Winter Model Discussion - Cold Hunting -12Z 03/01/13

[MKN]

Is the red line not what has already happened? Already underway.

Yes but you cant guarentee that come next week it will have continued and if it hasn't the model ouput could look very different.

[BLAST FROM THE PAST]

FI, espically for me, is very decent, from 204 on wards under sub zero uppers! 324 looks very promising although GH rather than SH.

Yes the solution is likely to move onto a Greenland HP as we go forward. The chart [which I can't post at work] for 19th January is immense. Heavy snow for NE and East and intense cold to boot

BFTP

Edited January 5, 2013 by BLAST FROM THE PAST

[snowking]

I knew someone would mention the stratosphere. Warming there that's set to occur are still forecasted warmings. So if the forecast for that to happen is wrong then the implications to our weather towards a colder outlook may not happen. People always seem to think stratospheric warming and AO Nao and all the other teleconections GP talks about are guarenteed. They are still all forecasts. And as with the weather forecasts they don't always occur

ST I would recommend actually going over to the very informative stratospheric thread and reading through the information - you would find that the stratospheric warming is taking place NOW, with the zonal wind reversal TOMORROW. Accrington Stanley have more chance of winning the FA cup than the SSW has chance of not verifying.

As for the outputs today so far, they are all very much following the stratospheric lead now, with ridges heading north of the UK and initially to the NE, with the whole longwave pattern retrogressing over time, pushing heights towards Greenland.

SK

[Jason H]

Yes but you cant guarentee that come next week it will have continued and if it hasn't the model ouput could look very different.

Who's saying they can guarantee it will continue? People are forecasting it to continue? What's your point?

[swfc]

I think im missing something ?Is the pv not obliterated on this run and altho its in"fi"the northern hemisphere set up is incredible.Why are some people being down beat.the 500mb charts also tie in along with the nao?

[Ice Day]

Of course all the usual 'cautions' apply, but this would do very nicely for pretty much the whole of UK and Ireland (the frames up to 384 are even better!!!)

[nick sussex]

Yes but you cant guarentee that come next week it will have continued and if it hasn't the model ouput could look very different.

You need a second warming to reinforce the first which is still forecast to occur. The strat forecasts are less volatile than the normal slp charts you see. Recretos did some very good research showing that a strat forecast at around 360hrs is similar in correlation to the model outputs at day 6 .

Of course I can understand people always expect things to go pearshaped especially given recent history but you know they do sometimes go right!

[Dexter29]

Hi, I've noticed that the Temp in Toronto ON, has been around -7 to -15 over the last couple of weeks, rapid warm up happening there, by Wednesday up to +3 and rain. Is this of importance? I'm sure I've heard a warm up in the East America has preceded cold on our shores in winters past.

Cheers

Karl

06z pushes things into deep FI once more. As pros and members have reiterated on here, it means nothing.

@karlos83 I believe NYC reached 21c in Feb 1991 while London was buried in over a foot of snow.

[EML Network]

And so finally this morning we can see how the pieces of the jigsaw are beginning to fall into place.

at + 192 the ECM and the GFS are not a million miles apart, with High pressure egg shaping and centering somewhere over Ireland, what happens thereafter will be open to a lot of variation.

In my opinion this is the first bite at the cherry and as ever rely's on things being in the sweet spot, if some of us are to get some snow.

Move that High pressure system any further East and the cold air stays out of reach to the East with it, move it West and more of us will have fun, it's all too close and we have been here many times before, especially when you have an Azores High lurking and ready to spoil the party before it's even begun.

the ECM itself highlights this perfectly...here it is at + 192, just West enough to give the East a taste of cold and potential for a few flakes, but notice the Azores High.

Corresponding 850's

Now at + 240 and as you can see the High has linked up with the Azores, has grown in size and because of this the cold air is forced under the block, how many times have we seen this sort of pattern develop...only for the cold air to sink underneath the UK ?? in this type of set up it's the South and East that stand the best change of getting lucky (for once)

corresponding 850 's

[johnholmes]

I knew someone would mention the stratosphere. Warming there that's set to occur are still forecasted warmings. So if the forecast for that to happen is wrong then the implications to our weather towards a colder outlook may not happen. People always seem to think stratospheric warming and AO Nao and all the other teleconections GP talks about are guarenteed. They are still all forecasts. And as with the weather forecasts they don't always occur

On a very amateur level a warming has already occurred, the 30mb spike on 23 December, this gives a predicted block pattern 15-25 days later=7-17 January?

This is now being confirmed is the term I would use by the 500mb anomaly charts over the past 3-4 days.

When the deep cold failed to appear in December the 500mb charts as I tried to show after the event did actually give some warning of this happening as they went into a mobile westerly set up. I failed to see that until after the event so I am pretty confident this time round UNLESS over the next 2-3 days they again begin to back off.

The other difference between the two predictions is where the block is going to start from=north not east.

Edited January 5, 2013 by johnholmes

[chris55]

One positive about the upcoming potential cold spell is that the initial cool down, being bought about by high pressure building in our vicinity, is quite a quick response to the strat warmings. The initial pattern changes could lead to a nice easterly but as things stand a generally colder and dryer period looks more likely, with some frost etc, it's the continuation of the blocked pattern and the trends for pressure rises continuing to our north and north west that is very positive. It shouldn't be a case of an Atlantic breakdown, but a generally more favourable pattern as we head through Jan.

[winterof63]

Hello everyone.

New to Netweather although I have followed the discussions on here for quite a while. I find the informative posts on here really interesting and hope to learn from you guys over time.

