Cold Spell Discussion

[andy_leics22]

To be honest for the first time in my life I am happy to see milder weather again. This cold spell has been nice and it's been incredible to see the charts we have and the models runs we have but I think it's time to get back to normality again. The country needs to keep running without the problems the snow and ice has caused, a lot of people have damaged their cars and also injured themselves.

[Thundery wintry showers]

A splendid (not) piece in the Guardian G2 today educating us as to why we should all hate snow. Some of the weaker arguments in favour of snow are presented, and dismissed with an analysis of extreme examples of the inconvenience and disruption that ensues, followed by a conclusion saying, "Do say... the thaw is really coming this time. Don't say... (insert theme from "Let it snow" here)".

Not that I expect anything less from the newspapers these days!

[Iceni]

This is yuck Raining and 2.7 ° C with a direct E wind of 7 mph, but at least I can get the pressure washer out and clear the paths.

Could someone explain to me what delivers my favourite sort of snow — snows overnight, and next morning clears for a beautiful cold clear sunny day. Is it frontal snow or back-edge snow or what? It happened on the 17/18th December.

Whatever it is it's the opposite of what we've got now.

[Thundery wintry showers]

The 17th/18th December snow event was delivered an unstable east-north-easterly flow bringing convective snowfalls, and a resulting mix of sunshine and snow showers. The snow showers then cleared from most parts of the country leaving a sunny day. You can also get this from a frontal band of snow moving through overnight followed by a sunny day, but bright snowy weather is more often associated with sunshine and snow showers regimes.

Greenland High-driven cold setups are more likely to be bright and snowy because they give rise to either northerlies, or easterlies with quite a "northerly" source which are usually quite unstable, the result in both cases being an emphasis on sunshine and snow showers interspersed with occasional frontal events. This is why the period 17 December-9 January was much sunnier than average for most, and it also contributed to the excess sunshine of winter 1962/63.

In contrast setups from the Scandinavian/Siberian High tend to be very cloudy because Atlantic frontal systems push against the block bringing cloud, stable weather cloud gets picked up off the North Sea, and the southerly flow in between is often dull and damp as well. The only ways you get significant sunshine from this setup is if the high ridges over to the UK giving an anticyclonic interlude, or if it ridges to the north in conjunction with cold upper air bringing sunshine and snow showers via an easterly flow.

[Iceni]

A splendid (not) piece in the Guardian G2 today educating us as to why we should all hate snow. Some of the weaker arguments in favour of snow are presented, and dismissed with an analysis of extreme examples of the inconvenience and disruption that ensues, followed by a conclusion saying, "Do say... the thaw is really coming this time. Don't say... (insert theme from "Let it snow" here)".

Not that I expect anything less from the newspapers these days!

Snow shows up how disfunctional, incompetent and plain uncaring government authorities are (councils not gritting pavements, farmers ordered not to clear roads with tractors using red diesel, running out of salt) and it also (rather spectacularly this time) contradicted their AGW message at Copenhagen.

Very embarrassing that the only people who were able to carry on as normal or help other people out were those evil 4x4 owners. No wonder.

The Guardian can get stuffed. End of…

[Iceni]

The 17th/18th December snow event was delivered an unstable east-north-easterly flow bringing convective snowfalls, and a resulting mix of sunshine and snow showers. The snow showers then cleared from most parts of the country leaving a sunny day. You can also get this from a frontal band of snow moving through overnight followed by a sunny day, but bright snowy weather is more often associated with sunshine and snow showers regimes.

Greenland High-driven cold setups are more likely to be bright and snowy because they give rise to either northerlies, or easterlies with quite a "northerly" source which are usually quite unstable, the result in both cases being an emphasis on sunshine and snow showers interspersed with occasional frontal events. This is why the period 17 December-9 January was much sunnier than average for most, and it also contributed to the excess sunshine of winter 1962/63.

In contrast setups from the Scandinavian/Siberian High tend to be very cloudy because Atlantic frontal systems push against the block bringing cloud, stable weather cloud gets picked up off the North Sea, and the southerly flow in between is often dull and damp as well. The only ways you get significant sunshine from this setup is if the high ridges over to the UK giving an anticyclonic interlude, or if it ridges to the north in conjunction with cold upper air bringing sunshine and snow showers via an easterly flow.

Thanks TWS for that clear explanation… now I know when to get really excited and can fully appreciate the excitement on here when that beautiful Greenie high appeared — I knew it was good and meant cold.

Next question (sorry): has there ever been a Greenland/Scandi high at the same time?

[Thundery wintry showers]

Yes. A high extending across from Greenland to Scandinavia will tend to give the "high to the north" scenario that I mentioned in conjunction with the Scandinavian High, with a broad easterly flow over Britain. If the easterly pulls in cold upper air, you can expect sunshine and snow showers from that scenario. If, however, the upper air is relatively warm, with a source from southern Eurasia, then it is more likely to be cloudy with a few sleet & snow flurries in the east. There may be frontal snow towards the south if Atlantic systems try unsuccessfully to push the block away northwards.

