Winter Model Discussion - Cold Hunting - 20th Dec

[Sweetdream]

I have a customer who runs our local highways gritting depot, he said to me last week there's a high chance of a cold possibly snowy jan/feb, I asked how he knew this, he said it had come from a superior & that they were ready....

Hi slightly of topic but the H.A get their updates from the met. I know this as my partner has worked for them for the past 11 yrs and in winter he is on call for winter maintainace (ie) gritting the major roads. So many times have they been given wrong info. Thanks to you guys I am able to give him advanced warning.

[Cecil Hogmanay Melchett]

Dec has just got worse and worse as its gone on,and it almost certianly will end a completely snowless month for many.The real worry is the pattern looks well set to head into the New year and im at a loss to see were any cold is going to come from.What is driving this conveyor of Atlantic lows,its becoming ridiculous.

[Methuselah]

Hi slightly of topic but the H.A get their updates from the met. I know this as my partner has worked for them for the past 11 yrs and in winter he is on call for winter maintainace (ie) gritting the major roads. So many times have they been given wrong info. Thanks to you guys I am able to give him advanced warning.

Hopefully, the current warnings will be better than the last one?

[liam300]

Does the Models consider the stratosphere?

If so the stratosphere doesn't mean anything for the UK

[Summer Sun]

A long time since we saw charts like this!

[bluearmy]

Does the Models consider the stratosphere?

If so the stratosphere doesn't mean anything for the UK

Yes liam, the model runs do the strat and trop at the same time - they are interlinked and you can't just stop where the two meet! That's why you get to see strat forecasts from the gfs runs and the following morning from ECM 12z.

[syncmaster]

Genuine question it is always been led to believe that as soon as models go to lo-res part of the run ie GFS they default to a zonal chuck out anything type of situation, my question here

is why when thats the case do people take it as gospel thats how its goin to carry on seems all of a sudden we have a double standard goin on!!!! now if the models cant get to grips properly

with a few days ahead why assume they re correct in FI its got to be very confusing for new people taking up this hobby when u have members touting things that are impossible to backup

now i have no preference to what happens personally but i like realism as i say if the models struggle at shortrange how can u expect them to have a clue at 10 days plus.. yet some people

seem to think they KNOW..

[liam300]

Genuine question it is always been led to believe that as soon as models go to lo-res part of the run ie GFS they default to a zonal chuck out anything type of situation, my question here

is why when thats the case do people take it as gospel thats how its goin to carry on seems all of a sudden we have a double standard goin on!!!! now if the models cant get to grips properly

with a few days ahead why assume they re correct in FI its got to be very confusing for new people taking up this hobby when u have members touting things that are impossible to backup

now i have no preference to what happens personally but i like realism as i say if the models struggle at shortrange how can u expect them to have a clue at 10 days plus.. yet some people

seem to think they KNOW..

Got to agree. We couldn't see any real consistency from 3-4 days let alone FI.

[Weathizard]

A long time since we saw charts like this!

Typical, not bad sypnotics..... For summer, least its less zonal that some runs and would give flood affected areas time to recover slightly.

[Jason M]

Crikey, at 156 on GFS we have a Spanish plume into Germany with widespread uppers of 12C. Remind me, what season is it?

Jason

[cooling climate]

Thought I would mention this in here as it may have some relevence to us

in the UK. Larry cosgrove a respected meteorologist in America in his latest

weather America newsletter talks of numerical models showing a steadfast -EPO,

AO and NAO going into the first week of January.Also much of the states could

be in the freezer through to valentines day.

This sounds to me like a strong +PNA,-AO and NAO signature which would bode

very well for the UK as well. Whether is there is any merit to all of this we

should know over the coming days model watching.

[UV-RAY]

Some almost springlike charts out in FI now, at least there could be some drier weather for those already flooded. Lots of straw clutching with regards to SSW, remember just because we may get a warming event it doesn't equate to cold here all the time.

[alexisj9]

I have a customer who runs our local highways gritting depot, he said to me last week there's a high chance of a cold possibly snowy jan/feb, I asked how he knew this, he said it had come from a superior & that they were ready....

Well at least it will still be there for next year if it does turn out as wrong info, and the councils can spend the money they spend on salt on something else.

[TEITS]

Thought I would mention this in here as it may have some relevence to us

in the UK. Larry cosgrove a respected meteorologist in America in his latest

weather America newsletter talks of numerical models showing a steadfast -EPO,

AO and NAO going into the first week of January.Also much of the states could

be in the freezer through to valentines day.

This sounds to me like a strong +PNA,-AO and NAO signature which would bode

very well for the UK as well. Whether is there is any merit to all of this we

should know over the coming days model watching.

Looking at the GEFS mean I cannot see any sign of a negative NAO quiet the reverse.

http://modeles.meteo...-21-1-384.png?0

Have to say I continue to be very sceptical of these long range predictions. I prefer to see the evidence in the actual model output. I remember GP a few days ago mentioning a negative NAO for the end of Dec and that clearly isn't going to be the case.