Self confessed bias towards preferring cold weather, but to be honest a general fascination with all types of weather. In my opinion we should consider ourselves very fortunate to live in such a varied climate. That's what makes the model watching so fascinating.

Can anyone suggest a good link for me to a site that provides all the model updates.

Thanks.

[Methuselah]

I knew someone would mention the stratosphere. Warming there that's set to occur are still forecasted warmings. So if the forecast for that to happen is wrong then the implications to our weather towards a colder outlook may not happen. People always seem to think stratospheric warming and AO Nao and all the other teleconections GP talks about are guarenteed. They are still all forecasts. And as with the weather forecasts they don't always occur

And, why not 'mention the stratosphere'?

You are right enough about NAO and AO, however: they are nothing more than indices that are derived from what the synoptic models are predicting...The state of the stratosphere, in contrast, has enormous potential as a forecasting tool; which, IMO, fully justifies the current interest in it...

Anyhoo, back to the models themselves; and it's clear to see that major changes are afoot. But, remember, the 'Northern Hemisphere' does not only include London and the Home Counties...

Hello everyone.

New to Netweather although I have followed the discussions on here for quite a while. I find the informative posts on here really interesting and hope to learn from you guys over time.

Self confessed bias towards preferring cold weather, but to be honest a general fascination with all types of weather. In my opinion we should consider ourselves very fortunate to live in such a varied climate. That's what makes the model watching so fascinating.

Can anyone suggest a good link for me to a site that provides all the model updates.

Thanks.

Hello and welcome to NW...Can you please pop your location into your profile?

Edited January 5, 2013 by Rybris Ponce

[swfc]

Hello everyone.

New to Netweather although I have followed the discussions on here for quite a while. I find the informative posts on here really interesting and hope to learn from you guys over time.

Self confessed bias towards preferring cold weather, but to be honest a general fascination with all types of weather. In my opinion we should consider ourselves very fortunate to live in such a varied climate. That's what makes the model watching so fascinating.

Can anyone suggest a good link for me to a site that provides all the model updates.

Thanks.

Welcome.try metiociel Edited January 5, 2013 by swfc

[johnholmes]

hi winter 1963-suitable name for the coldies on here-welcome.

There is a lot of data available on this site if you have a quick look round with data from all the models. Also have a look in the Guides section to help you with lots of useful stuff in there.

As to other sites well the Wetter site probably has everything you want for all the models and in fairly real time as they come out.

enjoy and may I ask that you put your nearest town in your avatar please-thanks?

helps when we all start reporting snow depths and frosts to know just where you are-helps the enjoyment of everyone too.

[Methuselah]

Yes but you cant guarentee that come next week it will have continued and if it hasn't the model ouput could look very different.

You can't 'guarantee' anything, regarding UK weather, ST (that's why we're all so obsessed with it)...But we can attempt to make the best possible use of the tools we have at our disposal?

[phil nw.]

Some solid looking mean charts for the coming cold pattern at Day 8-the 850hPa`s

Some bitter days to come from later next week according to the 2mtr temps-a big drop coming.

It`s getting closer folks!

[Snowfan50]

The high would need to move north right to let the cold from the east flow into the uk and not spain right? this is what im looking at most.

[Iceaxecrampon]

nice to see that it looks like the 500mb charts and the 30mb spike all gave correct guidance; the 30mb from 23 December and the anomaly charts from about 4 days ago.

Mind you it could still of course go pear shaped!

....strangely enough..

This time last month....

Yes - "experts" predicted something half decent by mid Jan - wont post it but just had a look (and I know I shouldn't) deep in FI

Pink = Good

Ian

[swfc]

The high would need to move north right to let the cold from the east flow into the uk and not spain right? this is what im looking at most.

Can you be a bit clearer?If i understand you then the high would be to be over scan to pull in an easterly

[Ian Brown]

The high would need to move north right to let the cold from the east flow into the uk and not spain right? this is what im looking at most.

Yes, we need a high latitude block to get the cold uppers to the3 UK, as things stand on the 06z for example, we would end up being unlucky with the cold air flooding into Southern Europe whilst we remain under High pressure.

[IDO]

The high would need to move north right to let the cold from the east flow into the uk and not spain right? this is what im looking at most.

High to Greenland and drag the pattern west drawing in the very cold Eastern Euro temps: .

[AWD]

London ens

Temperature:

A cold set of ensemble members there, with the majority trending to 6c or colder. ECM was a colder option, but not unsupported. GFS follows the mean well.

Wind;

Not much to say really, both EC & GFS well supported and a spread as you would expect in FI.

Precipitation;

Slightly wetter than yesterday's, with the GFS taking a wetter route compared to the drier ECM. With these ensembles being a bit wetter & colder than yesterday's, this could suggest that with time, pressure to the north could retrogress's far enough away from the UK, but still keeping the colder air over us, allowing for precipitation to fall, increasing the probability of snowfall.

[Snowfan50]

Yes, we need a high latitude block to get the cold uppers to the3 UK, as things stand on the 06z for example, we would end up being unlucky with the cold air flooding into Southern Europe whilst we remain under High pressure.

Yes this is what i mean, i remember this happening last feb with the exact same thing with the high over us, very frustrating.

[swfc]

All in all pretty good set of runs so far today and trending towards a much more wintry outlook.Great to see the ecm and esp the ukmo on board.Well my culture shock levels have it a ssw level on here slightly this morning so its pub and footie.Enjoy your afternoon