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Deep Snow please

What synoptics would we need for a blizzard like the one in America?

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Imagine you've been given access to the control centre for World Wide Weather and employed by a very rich bloke to make sure that the entire United Kingdom is blanketed in between 2ft-3ft of powder snow falling in under 36 hours. What do you do to ensure this happens, do you set an Easterly up and through some serious precip up, use a Greenland high or just dump some mad storm over the UK for the period. In addition to this it needs to thaw without causing major flooding, how do you ensure that?

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A strong high pressure over Greenland/Iceland and a polar low.

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I would say high pressure over Scandi stretching towards greenlands with low pressure approaching from Italy area bringing strong n/e winds and heavy snow showers merging into long periods of snow all blowing around and drifting in the strong wind, Severe windchill etc. Think I'm dreaming tbh 

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Its a tall order for a nationwide blizzard to the hit the UK.  We are an island and a very narrow one to boot always means somewhere will be affected by a moderating influence. I think the best synoptic for a nationwide event would be high pressure to the NW and low pressure to the south moving northwest, hard to come by, and probably has never happened before.

A polar low could do the trick, but again would have to track in an unusual way, and they are exceptionally rare...

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1 hour ago, damianslaw said:

Its a tall order for a nationwide blizzard to the hit the UK.  We are an island and a very narrow one to boot always means somewhere will be affected by a moderating influence. I think the best synoptic for a nationwide event would be high pressure to the NW and low pressure to the south moving northwest, hard to come by, and probably has never happened before.

A polar low could do the trick, but again would have to track in an unusual way, and they are exceptionally rare...

Wasn't February 91 this scenario? 

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I think the nearest UK equivalent would be a generally north-easterly regime with a strong Greenland/Icelandic anticyclone and a deep low pressure system moving east through the English Channel and then turning northwards up the North Sea.  The main issue would be marginality since the low would have warm air wrapped within its core.  A setup similar to this occurred on Boxing Day 1927.  I remember potential for a setup like that in late November/early December 2010 (the GFS's overblown low to the south that it had moving north-eastwards up the North Sea) but thinking that the projected temperatures looked conducive only to sleety stuff at low levels.

Of course there are different setups that can bring blizzards to individual regions- a strong to gale-force easterly from Russia for eastern Britain, polar lows and northerlies for Scotland and Northern Ireland, and frontal battleground scenarios for the west and south, like the blizzards in the south in January 1881 and February 1978.

 

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For this corner perhaps a channel low, or an Easterly/Northeasterly with very cold uppers.

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More shots from Princeton NJ.  Final tally was 3 foot. The place to be was Vermont, they got a lot more.. The true hero is the gur in the blue - one of the snow plough teams having a break in a diner. My friend said he'd never seen so many ploughs in one place before

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10 minutes ago, Iceni said:

More shots from Princeton NJ.  Final tally was 3 foot. The place to be was Vermont, they got a lot more.. The true hero is the gur in the blue - one of the snow plough teams having a break in a diner. My friend said he'd never seen so many ploughs in one place before

 

 

Vermont?  They got nothing from this storm!  Maybe you meant parts of northern Virginia?

 

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5 hours ago, damianslaw said:

Its a tall order for a nationwide blizzard to the hit the UK.  We are an island and a very narrow one to boot always means somewhere will be affected by a moderating influence. I think the best synoptic for a nationwide event would be high pressure to the NW and low pressure to the south moving northwest, hard to come by, and probably has never happened before.

A polar low could do the trick, but again would have to track in an unusual way, and they are exceptionally rare...

 

Not as clued up as the natives so bear with my ignorance...  But it seems to me that a better thing to hope for, rather than the OP's wish/scenario, would be for a recurrence of late November through December of 2010.  It was a sustained pattern of cold and snowfalls that lasted up until Christmas.  Sure, you didn't get a huge dump all at once.  But do you really want that?  It seems to me that a lead up to Christmas with subzero weather and some accumulations of snow from multiple systems would be the ideal dream scenario.  It's something that has happened very recently so is very much on the table.  On the eastern seaboard of the US much of this snowfall may melt in the next week before potentially facing another winter storm.  What a mess.  Why would one rather have a mammoth event lasting a few days with all the attendant headaches...When you can have a month or so of what you experienced that winter back in 2010?

In terms of the recipe for these sorts of events, historically many of the biggest blizzards affecting the Atlantic seaboard of the US have been during above avg and avg winters in terms of temperatures.  This means more fuel.   And that fuel comes from the Gulf of Mexico..basically subtropical with the Atlantic ocean (perhaps more amped than usual) being the accelerant to ignite the bigger conflagration.  The eastern half of the US just saw it's warmest December ever.  The south has been very wet this winter and that moisture gets pulled up the coast north.  Much of the US did have frigid winters in 2013-2014 & 2014-2015 but no expansive blizzards such as this.  Those winters were most notable for the temps. New England (and parts of the midwest) got walloped but that was the accumulation from several storms not one hay maker like this one.

