Welcome to my 12th annual winter forecast for Europe. In this forecast, the conclusions drawn for the upcoming 90-day meteorological winter period are based on current solar, ocean and atmospheric drivers and my understanding of their potential influence.

Of course, pinpointing any specific pattern several weeks or months ahead is near impossible but we can provide potential trends and likelihoods.

Based on the research carried out in producing this forecast and taking into consideration all the current players, in terms of current solar state and ocean anomalies, 2021 has strong similarity with 2010. So, in essence I believe we have our best chance at a proper winter since 2010 but I must stress, that DOESN’T mean the exact same winter as 2010-11.

The Drivers

Here’s a breakdown at what drivers we have at play this year.

Solar Minimum

The most recent solar minimum occurred at the close of 2018. The previous solar minimum occurred in 2008. About 18 to 24 months AFTER the 2008 minimum, the UK, Ireland and Western Europe witnessed it’s coldest winter since 1978-79. 2009-10 was followed by the UK’s coldest December in over 100 years. It’s long been believed that there’s an increased chance of high latitude blocking and colder winters through the mid latitudes following a solar minimum.

It’s now 18 to 24 months after the 2018/19 solar minimum (same time frame as the 2008 minimum) and of a similar level and strength to the previous solar cycle. Taking into consideration the type of winter we had following the 2008 minimum, I would expect to see increasing chances for a colder winter in 2021-22.

What makes 2021 more comparable to 2010 rather than 2009 is the La Nina. In autumn 2009 we had an El Nino.

IF the sun and earth’s atmosphere is as linked as many scientists believe, then here comes a big test this year.

Arctic Sea Ice Extent

While still below average, Arctic sea ice extent is about as healthy as anything seen in much of the last 10 years.

This year’s increase in ice coverage compared to recent years has appeared to have provided a healthy reservoir of polar air available to tap compared to recent years.

Global sea surface temperature anomaly

While global ocean temperature fluctuates year by year and decade by decade, there is an interesting tendency for the development of a ‘horseshoe of cold’ over the North Pacific during and the immediate years following a solar minimum while it’s often warm around the time of a solar maximum.

While solar cycle has strong correlation between 2021 and 2010, the similarity in global SSTA’s (sea surface temperature anomaly) is most striking.

Autumn 2010

Autumn 2021

In simple terms, I’ve discovered a warm North Pacific and ‘colder’ North Atlantic enhances cold opportunity over North America but the temperature imbalance created off eastern North America tends to enhance the Atlantic jet and fire more storms, less cold air into Western Europe (+NAO).

A colder Pacific, warmer Atlantic can help lead to a colder Alaska, stronger Aleutian low and downstream weaker Atlantic jet increased chance for Atlantic rather than Pacific blocking (-NAO)

La Nina (east based)

The La Nina has been a pretty ongoing event over the last couple of years in the Pacific Basin and likely allowed the cooling of the PDO (Pacific Decadal Oscillation). While the La Nina dissipated during the past summer, it returned during autumn and has become firmly east based.

La Ninas tend to turn down earth’s thermostat and has been known to bring front loaded winters to Europe. 2010-11 is a perfect example of this with extremely cold late November, December followed by much milder January and February.

Quasi-Biennial Oscillation (QBO)

I believe last winter could have been a much colder one had it not been for the west QBO.

This year, it’s negative which correlates to ‘easterly winds’ blowing over the tropics. 2021-22 looks to be the first east QBO winter since 2017-18 (year of the ‘Beast;). This can, but not always, lead to a weaker polar jet stream to the north and allow the atmosphere to build pressure over the higher latitudes. An east QBO can also help weaken the polar vortex.

Last year

This year

Importantly, the easterlies have now descended below 50hpa as can be seen in the graphic below.

This means easterlies dominating the lower stratosphere/upper troposphere and this is more likely to have influence on our weather as we head deeper into the winter months. This also coincides with the east based La Nina which is also good to see.

Indian Ocean Dipole (IOD)

In 2019-20, we observed a record strong +IOD, it’s believed that this may have helped drive a record strong polar vortex and in turn, one of the UK and hemisphere’s warmest winters.

As you can see, the IOD was weakly positive last autumn and winter but it’s been quite negative during autumn 2021. A negative IOD during the autumn tends to be a positive indicator for a possibly colder winter.

Polar Vortex (Stronger than expected)

During early October, the stratospheric polar vortex weakened significantly and raised hopes for early season cold during November and December.

A strong vortex tends to promote low pressure over the pole, higher pressure through the mid latitudes and often a strong westerly or zonal jet stream in between.

A weak vortex tends to allow higher pressure over the pole to push polar air, jet stream and lows further south as the below graphic shows.

Despite the building to a now healthier stratospheric polar vortex, the setup is not clear cut as the tropospheric polar vortex has remained weak up until now. The disconnect between troposphere and stratosphere means colder spells remain possible as the weak ‘lower vortex’ has short term and more direct influence on our weather compared to the upper vortex. The weak ‘lower polar vortex’ is likely responsible for the late November cold spell and North Atlantic blocking.

