February 1906.
2018 is also running close to the lowest sea ice extent in the Arctic ever for this time of year. This increase in fresh water has been linked with a slow down in the Gulf stream and an increase in Northern Latitude blocking.
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.
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.