The first two-thirds of February 1947 had an elongated area of high pressure extending from Greenland to Scandinavia, resulting in exceptionally persistent easterly winds and, for most, a good deal of cloud and some snow at times, particularly from frontal battlegrounds early in the month as lows tried to pump up fronts from the south. Winds stayed easterly in the last third of Feb 1947 as well, but the high retreated to Greenland allowing pressure to fall over Scandinavia, resulting in the coldest spell of the month with numerous snow showers but also more in the way of sunshine.

6 Feb 1947- elongated high from Greenland to Scandinavia, note the lows trying to pump up milder air from the south:

http://www.wetterzentrale.de/archive/slp/1947/Rslp19470206.gif

18 Feb 1947- still that elongated high, note the air source is from the SE implying cold cloudy dry conditions:

http://www.wetterzentrale.de/archive/slp/1947/Rslp19470218.gif

24 Feb 1947- pressure falling over Scandinavia:

http://www.wetterzentrale.de/archive/slp/1947/Rslp19470224.gif

Edited January 14, 2010 by Thundery wintry showers

[WhiteFox]

with respect, thats nonsense. im the 'mildy' on here and im fully aware that theres a return to cold next week ... winter should be mixed, in fact an ideal season should be mixed . yes i look for heat in summer, why not? is it any more unacceptable then looking for excessive cold in winter? isnt excessive cold un-seasonal even in winter? if you want that why not move to siberia?

I agree with you! Winter in the UK has never been about endless weeks like the previous four; it has always been a week or so of cold followed by a week or so of milder and wetter... This winter has been exceptional so far, but a return to westerly conditions for a while is to be welocmed by me! Most models support some sort of Atlantic influence with milder conditions and frankly it will be nice to lose the slush which has accumulated. No doubt there will be a couple of colder interludes before spring so let's enjoy whatever happens.

[aspire27]

with respect, thats nonsense. im the 'mildy' on here and im fully aware that theres a return to cold next week ... winter should be mixed, in fact an ideal season should be mixed . yes i look for heat in summer, why not? is it any more unacceptable then looking for excessive cold in winter? isnt excessive cold un-seasonal even in winter? if you want that why not move to siberia?

You just said exactly what I did from a mildies point of view. A return to cold next week, eh? Thats the first time YOU have mentioned anything about cold

next week. Mild mild mild thats all you have been going on about.

[loopydreamer]

Yes. A high extending across from Greenland to Scandinavia will tend to give the "high to the north" scenario that I mentioned in conjunction with the Scandinavian High, with a broad easterly flow over Britain. If the easterly pulls in cold upper air, you can expect sunshine and snow showers from that scenario. If, however, the upper air is relatively warm, with a source from southern Eurasia, then it is more likely to be cloudy with a few sleet & snow flurries in the east. There may be frontal snow towards the south if Atlantic systems try unsuccessfully to push the block away northwards.

The first two-thirds of February 1947 had an elongated area of high pressure extending from Greenland to Scandinavia, resulting in exceptionally persistent easterly winds and, for most, a good deal of cloud and some snow at times, particularly from frontal battlegrounds early in the month as lows tried to pump up fronts from the south. Winds stayed easterly in the last third of Feb 1947 as well, but the high retreated to Greenland allowing pressure to fall over Scandinavia, resulting in the coldest spell of the month with numerous snow showers but also more in the way of sunshine.

6 Feb 1947- elongated high from Greenland to Scandinavia, note the lows trying to pump up milder air from the south:

http://www.wetterzen...slp19470206.gif

18 Feb 1947- still that elongated high, note the air source is from the SE implying cold cloudy dry conditions:

http://www.wetterzen...slp19470218.gif

24 Feb 1947- pressure falling over Scandinavia:

http://www.wetterzen...slp19470224.gif

wow! really interesting stuff! thanks for that! you lot are so clever

[johncoolj]

Do you agree with the idea we are now in a cold cycle like the 70s .

The weather has maybe 20 years warmer winters and then 20 years of colder ones or is my idea totally wrong im no expert like you guys are on here but thats what it looks like to me

I think looking at charts which seem to change a lot every day that we will have mild weather from the west for the next 2 weeks with maybe 3 days of east winds if we are lucky

Edited January 14, 2010 by johncoolj

[johncoolj]

[hey micheal fish says cold weather will come back look here is he wrong

http://www.netweather.tv/index.cgi?action=michaelfish;sess=

does the latest model support his idea

[Thundery wintry showers]

I agree with you! Winter in the UK has never been about endless weeks like the previous four; it has always been a week or so of cold followed by a week or so of milder and wetter... This winter has been exceptional so far, but a return to westerly conditions for a while is to be welocmed by me! Most models support some sort of Atlantic influence with milder conditions and frankly it will be nice to lose the slush which has accumulated. No doubt there will be a couple of colder interludes before spring so let's enjoy whatever happens.

This is certainly one area where I'm in 100% agreement with Mushy (though that said, if we get a mixed spring, you can bet money that Mushy will be the first to complain whenever we get an Arctic outbreak with sunshine and snow showers- a weather type which, like it or not, is part and parcel of a variable spring!). Variety means something for everybody, though admittedly, more for those who thrive on variety than those who thrive on homogeneity.