As we progress through December the question will be, does the upper (stratosphere) polar vortex remain healthy and perhaps begin to strengthen the lower (troposphere) polar vortex or will the stratospheric vortex weaken as some models suggest?

As of this writing, there may have been a connection between stratosphere and troposphere and this may well keep the westerlies stronger.

Madden Julian Oscillation (MJO)

GIVEN THE STRONG POLAR VORTEX, THIS COULD BE CRUCIAL…

In short, the MJO is a wave of enhanced convective energy which circles the tropics. This can have significant influence on the global weather pattern.

When in certain phases/positions (5, 6, 7), it can enhance the probability for colder weather over Europe, North America and Asia by driving heat into the high latitudes, forcing blocking highs to draw arctic air southward. Other phases (1, 2, 3 and 4), it can have the opposite effect. Other times, it has little influence altogether.

As of this writing, the MJO is expected to rotate out of the warm, less conducive phases and through phases 6 and into 7 (west Pacific) towards mid-December.

With a more amplified phase 6 and 7 MJO combined with east QBO as well as east based La Nina, this raises the possibility for blocking during the 2ND HALF OF DECEMBER. However, ‘where’ any high set up, will be key.

While the polar vortex ISN’T looking particularly favourable at this time, there is a very healthy arctic reservoir which is bringing extremely cold temperatures to the northern continents as can be seen below.

Here’s a view arctic surface temperatures from above for December 23rd!

This set’s the stage for some proper arctic air to get involved with the mid latitudes if we can get heights to rise northwards.

Concerns

Despite, arguably the best global SSTA profile-solar state with east QBO combo since 2010, there are still some nagging concerns.

The planet’s atmosphere and ocean is warmer than a decade ago. I cannot ignore the strength of the polar vortex and for now, it looks like we’ll need to rely on the MJO for the freezer door to open.

Reason for optimism

Just because the stratospheric polar vortex is healthy and compact for now doesn’t mean it shall stay that way. In the models there are some rumblings of a split later in December and given the solar state and possible pressure put on by the MJO, even strengthening of the Siberia high which have boosted surface temperatures to -55C and east QBO, there is still optimism for weakening, displacement or even a sudden stratospheric warming.

It can also get cold WITHOUT the vortex being weak!!

Mark Vogan’s 2021-22 Forecast for Europe

Based on all of the above and with a lot of thought put in, here’s my verdict.

December 1-10th is dominated by Atlantic low pressure with a largely polar-maritime air flow influencing. Between lows, clear, calm skies provides modestly frosty nights, especially for Scotland. A deepening low will provide stormy conditions for the 7th to Ireland, Northern Ireland and western Britain in which localised damage and disruption is likely. MUCH of the continent remains cold or very cold, especially so for Northern Europe where temperatures have dropped below -40C in Sweden!

December 10-20th, the jet stream remains active and influential on Ireland, UK and near continent (France/Low Countries) but an area of high pressure looks to build north over the UK bringing drier and more settled weather with cool days, frosty nights.

Much of the North and East of Europe should remain colder than average.

December 20-31st ‘may’ see high pressure lift either north, northeast or northwest of the UK, I expect at the very least, a cooling trend with the return of colder source winds arriving indicative of the MJO phase 7. Best or worst case, the high builds enough west or northwest of the UK, providing a -NAO signal which allows the freezer door to open in the run up to Christmas and or New Year.

Timing of any impending cold is going to be crucial and more often than not, it’s often delayed.

White Christmas for UK? I’ll call it a 50-50!

January 2022

Based on all the drivers discussed above, if we are going to see a real winter, it is likely to arrive in January. I believe this winter has great potential and I also believe a weakening, split or collapse of the polar vortex is still very much on the table despite it’s strength now.

So, if there’s to be a major ‘polar vortex’ induced arctic outbreak this winter, it’s likely to occur mid to late January which could challenge the -23C recorded at Braemar, Aberdeenshire last February and this cold may linger on into early February. If there’s no such weakening of the vortex, I still think a significant cold spell lasting 5-7, possibly 10 days will impact the UK and Ireland. If there’s no such love from the polar vortex, cold and mild will come and go, likely with the eastward progression of the MJO.

There will be milder periods of course, likely early January or during the 1st half of the month following a possible cold spell in the run up to Christmas and or New Year. In other words we get a 1, possibly 2.2.5 week spell of milder.

February 2022

Coldest month of all? I guess that depends on January and whether the cold hits and how strong. Either way I believe a further 1-2 spells of winter hits during February with the most disruptive snow of winter hitting.

As for Europe, I believe it’s an overall cold winter with brief spells of mild. The Med countries could see unusual warmth at times. The most changeable region for mild and cold will be the UK down through France and into Iberia.

Monthly temp anomaly breakdown for UK/Ireland

December: Near to slightly below average

January: Slightly below average

February: Below average

STAY TUNED: THIS PUBLICATION IS SUBJECT TO MINOR CHANGES IN THE COMING DAYS

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