Europe January 2020 Outlook (Look back a Nov/Dec 19)

Written by on January 6, 2020 in Rest of Europe, United Kingdom & Ireland with 0 Comments

November and autumn 2019 ended cold across Western and Northern Europe but winter’s opening month was largely milder than normal across much of the continent.

November as a whole was colder than normal from Morocco, Iberia up through the British Isles and Ireland to Scandinavia. It was likely coldest for the UK since 2016 but for Scotland and particularly the Highland region it may have been coldest since 2010.

Nights in November dipped below -30C over northern parts of Scandinavia while even Scotland endured two nights at -8C in Glasgow while Tulloch Bridge (Fersit) hit -10.2C (coldest November low since -12.6C was reached at Braemar in 2016).

Meanwhile central and east Europe essentially roasted in record warmth. Chisinau, Moldova started November cold with a high of -1 and low of -8C but a mere 7 days later the thermometer reached 23C which was the Moldovan capital’s warmest ever November day.

November temperature anomaly.

 

Credit: Michael Ventrice

On the same morning the Highlands dropped below -10C, the Southern Uplands was almost equally as cold as my dash read -9C between Elvanfoot and Abington.

Mark Vogan

Mark Vogan

So it’s been a seasonal transition of extremes with chilly November but warm December.

December temperature anomaly.

Credit: Michael Ventrice

Strong polar vortex

Blame a strong polar vortex for a warm Europe and intense polar cold bottled within the arctic and subarctic. The bundled up cold has driven temperatures over Alaska and Greenland into the -50s and -60s celsius. This is in direct consequence of a strengthening polar vortex which in turn leads to stronger westerlies and mild ocean influence over Western Europe.

Strongest/coldest stratospheric polar vortex in 40 years!

Temperatures within the core of the polar vortex has been measured at -96C or -141F above Reykjavik, Iceland as seen within the dark spots in the below image captured January 3rd.

Credit: Andrej Flis

Credit: Andrej Flis

Winds circling this super polar vortex have been clocked at up to 372 mph.

Credit: Andrej Flis

The intense cold pool and extreme winds circling is driving the extreme cold over parts of the polar region and in turn driving a strong Atlantic jet stream.

Warmest December day for Britain is followed by warmest January day for Norway, Alaska shivers coldest air since 2012

Due to the exceptional strength of the PV creating a deep arctic trough but consequential strong Europe high, the southwest to northeast oriented Atlantic jet stream brought astonishingly mild air into Northern Europe for the closing days of December.

The powerful jet stream roaring out of the SW at 40,000ft between deep low and strong high coupled with warm sector southwest winds beneath aided warmth into Scotland more associated with the subtropics at this time of year.

Iceland on the cold side of the jet has been getting hammered by severe gales and blizzard conditions, 1,000 miles south and east and temperatures of +10-14C covered the UK.

The downslope foehn effect helped boost temperatures beyond to mild to downright balmy over the Highlands.

Credit: Scott from Scotland

Up first for the ridiculous warmth was the village of Cassley in the central-north Highlands which recorded a 3AM temperature of 16.8C. According to the Met Office, this is the UK’s warmest temperature for so late in the year.

Then on December 28th under the same conditions but with the aid of sunshine, Achfary, Highland soared to an astonishing 18.7C which surpasses the previous UK December record of 18.3C recorded at Achnashellach back in December 1948.

The exceptional warmth even extended into Scandinavia where the village of Sunndalsora, Norway touched 19C or (66F). That’s 25C ABOVE NORMAL and makes it the country’s warmest January day in recorded history.

Greenland and Alaska shiver beneath the strong vortex

Meanwhile, beneath that powerful polar vortex, Alaska has shivered to -53.9C or -65F which makes it the lowest reading in Alaska since 2012 when it hit -66F.

While it was cold in Alaska, it was even colder on central Greenland’s icecap. The thermometer on the morning of January 3rd dipped to an incredible -66C or -86.8F. The all-time record remains at -67.2C or -88.96F set in March 2011.

Another plume of exceptional warmth accompanies the wind and rain of this week

While a strong Atlantic jet stream continues to drive lows towards Iceland, the UK shall continue to endure wet, windy and mild air weather this week.

As well as strong and gusty winds and heavy persistent rain at times, VERY mild air shall once again get pulled some 1,000 miles from the Azores, potentially driving temperatures to between 12-14C widely to the EAST of the Grampaisn, possibly even 16C somewhere along the Moray or Aberdeenshire coast.

As you can see for the below charts, the jet stream rips over Scotland from the SW and so heavy rain and 50-70 mph winds shall impact west and central areas but vertically stacked and dried out DOWNSLOPE winds north and east of the Grampians with the aid of brighter skies should significantly boost temps.

Credit: wxcharts.eu

Credit: wxcharts.eu

All-time UK January records

January 18.3 10 January 1971 Aber (Gwynedd)*
January 18.3 27 January 1958 Aber (Gwynedd)*
January 18.3 26 January 2003 Aboyne (Aberdeenshire)
January 18.3 26 January 2003 Inchmarlo (Kincardineshire)

Any cold weather on the horizon?

By taking a quick and dirty glance at the AO and NAO ensemble charts you can see why it was a cold November and why so warm now.

As we go ahead through the remainder of January based on current conditions and future model projections, I believe brief cold shots are about as good as we can expect. These cold shots are most likely behind lows.

A strong vortex and speedy westerlies driving lows in off the Atlantic make it hard to imagine any meaningful winter weather is on the way. In truth, any change in the strength and position of the vortex is a must to support real winter. Modelling sees warming and weakening of the polar vortex but at the moment, to project colder is mere wish casting. I’ve done it time and time again and will not do so this time.

Long range modelling has been pretty spot on so far this winter with a strong +AO/NAO and until we see significant changes actually take place, i see the overall mild theme continuing.

Another thing worth pointing out is that even if we get a SSW, this DOESN’T mean we WILL see a colder pattern. The type of strat warming and where the vortex splits is key.

Modelling does suggest a weakening or displacement of the polar vortex out towards the end of the moment but this is likely to favour a much colder pattern for North America but NOT Europe I’m afraid.

Here’s the initial 10mb temps now over the pole. Note warming on Asian side?

Credit: Tropical Tidbits

BTW that cold pool concentrated over the North America and Europe side of the pole might as well say low pressure down at 500mb meaning ATLANTIC remains the driver.

By day 10 the warmth has gone and the vortex is strong!

Credit: Tropical Tidbits

Even out to January 22 and sure the vortex may be stretched, possibly split but likely driving true polar air into North America. That 10mb temp profile over Greenland and Europe supports an Iceland low, Europe high. Exactly what we’ve got now.

Credit: Tropical Tidbits

That setup above pretty much reflects this week’s 500mb setup below.

Credit: Tropical Tidbits

So, the rest of January? Much of the same as we’ve had with BRIEF spells of colder.

Here’s the CFSv2 500mb setup for February. The same…

Credit: Tropical Tidbits

The return of the North Pacific warm pool favour’s Alaskan ridging and colder times for central and eastern North America during the 2nd half of winter but the North Atlantic isn’t favourable for a Greenland block.

Credit: NOAA

If anything changes, I will let you know right here!

FEATURED IMAGE CREDIT: Highland Defenders 

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