I noted in the "how much can you cope with?" thread that this winter has taught me a lot about how much cold/snow I can tolerate. Until this winter, I always thought it would be 7 days max before I started hoping for a pattern change. The last 4 weeks have shown me that I can tolerate bright snowy weather for weeks on end- but this week is showing me that with cloudy snowy weather, 7 days max is about right...

[Optimus Prime]

This may well have been a severe winter with excessive snowfall here in the south. And yet the SE didn't grind to a hault, didn't suffer very much and everything went (comparible to what everyone was saying prior to December) on like it would have done in the 60s.

I've always protested about the hypothesis that the SE can't cope with a severe winter in modern times. This and Jan/Feb 2009 proves it can by a long shot. And conditions this month aren't too dissimilar if not worse to 1963.

[andy_leics22]

*waves goodbye to the snow he has left*

[johncoolj]

so what is going to happen will we have the east winds for long or only a few days it looks like west for the next 2 weeks

[Strider]

I like how Netweather say that Michael Fish was "snowed in" so he couldn't make his weekly forecast last week... it must have been really bad where he is if he couldn't make it to his living room :unsure: :unsure:

[Eugene]

Nothing beats a snow covered landscape, there is just something so beautiful about it and i can't understand why people want it gone so we can have wet windy weather back, nice extended cold spell we've had with lots of sunshine since mid Dec(look at the sunshine records for that) with people out and about enjoying the cold/snow, now with all the rain likely after mid next week it will be too wet for people to go out and enjoy it the outdoors and people will be indoors more.

[Osbourne One-Nil]

I'll safely reach 30 consecutive days of complete snow cover at home, although just 5 miles away in Appleby, the cover is much patchier and probably down to just 50%. Proof what a little bit of elevation can do and compared to recent winters, a fairly remarkable achievement!

[Iceni]

Nothing beats a snow covered landscape, there is just something so beautiful about it and i can't understand why people want it gone so we can have wet windy weather back, nice extended cold spell we've had with lots of sunshine since mid Dec(look at the sunshine records for that) with people out and about enjoying the cold/snow, now with all the rain likely after mid next week it will be too wet for people to go out and enjoy it the outdoors and people will be indoors more.

Me neither. I don't care what it's like so long as it's cold enough for overnight frosts. I've taken to calling winter the mud season around our part of the world — but an overnight frost means I can go for a walk without slipping and sliding around and I don't have to wash floors every other day.

[Thundery wintry showers]

I mentioned in a couple of other related threads that another thing that kept me interested for most of this cold spell was the frequent convection off the North Sea. I often find the convective potential even more exciting than the snow itself- in these North Sea areas it's the closest you can get to those summer convection/thunderstorm scenarios at this time of year.

People are already indoors a lot more at UEA, where we have rapidly disappearing slush and it's dull cold and wet- whereas until the end of the weekend there were always lots of people out and about, particularly around the hills which regularly had groups of people sledging down them.

[Strider]

Me neither. I don't care what it's like so long as it's cold enough for overnight frosts. I've taken to calling winter the mud season around our part of the world — but an overnight frost means I can go for a walk without slipping and sliding around and I don't have to wash floors every other day.

I can't stand having to clean the mud off my trainers every time I go for a walk

Cold, hard grounds make walking on much better.

Back to the mud this weekend though

[rbw]

This may well have been a severe winter with excessive snowfall here in the south. And yet the SE didn't grind to a hault, didn't suffer very much and everything went (comparible to what everyone was saying prior to December) on like it would have done in the 60s.

I've always protested about the hypothesis that the SE can't cope with a severe winter in modern times. This and Jan/Feb 2009 proves it can by a long shot. And conditions this month aren't too dissimilar if not worse to 1963.

Was this a severe cold spell or not? I remember many years from the 70s when when we regularly had 5 inches of snow as we did this year. We have had 10 days of snow cover which is longer than I'm used to but 7 days isn't that rare (even since 2000). Temps of -9C happen every three or four years whereas this year we had a -12C but that coincided with snow cover. To me in my back yard I would use the term moderately severe. What do others think?

[Osbourne One-Nil]

Three consecutive nights below -12C and tomorrow will be the 30th consecutive say with complete snow cover in the garden. I'd consider this a pretty severe cold spell.

[damianslaw]

Three consecutive nights below -12C and tomorrow will be the 30th consecutive say with complete snow cover in the garden. I'd consider this a pretty severe cold spell.

Yes I agree its been a notably cold spell here. We saw 7 days with sub zero temps between the 3rd and 9th January, something we saw in Dec 1995, however, compared to that spell this one doesn't rank anywhere near as severe for cold nighttime temps. The lowest we have seen in this spell is -10 degrees, compared to -18 degrees in Dec 95, though I have to say that spell was preety exceptional.

Whats more worthy of note is the last time we managed to see a maximum of 6 degrees or more - which is the normal average max for late dec/early jan, I think the last date being the 11th December.