Model output discussion - mid January

[Decemberof2010]

Not a surprise though is it? The GEFS can quite often throw out a few stonking runs and completely drop the signal. Back in December the NH was crazy on over 15 perts. Stayed that way for about 3 days then died a death. 

[Daniel*]

7 minutes ago, feb1991blizzard said:

Disagree, once you get the critical point coming into the 240 range  and you start to see less and less with each run, you know the writing is on the wall, not saying we wont see them jumping off a cliff at 384 in the next few days but that's the next chance, 2 days ago we were getting 7 or 8 flatliners with frigid temps and a good few more looking like they would if they went further, one suite had about 15 out of 20 stonkingly good NH setups, that's gone down consistently in the last 4 runs.

It’s got nowhere near that though?

Only yesterday 06z actually GEFS reached the cold ‘pinnacle’ still interest is apparent it’s not been wiped off.

 

[feb1991blizzard]

Incidentally the GEM ens have been consistently much flatter than GEFS the last few runs.

[feb1991blizzard]

Just now, Daniel* said:

It’s got nowhere near that though?

Only yesterday 06z actually GEFS reached the cold ‘pinnacle’ still interest is apparent it’s not been wiped off.

 

Yes but you can see if you go through the individual members and the mean where its slowly heading, basically there needs to be a sudden turnaround in the next 24 hours, they have never been backed by any other ensemble suite either.

[Daniel*]

12 minutes ago, Decemberof2010 said:

Not a surprise though is it? The GEFS can quite often throw out a few stonking runs and completely drop the signal. Back in December the NH was crazy on over 15 perts. Stayed that way for about 3 days then died a death. 

Yes there tends to be 1 or two that tease, I had a look through I tend to only save in graph form them when they’re decent and nothing stands out in December - so not quite true. Certainly nothing as striking as yesterday.

[ACCOUNT DELETED]

GFS 12z shows a much better weekend to come in the southwest compared to last weekend's wet Saturday followed by heavy rain and flooding on Sunday as high pressure has more of an influence here

Edited January 23, 2018 by Draig Goch

[Decemberof2010]

13 minutes ago, Daniel* said:

Yes there tends to be 1 or two that tease, I had a look through I tend to only save in graph form them when they’re decent and nothing stands out in December - so not quite true. Certainly nothing as striking as yesterday.

Ok well there was definitely some great charts looking from a NH view only. Granted I don't look in graph form but the images at least looked great:-)

[Daniel*]

2 minutes ago, Decemberof2010 said:

Ok well there was definitely some great charts looking from a NH view only. Granted I don't look in graph form but the images at least looked great:-)

I think there was a lot of very good NH profiles but with them a lack of cold air available yesterday had both.  

[feb1991blizzard]

Looks like a pattern being converged on definitely now - I'm afraid its all aboard the circular high out west that cant get far enough North train!

[igloo]

1 minute ago, feb1991blizzard said:

Looks like a pattern being converged on definitely now - I'm afraid its all aboard the circular high out west that cant get far enough North train!

Yes it has been the pattern all season this type of setup just one of these years i guess but the usual suspects have done well from these myself included nothing long lasting on these setups of course it just topples over after a 2-3 days but better than nothing the days of greenland and scandi HP Are all but over nowadays but some people will not accept reality unfortunately 

[feb1991blizzard]

2 minutes ago, igloo said:

Yes it has been the pattern all season this type of setup just one of these years i guess but the usual suspects have done well from these myself included nothing long lasting on these setups of course it just topples over after a 2-3 days but better than nothing the days of greenland and scandi HP Are all but over nowadays but some people will not accept reality unfortunately 

Disagree with this, its just because we have been in the middle of a solar cycle, everyone was saying the same thing in about 2007 as well, I will still look for the teleconnective signals and FI model output firmly believing one still can happen, the only difference with me, I accept the fait when we have a failure a long time before others do, you wont ever get me claiming that the models will flip back inside 96 when an E'ly has been dropped from 144 to 120 and every single ens member of 2 suites and every professional forecaster suggests the contrary.

[nick sussex]

Change is coming!

Give it a few days as the MJO does look like bringing a change upstream.

Central USA troughing If it verifies is likely to deliver Euro troughing downstream.

The bit in the middle is the likely more uncertain aspect, a flow from the ne can’t be ruled out.

 

[Stuie]

Nick, are we still proposing an Arctic high to aid this development?

