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Paul

Cold hunt - models and chat

Paul

Please ensure that the majority of your posts in this thread are model related - a theme of model discussion needs to run throughout.
Some off topic chat and reactions are ok, but please use other, more relevant threads for entirely off-topic chat (such as snow reports, met office forecasts and general chat/moans about the weather or this winter).

For more no banter and just model discussion please head to the new focused model thread - this is also a great place to post (or cross post) your longer model summaries or thoughts around the models.

Message added by Paul

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1 minute ago, Broadmayne blizzard said:

Why would anyone expect the NAO to be anything other than positive a lot of the time. All that means is that it is reflecting our climatology. Namely mainly a west to east Atlantic driven pattern operating at various intensities for much of the time. 

As others have said the NAO is not in itself a driver. More it reflects the pattern that other atmospheric drivers create.  Hence if the MJO goes through phases 7-8-1 at high amplitude and takes a month to do so then that month would most likely have a negative NAO recorded as a result of those MJO phases promoting blocking in the North/northeast Atlantic.

It is the baseline, where expectations should be before we look at variables. We are therefore in a period of low expectations and I would argue that is important for anyone forecasting our Winters.

It is a reflection of the sum total of those "drivers" so it is a valuable index. We can conclude from these stats that even with the MJO sometimes being helpful, the longterm trend is for +NAO, which for the UK means it is hard to get a cold spell without triggers like an SSW.

 

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48 minutes ago, IDO said:

It is the baseline, where expectations should be before we look at variables. We are therefore in a period of low expectations and I would argue that is important for anyone forecasting our Winters.

It is a reflection of the sum total of those "drivers" so it is a valuable index. We can conclude from these stats that even with the MJO sometimes being helpful, the longterm trend is for +NAO, which for the UK means it is hard to get a cold spell without triggers like an SSW.

 

The reason we hunt for cold is because it's not that common, and never really has been unless your a rose tinted glasses type of guy.

Decembers NAO value has little bearing on February's. It was a pointless addition to a post that basically said climate norms are climate norms

Had the GFS06z Run arched back with the Jet a bit more the final third of the run would have been cold. a perfectly reasonable outcome from the starting point. The NAO on the run is that that easily defined either. 

Edited by frosty ground

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Could this be the death knell, for this year's cold and snow?

image.thumb.png.390e30ec3923cb1599c64d64a8d87321.pngimage.thumb.png.acecce080ac4e57f67c69afbdb83fbaa.png  

I've a feeling that southern Europe will warm up very fast, come Spring... image.thumb.png.350beca7d2674d8cd1e446e2f2b50ecd.png

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32 minutes ago, feb1991blizzard said:

Yes thoroughly accurate don't you think?

 

Do we have signs of a split with the Siberian vortex allowing cold to filter

image.thumb.png.de944d7e97429aefcfb6adec7602bba9.png

Edited by winterof79

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2 minutes ago, winterof79 said:

Yes thoroughly accurate don't you think?

No, but they tied in with a lot of the cold ramping that went on in here which people find acceptable but moan when people post mild charts.

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20 minutes ago, feb1991blizzard said:

No, but they tied in with a lot of the cold ramping that went on in here which people find acceptable but moan when people post mild charts.

What with it being the hunt for cold thread an’ all..... 

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On 19/01/2019 at 21:42, Paul said:

In this thread, please feel free to discuss the model output with a cold slant, but should other weather types be showing in the output, discussing those is fine too.

You should read the original post so!

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Just now, Day_10 said:

What with it being the hunt for cold thread an’ all..... 

Yes but its the hunt for cold thread, there is nothing wrong with saying you are gutted because non is in the offing, agree that posting warm south westerlies and then putting:yahoo:afterwards is not for this thread but i don't see the point in lying.

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22 minutes ago, feb1991blizzard said:

Yes but its the hunt for cold thread, there is nothing wrong with saying you are gutted because non is in the offing, agree that posting warm south westerlies and then puttingafterwards is not for this thread but i don't see the point in lying.

Agree to a point Feb, but there are some pointing out now that there are no background signals to bring a cold spell!! Pretty sure a good many have been banging on about the great background signals that would bring us one hell of a cold spell!! So when the signals are there, it doesn't deliver, and when the signals are know longer there, that also fails to deliver, bloody hell doesn't leave us with much to go on does it 😉 perhaps next year we should rename this thread. 

THE HUNT FOR THE PERFCT BACKGROUND SIGNALS

Edited by Mattwolves

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Amusing how GFS 06z goes from this

image.thumb.png.b76def960c7bbe34fc2e656871450145.pngimage.thumb.png.9108bf206799b4a9915c2c0ce99e5216.png

to this

image.thumb.png.cfa11c0b37e92a4730d923e97c32041e.pngimage.thumb.png.421e264d5f859dcd381e129a63fe1d91.png

The Greeks have it again

😁

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Morning, a few people discussing the NAO I see. Thought I'd clear up this argument.