The model output will improve because frankly it couldn't get any worse. However with regards to the pattern change in Mid Jan and again I would advise members to be cautious until we actually see this in the model output at a sensible timeframe. I will also add that for any hope of the pattern change occuring in mid Jan then you need the Met O to continue to predict this. I disagreed with the Met O with regards to their Xmas/New year forecasts but I was proved wrong. Just goes to show im an amateur and they are the pros!

Edited December 23, 2012 by THE EYE IN THE SKY

[nick sussex]

Thought I would mention this in here as it may have some relevence to us

in the UK. Larry cosgrove a respected meteorologist in America in his latest

weather America newsletter talks of numerical models showing a steadfast -EPO,

AO and NAO going into the first week of January.Also much of the states could

be in the freezer through to valentines day.

This sounds to me like a strong +PNA,-AO and NAO signature which would bode

very well for the UK as well. Whether is there is any merit to all of this we

should know over the coming days model watching.

Unfortunately the models don't seem to be listening because upstream its as flat as a pancake and we end up in a positive NAO.

Indeed on Friday NOAA went with pretty much the same, neg AO and NAO and positive PNA with the neg AO returning to a more typical type pattern.

Which looks nothing like the dismal output we see today!

[UV-RAY]

Looking at the GEFS mean I cannot see any sign of a negative NAO quiet the reverse.

Have to say I continue to be very sceptical of these long range predictions. I prefer to see the evidence in the actual model output. I remember GP a few days ago mentioning a negative NAO for the end of Dec and that clearly isn't going to be the case.

The model output will improve because frankly it couldn't get any worse. However with regards to the pattern change in Mid Jan and again I would advise members to be cautious until we actually see this in the model output at a sensible timeframe.

I think that teleconnections have been pretty poor for our part of the world upto now and any talk of cold in mid January is looking unlikely given the current output.

[Weathizard]

Can't post charts as I'm on phone but I take your 0z for turdness and raise it with the 6z at 204! Even the strat warming/cold core is significantly worse.

(Cold weather prospects wise)

Edited December 23, 2012 by Weathizard

[Methuselah]

I doubt that there's any point in looking for any SSW-influences, just yet?

As far as I understand it (not a lot!) any effects of stratospheric warming will not appear in the models until such time as they manifest in the sort of data that the models actually can process...As a result, all the models will be 'blind' - in the near-term...

Now let's see how long that prediction survives!

[TEITS]

I think that teleconnections have been pretty poor for our part of the world upto now and any talk of cold in mid January is looking unlikely given the current output.

The only thing I will disagree with you is you cannot make any assumptions for mid Jan when +384 is the 8th Jan. As for Teleconnections and I agree they have been very poor and without meaning any disrespect some of the predictions in the Stratosphere thread have been way off. I do believe Teleconnections/Stratosphere is the future of forecasting but we are a long way away from understanding these and making accurate predictions.

The 06Z is like watching a horror film!

[Luke Best]

Slightly off-topic (sorry mods) but I read the following piece (written in 2003) on the TWO website and I think it serves as a timely reminder that we can trawl through model output all day long 'hunting for cold' but every now and again cold will simply arrive 'out of nowhere' (and this is true even now with powerful supercomputers churning through all of the available data).

Record Cold Spell of 1987: How It All Started

It is well accepted that the most severe spell of weather in southern England since the 'Little Ice Age' occurred in the unlikely year of 1987 in an otherwise 'average' winter.

So what brought about such a severe spell and why did it end as quickly as it started.

The story begins in the first few days of January 1987, looking at the surface chart a cold spell seemed miles away as a strong High of 1032mb sat over Spain with the U.K. and Western Europe in a strong Westerly flow, temperatures through most of Europe were above normal, however in Scandinavia and Northwest Russia it was intensely cold.

The first change occurred quickly on the 2nd as the Iberian High shifted Westwards and low pressure transferred into the North Sea, a brief Northerly swept south across the U.K. but it was hardly cold.

By Sunday 4th High pressure was back over France with the U.K. in another mild flow, however by now the models thought something was up and on the Countryfile forecast on the 4th the forecast was for a short but very cold Northeasterly outbreak mid week as low pressure crossed Holland. The models however predicted that the Arctic outbreak would be short and that milder westerly winds would take over again by the weekend.

The short cold spell was in fact a non-event as rising pressure over Ireland killed off the Arctic Airflow and by the 7th High pressure was centered over the Irish Sea and the weather cool and quiet.

By the 7th the models still couldn’t decide which way things were going to go and the Met. Office remained silent about prospects for the weekend.