[nick sussex]

Latest MJO update from the Global Tropics  Hazards Outlook:

The MJO remains coherent, with both the RMM-based and CPC velocity potential based MJO indices depicting robust amplitude and eastward propagation. The enhanced convective phase of the MJO is over the Maritime Continent, constructively interfering with the La Nina base state. A large envelope of enhanced trade winds persists over the western and central Pacific, with westerly anomalies extending from the Indian Ocean to Borneo. The upper-level velocity potential anomalies continue to reflect a coherent Wave-1 pattern, with the anomalous upper-level divergence in phase with negative OLR anomalies over the Maritime Continent. Dynamical and statistical model RMM-index forecasts consistently depict a continuation of robust MJO activity over the next several weeks, with the enhanced convective phase propagating over the West Pacific by Week-2. The ECMWF depicts a slightly faster propagation of the signal, and the 30-day ECMWF run maintains an amplified signal over the East Pacific and Western Hemisphere through Weeks 3 and 4. Based on these observations and forecasts, the MJO is anticipated to play a large role in the evolution of the global tropical convective pattern, and will likely continue to influence the midlatitude response. This MJO event has teleconnected well with the North American longwave pattern, and has contributed to the warming trend across the central and eastern CONUS. A West Pacific MJO event would potentially support a pattern change during early to mid-Feburary, with increased ridging over western North America, and downstream troughing over eastern Canada and the U.S.

The above certainly indicates the MJO will play a role and won't be muted out by La Nina.

So if that verifies its inevitable that we will see changes downstream in Europe.

Lets hope we get some luck with a Euro trough and high pressure developing to the n or ne.

The correlation with a central US or eastern trough normally is that Euro trough, the amplification of that US troughing will determine the behaviour of the jet stream downstream so we're looking for that cut back sw to develop some higher pressure to the north or ne.

Any blocking doesn't have to be super strength! just enough to keep splitting the jet to the west of the UK with energy heading se to feed the Euro trough and the some splitting ne, its always a juggling act in these situations.

For this reason and given the MJO is on the move bear that in mind with the outputs which are likely to be a bit more volatile than normal.

Theres a bit more hope for coldies lets hope we can get something out of this likely shuffling of the NH pattern.
 

Edited January 23, 2018 by nick sussex

[shotski]

ECM extended EPS has a rather strong anomaly for a mid Atlantic ridge and low heights into Europe. And as I’m off skiing on the 8th Feb it’s all good ??

[mulzy]

Extended eps continues to show troughing over Europe (actually slightly more widespread than this morning's run) - GEFS currently does not show this signal.  Will it be a case of the GEFS catching up again I wonder?

The worry from a coldie's perspective is the lowish heights over Greenland.

 

Edited January 23, 2018 by mulzy

[Sneachtastorm]

16 minutes ago, nick sussex said:

Latest MJO update from the Global Tropics  Hazards Outlook:

The MJO remains coherent, with both the RMM-based and CPC velocity potential based MJO indices depicting robust amplitude and eastward propagation. The enhanced convective phase of the MJO is over the Maritime Continent, constructively interfering with the La Nina base state. A large envelope of enhanced trade winds persists over the western and central Pacific, with westerly anomalies extending from the Indian Ocean to Borneo. The upper-level velocity potential anomalies continue to reflect a coherent Wave-1 pattern, with the anomalous upper-level divergence in phase with negative OLR anomalies over the Maritime Continent. Dynamical and statistical model RMM-index forecasts consistently depict a continuation of robust MJO activity over the next several weeks, with the enhanced convective phase propagating over the West Pacific by Week-2. The ECMWF depicts a slightly faster propagation of the signal, and the 30-day ECMWF run maintains an amplified signal over the East Pacific and Western Hemisphere through Weeks 3 and 4. Based on these observations and forecasts, the MJO is anticipated to play a large role in the evolution of the global tropical convective pattern, and will likely continue to influence the midlatitude response. This MJO event has teleconnected well with the North American longwave pattern, and has contributed to the warming trend across the central and eastern CONUS. A West Pacific MJO event would potentially support a pattern change during early to mid-Feburary, with increased ridging over western North America, and downstream troughing over eastern Canada and the U.S.

The above certainly indicates the MJO will play a role and won't be muted out by La Nina.

So if that verifies its inevitable that we will see changes downstream in Europe.

Lets hope we get some luck with a Euro trough and high pressure developing to the n or ne.