It seems one of the problems has been for the cold temps in the UK to coincide with drier air.  But you can't realistically hope for a wintry wish list to come true if the forecasts have much of the country skirting the freezing mark.  So the first priority should be to get the temps you need.  You had the right constellation come together not too long ago (relatively speaking).  So whatever synoptics created the scenario in late 2010 that's what I would be looking out for. 

 

 

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Take a look at hisorical weather maps (on wetterzentrale) for mid-January 1881. There were some channel low set-ups interacting with record cold that produced heavy snow and very large drifts in southern coastal counties (I recall reading about this, obviously not first hand knowledge).

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Battleground has to be the one for nationwide snow. A huge low from the west meeting cold air from the east and stalling with the cold air winning out. My area does well from this set up. 

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27 minutes ago, Roger J Smith said:

Take a look at hisorical weather maps (on wetterzentrale) for mid-January 1881. There were some channel low set-ups interacting with record cold that produced heavy snow and very large drifts in southern coastal counties (I recall reading about this, obviously not first hand knowledge).

I mentioned this the other day, north of a line from the Wirral to the Humber, there was no snow from it. Trying to get a single nationwide snow event I think is almost impossible. Someone always misses out. 

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February 2009 - just one example

Very cold Arctic airflow established air over UK (result of SSW, -AO, -NAO)

Deep low pressure system approaching from SW with heavy rain and strong winds

System hits cold air and rain readily turns to heavy snow over Southern England and deposits copious amounts of snow

Some parts of London received more than 12 inches of snow!

Transport system paralysed for 24/48 hours 

Quite rare but it was brilliant!

However, it's happened a few times during the past 50 years

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The blizzard of March 2013 which affected Northern Ireland particularly badly. 

Meteorological situation

Weather_chart_march13.jpg

Image  is the weather chart for 12pm on 22 March 2013. A low pressure system is centred in the Mid-Atlantic. High pressure extends from Greenland to Scandinavia. In winter Atlantic weather systems often bring mild, wet and windy weather to the UK. Sometimes milder air comes up against cold air which is reluctant to move. Air moves in an anticlockwise direction around high pressure. The chart below shows that the most parts of the UK were under the influence of cold air which originated from Eastern Europe. Milder Atlantic air rises above the cold continental air and snow falls instead of rain.

 

The figures should be viewed cautiously as some of the worst disruption occurred in areas without Met Office recording sites, for example the east of Northern Ireland and Dumfries and Galloway. Snow depths of 41 cm at Middleton in Derbyshire and 35 cm at Darwen in Lancashire. Depths of 40 cm were reported in Northern Ireland with some areas affected by severe drifting.

As stated above there were no stations to report depths in the worst affected areas. However drifts of up to 18 feet were reported in NI. Unofficial reports suggests in excess of 2feet of snow fell in the worst affected areas and isolated areas hitting 3 foot. Here are some pics

 

article-0-18E5337B000005DC-7_964x587.jpg

 

ay_106656241.jpg?quality=80&strip=all&w=

Extremeblizzardmarch2013-22.jpg

 

Quite remarkable especially given it was the tail end of March. If this had of happened earlier in the Season.....

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Down here, I would guess a really strong high pressure belt across the north with lows approaching from the south/southwest, producing a gale force southeasterly wind with incoming heavy rain falling as snow. Feb 2009, although bringing a considerable amount of snow, didn't feature the high winds. In fact, the last time I saw anything close to a blizzard was 28th January 2004.

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Given this winter so far, I would say miracle of biblical proportions!!

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Just as a matter of interest what US cities would have similar levels of snowfall to most UK cities? - e.g. in terms of annual averages - I would probably think that the Pacific Northwest e.g. Seattle would be similar to London, Manchester, Liverpool etc.  Also I know that Charlotte that got snow as part of this storm does not get snow that often - they are at least as bad if not worse than the UK in dealing with it I think that they only get significant accumulations once or twice a decade or so and then we get Atlanta were snow is rare enough for even small amounts to give big problems.

 

Luke 

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14 minutes ago, lukemc said:

Just as a matter of interest what US cities would have similar levels of snowfall to most UK cities? - e.g. in terms of annual averages - I would probably think that the Pacific Northwest e.g. Seattle would be similar to London, Manchester, Liverpool etc.  Also I know that Charlotte that got snow as part of this storm does not get snow that often - they are at least as bad if not worse than the UK in dealing with it I think that they only get significant accumulations once or twice a decade or so and then we get Atlanta were snow is rare enough for even small amounts to give big problems.