Things then moved very quickly, a deepening low moved south across Norway on the 8th and into Germanyby the 9th and behind this low there was a massive rise in pressure over Scandinavia. At the same time a large pool of intensely cold air had swept out of Western Russia and was crossing Poland and East Germany, at last the models could see what was going to happen and early on the 9th the message went out: 'Very Cold later in the weekend'.

Meanwhile pressure continued to rise over Scandy reaching 1040mb over Finland by the 10th. Sub freezing air reached Eastern England on the afternoon of the 10th and this very cold air reached all areas by dawn on the 11th.

The Countryfile Forecast on the 11th was a 'classic' John Kettley saying "The only bright thing on this forecast is my tie!" He rightly predicted freezing temperatures and blizzards all week although even now the depth of the cold was being under estimated.

During the day temperatures kept on falling as snow showers became more intense, Monday 12th was probably one of the most remarkable days of the 20th Century as temperatures stayed below -5c throughout England and below -8c in several places in the home Counties.

The Weather Log for Jan. 1987 describes the 12th-14th as the coldest spell of weather in southern Englandsince January 1740.

Over the next few days the U.K. was swept by blizzards and freezing temperatures as an upper cold pool crossed England.

The models showed no sign of a break in the weather and on the Countryfile Forecast on January 18th the forecast was for a very cold but drier week, however within 24 hours this forecast went wrong.

During the 19th a warm front crossed the U.K. cutting off the continental feed and high pressure then formed in the warm sector.

By the 20th temperatures of 4c-6c were recorded over most parts and a steady thaw began. The next 10 days were dull and sunless the severe spell becoming a distant memory.

The interesting thing about the cold spell is the poor performance of the forecast models even up to +72 hours, O.K. computers are better now but I still think they would struggle with a similar chain of events.

In a 'New Scientist' Article of July 1987, a group of climatologist speculated that the Jan 1987 cold spell was partly due to GW and we could expect more frequent severe spells in the future!

That seems an awfully long time ago.

© Andy Woodcock, Jan 2003

So let's not get too down at the sight of a few blowtorch charts in FI, you never know what might be just round the corner. And finally, some eye candy from the height of the January 1987 episode:

From this:

To this:

[If Wishes made Weather]

Clearly quite horrible charts for cold weather this morning following on from yesterday's concerning charts which dampened what had been some encouraging signs a little further out. One way or another, I think we must now state that there is little chance of anything cold by the end of the month, so that is 1/3 of the winter gone. If, and it is not certain, the predicted Strat warming leads to colder weather over the BI then this could kick around half way through winter. That isnt to say that it isnt fascnating for its own sake though. The positive is that to some degree, the Dec-Feb definition of winter is skewed and in truth, March can, and is often, colder than December although it officially is recognised as spring.

[Mr Frost]

Had to double take on the name of this thread, thought I had stumbled across a Stratosphere bashing one. Not much to look forward to currently from a coldies view. However, we all know how unreliable the models have been over the past couple of weeks so who knows really what is going to happen come January. Although, going by what is being posted in here most seem to know exactly what will happen. Bizarre indeed. Have a fantastic Christmas everyone! Let's hope us snow lovers have something to cheer about after New Year.

[Bobby]

I doubt that there's any point in looking for any SSW-influences, just yet?

As far as I understand it (not a lot!) any effects of stratospheric warming will not appear in the models until such time as they manifest in the sort of data that the models actually can process...As a result, all the models will be 'blind' - in the near-term...

Now let's see how long that prediction survives!

I'm pretty sure the models do take into account the stratosphere, I heard it mentioned last year, at least to some degree.

If you're a cold lover don't even look at the 06z, nightmare.

[johnholmes]

I'm pretty sure the models do take into account the stratosphere, I heard it mentioned last year, at least to some degree.

If you're a cold lover don't even look at the 06z, nightmare.

not in the 2x and 4x daily synoptic

the ONLY data is the actual or assigned data at the start, 00, 06, 12 and 18z nothing else at all. The models then chunter away using the basic physics and complex maths to give the charts we see.

If you doubt that explanation then google uk met and NOAA, or send UK Met an e mail and ask if their synoptic models, as opposed to their climat models do different to what I've suggested

That said then I am unsure of what the top level is in their main model, it quite probably goes into the Stratosphere but has no forecast data put into it.

Edited December 23, 2012 by johnholmes

[bluearmy]

i think some of you need to 'pinch yourselves'. we are over two thirds through december and returning a below av CET. that is likely to continue to tick upwards and given we look likely to have a cold first half and mildish second half, an av CET seems likely now (high min returns over the next week the main reason we will avoid a cold return overall).

we have avoided a cold snowy spell by a slim margin. we are now in a mobile flow for the foreseeable. yesterday morning, the theme was a mid atlantic block in the mid T200's from gfs/ecm/gem. 24 hours later and that has drained away. it might be back tomorrow? no point in guessing and we go on what the output is consistent on. that is mobile and westerly in general though the current gfs trend is definitely to lift heights in nw europe week 2. that would be a welcome relief.