The correlation with a central US or eastern trough normally is that Euro trough, the amplification of that US troughing will determine the behaviour of the jet stream downstream so we're looking for that cut back sw to develop some higher pressure to the north or ne.

Any blocking doesn't have to be super strength! just enough to keep splitting the jet to the west of the UK with energy heading se to feed the Euro trough and the some splitting ne, its always a juggling act in these situations.

For this reason and given the MJO is on the move bear that in mind with the outputs which are likely to be a bit more volatile than normal.

Theres a bit more hope for coldies lets hope we can get something out of this likely shuffling of the NH pattern.
 

High pressure to the NW would also do. A Greenland high

[feb1991blizzard]

This would be my closest match as to what will verify, either this or a high over the top of us.

[CK1981]

11 minutes ago, feb1991blizzard said:

This would be my closest match as to what will verify, either this or a high over the top of us.

I imagine a high in that position would drag a lot of cloud into the circulation off the Atlantic, so it would be dull and relatively mild for the majority. 

Edited January 23, 2018 by CK1981

[ICE COLD]

12 hours ago, SN0WM4N said:

You said yourself that easterlies in la la land never make it. I know the charts look different but it remains the same. The model picked up the low g wave pattern then as it counted down to t0 it changed. A classic reverse case is that of Feb 2009 they had PM airflow in the extended range and by T0 easterly. 

The weather chooses but let me ask you this would you rather see zonal mess in FI or easterlies popping up here and there in FI? 

Ok fair enough SNOWM4N . I've only been model watching since December 2013 and I have never seen a proper national cold spell count down to T0 it always seems to get watered down it's so frustrating. And yes would rather not see zonal in the models much prefer easterlies and northerlys . But I would prefer it more if it got down to t0 with -12 850s over us and a blizzard ?

[snowbunting]

3 hours ago, Ed Stone said:

I remember that one, too...Wasn't it 18C, in Banchory, only a day or two before?

It was yes... that was a classic Nly for Highlands and Islands. 

[ArHu3]

13 hours ago, SN0WM4N said:

You said yourself that easterlies in la la land never make it. I know the charts look different but it remains the same. The model picked up the low g wave pattern then as it counted down to t0 it changed. A classic reverse case is that of Feb 2009 they had PM airflow in the extended range and by T0 easterly. 

The weather chooses but let me ask you this would you rather see zonal mess in FI or easterlies popping up here and there in FI? 

From the easterlies I have looked up re-analysis and if possible model history they seem to come into existence from pretty much zonal conditions but the highs in the Atlantic are usually more pronounced and might have some green depressions/"bubbles"  near tropic of cancer, oh and a big huge high pressure of the pacific coast  of the US

 

https://www.meteociel.com/modeles/archives/archives.php?day=1&month=2&year=1985&hour=0&type=ncep&map=5&type=ncep&region=&mode=0

 

We see this pattern many times during winter btw, it usually fails but most successful easterlies saw similar patterns 

Edited January 23, 2018 by ArHu3

[chionomaniac]

2 hours ago, igloo said:

Yes it has been the pattern all season this type of setup just one of these years i guess but the usual suspects have done well from these myself included nothing long lasting on these setups of course it just topples over after a 2-3 days but better than nothing the days of greenland and scandi HP Are all but over nowadays but some people will not accept reality unfortunately 

Anyone who is a long standing member on this site will remember this tosh being stated in the late noughties time and time again.... However it is not that HLB's favourable for the UK are over, moreso that the conditions haven't aligned to provide them for a while. This year we are battling low GLAAM, and any strat or trop atmospheric response will have to overcome this. With low solar conditions coming for the next few years, there will certainly be chances. Traditionally, La Nina febs don't produce cold for us here, but we still would be foolish to write anything off with the MJO forecasts battling against the low GLAAM and the strat becoming more conducive to a possible SSW. That is the real reality.

 

[ANYWEATHER]

28 minutes ago, ICE COLD said:

Ok fair enough SNOWM4N . I've only been model watching since December 2013 and I have never seen a proper national cold spell count down to T0 it always seems to get watered down it's so frustrating. And yes would rather not see zonal in the models much prefer easterlies and northerlys . But I would prefer it more if it got down to t0 with -12 850s over us and a blizzard ?

2010 was the last full coverage of snow....And Gfs as come around to the ecm....

[blizzard81]

Another cold, snowy ecm control run for debilt. I wonder when one of these will verify? I also wonder how close it is to the op?

Edited January 23, 2018 by blizzard81