 

Luke 

Definitely the cities of the PNW, Seattle, Portland, along with Vancouver in BC.  Similar enough climate although you have larger elevation variations.  Some years they may get only flurries and dustings of snow (near sea level where these cities and much of the conurbations are) and other years they may receive around a foot of snow in total.  Then there are the outlier years which happen at most once a decade. They have experienced big dumps of snow in the past if you go back earlier in the 20th Century.  A blizzard dumped 21 inches in Seattle in 1950 which remains the 24 hour record.  The nearest thing to that since, although not classified as blizzard, was a storm that dropped 17.5 inches over two days in 1985.  The snowiest winter on record in Seattle was 1967-68 when the airport received 67 inches in total.  But even in lean years, given the topography, you don't have to drive far in winter to find lying snow.  Mt Rainier and it's environs always receive an absolute pasting.  Same with Mt Hood in Oregon.  These two volcanoes have snow year round.  You might say it's closer to a winter in Scotland than London.

Atlanta and Charlotte are less of of an ideal comparison given the continental climate.  Atlanta averages 2.9 inches of snow a year.  Light snow isn't unusual for them but anything more than a couple inches is rare and when it does happen it creates chaos.  Although they have had to deal with ice storms in the past which are much more difficult to handle.  Atlanta can get very cold in the winter, much colder than the UK during cold snaps but usually it coincides with the drier air on the back heels of a front.  At Atlanta's location usually the moisture from the gulf ahead of the front keeps most of the moisture falling as rain or freezing rain. Charlotte averages about 6 inches (downtown) although you can find much higher averages on the western flanks of the city.  Charlotte is different than Atlanta in that they have more experience with large dumps of snow in one go, even if these don't occur every winter.  They're certainly not on the ball like the cities in the mid-Atlantic or New England up the coast but they're generally much better prepared than Atlanta.  Charlotte does have a fleet of ploughs on standby during the winter.

A few recent examples in Charlotte of storms that were much more prolific than "Jonas", just last year: https://www.youtube.com/watch?v=L-KUxs_PI8c

The biggest event in recent history was in 2004: http://wxbrad.com/10-years-ago-today-we-saw-almost-2ft-of-snow/

 

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On ‎1‎/‎25‎/‎2016 at 7:41 AM, -Bomber- said:

The blizzard of March 2013 which affected Northern Ireland particularly badly. 

Meteorological situation

Weather_chart_march13.jpg

Image  is the weather chart for 12pm on 22 March 2013. A low pressure system is centred in the Mid-Atlantic. High pressure extends from Greenland to Scandinavia. In winter Atlantic weather systems often bring mild, wet and windy weather to the UK. Sometimes milder air comes up against cold air which is reluctant to move. Air moves in an anticlockwise direction around high pressure. The chart below shows that the most parts of the UK were under the influence of cold air which originated from Eastern Europe. Milder Atlantic air rises above the cold continental air and snow falls instead of rain.

 

The figures should be viewed cautiously as some of the worst disruption occurred in areas without Met Office recording sites, for example the east of Northern Ireland and Dumfries and Galloway. Snow depths of 41 cm at Middleton in Derbyshire and 35 cm at Darwen in Lancashire. Depths of 40 cm were reported in Northern Ireland with some areas affected by severe drifting.

As stated above there were no stations to report depths in the worst affected areas. However drifts of up to 18 feet were reported in NI. Unofficial reports suggests in excess of 2feet of snow fell in the worst affected areas and isolated areas hitting 3 foot. Here are some pics

 

article-0-18E5337B000005DC-7_964x587.jpg

 

ay_106656241.jpg?quality=80&strip=all&w=

Extremeblizzardmarch2013-22.jpg

 

Quite remarkable especially given it was the tail end of March. If this had of happened earlier in the Season.....

We had 24" with that fall, yet only a few miles east they had much less, it tracked up the west side of Cumbria, and dumped copious quantities all up that side. Then the Easterly wind came and even on the lower fells there were some impressive drifts.

The ongoing, unexpectedly cold weather that weekend caught quite a few walkers out, with some serious incidents in the Lake District as a result.

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Here according to the Meto we average over 60 days of snow falling a year. Between Dec 09-april-10 it fell here in 86 days. 

Then there was this in 2010 that delivered nearly 3 foot in 48 hours

image.png

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I think some of the charts that showed up in FI for a couple of days after 4th Jan would have done the trick.

We need a lot of things to go right.....and then when they do we need a lot of things not to go wrong.

Never trust a chart that says it is going to deliver that...the only time FI isn't FI when it says it will is when it's a chart from the day before! :)

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