First there are different definitions of the NAO, each with varying levels of relevance to our shores. The most relevant I think is the SLP gradient from Gibraltar to Reykjavik which goes all the way back to 1821. I thought I'd look at the correlations between the NAO for one month and the following others. Here is what I found.

image.thumb.png.1ed914fc482da6cef878041bc5786696.png

So any relationship between the NAO from 1 month to another following winter month is weak at best. There appears to be some correlation between November and December NAO but it is not statistically significant and the same can be said about February and March.

However there is a strong correlation between North Sea SSTs from one month to the next (much stronger then other times of the year) and low SLP can be persistent in the far NW Atlantic during late winter and spring if the January NAO is positive.

Back to the model output and the swingometers for February 20th and the models were firming up on a milder picture persisting until the 20th. The 06z was a little more varied but nothing much in the way of cold. No charts of note really for this time period to post (if its cold you are after).

 image.thumb.png.74ce47cc2054822ac87f42f6556da702.png

By February 25th a very mild picture, the swingometers are a Sarri sight indeed, like watching your football team lose 6-0 if its mild you are after. Still a long way out but the prospects of this winter are rapidly falling it seems. The 00z parallel is our only hope 😞 

image.thumb.png.1da605a004dff569a406dbcb151b0949.png image.thumb.png.f61d4a105ab23f65484f232e97fb53c3.png

The global temperature anomalies show that our best hope of getting some decent cold is a block to our north given our east is so mild. The western side of North America is hogging the cold again...

image.thumb.png.fef6a664f4d10014ed41278204ce4e40.png

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1 hour ago, Ed Stone said:

Could this be the death knell, for this year's cold and snow?

image.thumb.png.390e30ec3923cb1599c64d64a8d87321.pngimage.thumb.png.acecce080ac4e57f67c69afbdb83fbaa.png  

I've a feeling that southern Europe will warm up very fast, come Spring... image.thumb.png.350beca7d2674d8cd1e446e2f2b50ecd.png

oh look there goes winter of to Greece again !

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2 hours ago, Summer Sun said:

I was looking at the daily records not that long ago maybe Saturday could be the best chance?

f0f2d4e7-077d-46a8-859f-c92216d0b1f0.thumb.png.2bff4ba9ee038a991d7b5f3c46f6c720.png

 

I fail to see how temperature records could be broken, with average temps ranging from 8-11 degrees throughout the week! 

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1 minute ago, Mattwolves said:

I fail to see how temperature records could be broken, with average temps ranging from 8-11 degrees throughout the week! 

Chance of an isolated 15c later in the week subject to cloud cover it's certainly unlikely we'll see daily records go but maybe an outside chance on Saturday

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26 minutes ago, Summer Sun said:

Chance of an isolated 15c later in the week subject to cloud cover it's certainly unlikely we'll see daily records go but maybe an outside chance on Saturday

where are you getting that from

132-582UK.GIF?11-6

 

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2 minutes ago, frosty ground said:

Sorry for a second i thought it was model discussion but i assume its not quite showing on any model just yet then

The ECM D6-D10 anomalous warmth:

 

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Well, at least the background signals are still looking ppppotentially good as we go into early spring!👍😃

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20 minutes ago, frosty ground said:

where are you getting that from

132-582UK.GIF?11-6

 

I think the Fohn effect might have something to say about that?

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54 minutes ago, Summer Sun said:

Chance of an isolated 15c later in the week subject to cloud cover it's certainly unlikely we'll see daily records go but maybe an outside chance on Saturday

Aye, Fohn effect, could be higher in prone spots, N Wales/E Scotland, only expecting 13 or so here

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10 minutes ago, IDO said:

The ECM D6-D10 anomalous warmth:

 

Temperatures are going to be above average maybe 3 degrees above average. according to that chart

Max average in Feb is 6.6 not sure that equates to 15.

And again i asked which model showed 15 and as it stand there isn't one. (which is not saying there won't be either)

 

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18 minutes ago, IDO said:

The ECM D6-D10 anomalous warmth:

 

Two words for that chart from a coldies perspective.  Absolutely horrifying!

Edited by Don

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4 minutes ago, frosty ground said:

Temperatures are going to be above average maybe 3 degrees above average. according to that chart

Max average in Feb is 6.6 not sure that equates to 15.

And again i asked which model showed 15 and as it stand there isn't one. (which is not saying there won't be either)
 

That's a four-day mean, it's not a daily forecast...

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6 minutes ago, Don said:

Two words for that chart from a coldies perspective.  Absolutely horrifying!

I'm pretty sure folk suffer with SAD through the winter and start to feel better come spring, hell, its having the opposite effect on me, think I'm gonna need medication to get me through these next few months 😜

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