Creme De La Creme: The Scandinavian High

[Isolated Frost]

Many regard the Scandinavian High the Holy Grail of Cold and Snow in Winter, but which ones truly delivered? More exclusive to get them nowadays it seems, but with one fringing in FI on the GFS, what is required, and where, for the most optimised cold and snow for the UK?

Them are two of my favourites looking at it, are there any like it?

[Isolated Frost]

The year after the snowiest winter in years, if not history. Not as widespread, but the cold is as powerful, especially in SE England. Icelandic HP on the face of it, but a Scandinavian High the day before, as the situation progressed.

Definitely Creme de la Creme material.

Edited February 3, 2011 by Isolated Frost

[4wd]

Wasn't the 'snowiest winter in years' 1946-7?

http://en.wikipedia.org/wiki/Winter_of_1946%E2%80%931947_in_the_United_Kingdom

Scandinavian Highs are unpredictable in what they bring, as it depends so much on where the air out east originated.

Often as not it can be just be rather cold and overcast with temperatures around whatever the North Sea is at.

[thevalley]

Hard to believe but max temps of -6c for a few days in January 1987 for the heat island of the UK Central London and -5c max and nearly a foot of snow CLondon feb 1991 . The suburbs of London Biggin Hill -12c and nearly 2ft of snow with drifts of 18ft at the airport 1987 . It really was a classic with dry powdery snow with almost blizzard like winds

Feb 91 was a gentler affair but still very potent. If we can get the Scandi High before Mid Feb then we may be in Business

[Isolated Frost]

Wasn't the 'snowiest winter in years' 1946-7?

http://en.wikipedia...._United_Kingdom

Scandinavian Highs are unpredictable in what they bring, as it depends so much on where the air out east originated.

Often as not it can be just be rather cold and overcast with temperatures around whatever the North Sea is at.

Oh my yes! Silly me!

1. 87'

2. 91'

3. 48'

Any other potent ones? Preferably the UK all under -10C upper air, OR, part of the UK under -15C upper air?

[AderynCoch]

February 1956

[cheeky_monkey]

Feb 15 1979

[Evening thunder]

Also new year 1979

So along with Feb 1979 that's two occasions of under -15C 850hpa temps in the same winter.

Not really a Scandi High but a unusually potent northerly with -15 850's in NW Scotland..

Would be interesting to find/see all the occasions of <-15 850hpa temps over the UK.

Edited February 27, 2011 by Stormmad26

[damianslaw]

Also new year 1979

So along with Feb 1979 that's two occasions of under -15C 850hpa temps in the same winter.

Not really a Scandi High but a unusually potent northerly with -15 850's in NW Scotland..

Would be interesting to find/see all the occasions of <-15 850hpa temps over the UK.

Not sure whether we managed sub -15 850hpa temps in Feb 86... anyone have the charts...

More recently though not Feb and not courtesy of an easterly I suspect we saw sub -15 temps hit parts of scotland in late Dec 1995.

Did we manage them during last December? or Jan 2010?

Feb 05 brought classic easterly synoptics yet uppers were very high for the time of year, I'm not sure whether this was because the air had originated across from the atlantic surged into svalbard and then backed down into scandi? or was it because scandi was unusually warm that year on the back of a very mild december and january and first half to Feb. I remember thinking at the time they were classic cold looking blocked synoptics but in the end failed miserable in the cold and snow stakes.

[Evening thunder]

It looks like we came close a couple of times, looking through the archive this seems to be the closest. Lots of -10C and below though.

Dec 95 is interesting in that it seems to have been the slack conditions and snow cover that lead to such low temps, during that spell around Xmas the lowest seems to have been -10 850hpa in the North. When I first saw the charts I expected the 850's to be lower.

Though it looks like -14 850hp touched the Shetlands around the 20th/21st, and the cold/snow looks like it may have hung on in the north until Xmas while a low brought milder air into the south.

I don't think any of the last 2 winters have done it, as it was something I was keeping an eye on. Might have got close to the Shetlands in that mid Dec northerly I guess.

Edited February 28, 2011 by Stormmad26

[Summer of 95]

Yet the Feb 2005 uppers weren't mild

That spell had everything, EVERYTHING required for a long cold snowy snap, except for some reason the snow mostly refused to settle at all, and at best settled for a few hours- with uppers below -10 and temps/dewpoints around -2. I still think it was the lack of frost during Jan and early Feb giving abnormally warm ground temps that was responsible.

This was the classic non-event easterly

[damianslaw]

Thanks for the above 2 posts answering many of my questions. Yes we came close to sub -15 uppers in Scotland in late Dec 1995, but it would appear to be the snow cover and very clear skies and light winds which enabled the very low temps - similiar to whapt happened in the run up to christmas last year.

I thought we were close in Feb 86, what prevented those deep cold uppers was probably the lack of any strong winds during the month pulling in steep temp gradients - unlike Jan 87 and Feb 91 when we saw a very strong easterly flow.

As for Feb 05, yes some cold uppers but as you say ground temps were very warm for the time of year hence any snow that did fall away from high ground failed to settle to any great depth which preventing and serious cold developing. Had Dec and Jan been colder I suspect we would have recorded a much colder spell of weather - indeed the synoptics in late feb 05 into March 05 were superb in terms of the being the best for sustained continental cold.

Dec 02 easterly failed on many accounts again it came too early in the season I feel with very warm ground temps and again lack of any strong winds. The air came off a mild continent in stark contrast to last nov early dec when we saw very strong NE winds off a rapidly cooling north scandinavia/west russia.

[Summer of 95]

One unfortunately I can't find the uppers for was late December 1938- like Dec 02 and Feb 05 it came after a long spell of mild weather with hardly any frost (was one of the mildest Novs on record); yet it seems to have produced both very low temps (-6 maxima in the SE) and 10-20cm+ of snow across much of the country. Perhaps if the uppers were really cold (-15C or so) and the sea unusually warm, convection was enhanced while the air still arrived in Britain well below freezing?

Edited March 1, 2011 by Summer of 95

[feb1991blizzard]

Oh my yes! Silly me!

1. 87'

2. 91'

3. 48'

Any other potent ones? Preferably the UK all under -10C upper air, OR, part of the UK under -15C upper air?

Heres one that doesnt quite meet your criteria and a rather obscure one that no one seems to talk about on here but the spell of weather as a whole did bring the first widespread disruptive snowfall to less favourable parts of the midlands since feb 1991 (4 or 5 inches to lower levels)

This chart actually only brought showers down the east and south east but then on monday morning they made their way across the south midlands southern and south west England bringing some parts their first meaningfull snow for a long time (IOW i think if i remember correctly).

The meteociel one is better. It actually shows how widespread the -14 uppers were in central southern England which is unusually cold.

http://www.meteociel...=0&map=0&mode=0

The chart below is the one that actually brought the heavy snow to many parts of britain as systems associated with the low pushed up from the south west came up against a south easterly airflow. I remember the last bit of PPN was forecast to be rain as the milder air pushed the colder air out of the way but this didnt materialise where i lived and the snow stopped about lunch time in the midlands and then cold clear weather prevailed and temps fell sharply overnight protecting the snowfall.

http://www.meteociel...=0&map=0&mode=0

Edited April 18, 2011 by feb1991blizzard