Model Output Discussion 29th December - Into mid-Winter.

[robbo88]

 

 

coldest spell of winter this weekend? From reading in here I wasn't getting that? 

[snowice]

1 minute ago, robbo88 said:

 

 

coldest spell of winter this weekend? From reading in here I wasn't getting that? 

This is what Steve Murr noticed at 120hrs ECM, cold easterly for South East England. 

[Summer Sun]

12 minutes ago, Summer Sun said:

 

 

...and 15d meteograms that run lean (again for now) to rather +ve avg temps developing last week Jan, with most members SW'ly/W'ly

https://twitter.com/fergieweather/status/821458901249982464

 

[Ali1977]

3 minutes ago, Summer Sun said:

...and 15d meteograms that run lean (again for now) to rather +ve avg temps developing last week Jan, with most members SW'ly/W'ly

https://twitter.com/fergieweather/status/821458901249982464

 

My sounds like an ECM wild goose chase again, maybe we'll know more tomorrow 

[winterof79]

On ‎1‎/‎16‎/‎2017 at 17:31, feb1991blizzard said:

The azores high is moving East though, confirmed by the ensembles by about 240, its as flat as a pancake with Westerly winds, I would put my life on a spell of zonality now, and don't see how anyone could possibly deny it.

Gulp..........I hope you are a cat

Edited January 17, 2017 by winterof79

[feb1991blizzard]

Just now, winterof79 said:

Gulp..........I hope you are a cat

Refer you to the above Ian Fergusson post.

[bluearmy]

Interesting that the gfsp 06z tried to build a scandi ridge before giving way to the the Atlantic 

Ext eps  clearly continue with the Atlantic looking strong just to our west  but as with the current MLB, the ECM op could again lead the way with some consistency-  the mean jet not pushing through much past the meridian towards the end of week 2 as high anomolies begin to look stronger to our east. 

Mobility remains favoured beyond mid next week but blocking fighting back already. 

[chris55]

17 minutes ago, robbo88 said:

 

 

coldest spell of winter this weekend? From reading in here I wasn't getting that? 

The continental flow under high pressure has been showing for days now for the weekend, this period was well modelled especially on the GFS, before what looked like the return to a more south west zonal type flow into next week.

 The longer term often takes precedence in this thread if no major obvious cold is showing, which is understandable as we look for the holy grail, but a cold continental flow can bring some very chilly surface temps, though the chance of snow is very low. 

If you take tonight's cold temps in the south east as an example, -6 rural because the continental cold is just clipping the the south east corner. And although this flow will be tempered over the next few days it will start to creep back in later in the week.

[winterof79]

6 minutes ago, feb1991blizzard said:

Refer you to the above Ian Fergusson post.

I much prefer Mr Hammonds. And then a battle rather than an Atlantic onslaught

 

[Day 10]

I'm ready to get back on the roller coaster, are you? (rolls eyes), here we bloody go again...

This time it will count down like clockwork, PROMISE!

[Captain Shortwave]

Another pulse of cold or very cold air eastern parts of Europe is certainly a probability with a strong mid-latitude ridge near the UK.

Day 6 charts

      

Signs of another Scandi trough forming with cold air sharpening and digging south though with varying degrees of success. The ECM being the most amplified but from there you can see the mobile tropospheric vortex move away from our north east which could allow the ridge near the UK to end north eastwards and allow cold air over Western Russia/Eastern Europe back westwards somewhat. Patterns do have a habit of repeating more often than not so I would be surprised if the models tease with another easterly just like the ECM op over the coming days. Again the ingredients are there, it is just whether we have any faith that we could get wintry cold from this. 

One thing I do see is that the mid-latitude high is looking to be more stubborn than initially thought, I don't know how that comes as a surprise given how our winter has gone so far.

 

[winterof79]

Interesting cluster going colder early on but in the extended the Control hits the bottle hard

[feb1991blizzard]

4 minutes ago, winterof79 said:

I much prefer Mr Hammonds. And then a battle rather than an Atlantic onslaught

 

So do I in terms of what I would prefer, but that solution a) would bring dry but very cold weather. b) is unlikely to happen based on all the data, what does look promising is the strat, we need to see some propagation downwards in the next few days though, I definitely think sometime in feb, there will be a southerly tracking jet, when, and what form it takes are both questions to be resolved.

[winterof79]

1 minute ago, feb1991blizzard said:

So do I in terms of what I would prefer, but that solution a) would bring dry but very cold weather. b) is unlikely to happen based on all the data, what does look promising is the strat, we need to see some propagation downwards in the next few days though, I definitely think sometime in feb, there will be a southerly tracking jet, when, and what form it takes are both questions to be resolved.

Yes all tongue in cheek feb, just a matter of time really. Nice to see the continental flow make a fist of it for a while.

[Seasonality]

41 minutes ago, robbo88 said:

 

 

coldest spell of winter this weekend? From reading in here I wasn't getting that? 

Why does he talk about a "charmed life." The south isn't suffering blizzards or an extreme freeze or a hurricane etc. Funny how some presenters like to exaggerate, like describing 7°C in January as a cold day. No disrespect to Mr Hammond, I suspect it is all part and parcel of entertaining as you inform.

[winterof79]

1 minute ago, Seasonality said:

Why does he talk about a "charmed life." The south isn't suffering blizzards or an extreme freeze or a hurricane etc. Funny how some presenters like to exaggerate, like describing 7°C in January as a cold day. No disrespect to Mr Hammond, I suspect it is all part and parcel of entertaining as you inform.

It will be just put the big coat on for us Norverners

[Singularity]

22 minutes ago, bluearmy said:

Interesting that the gfsp 06z tried to build a scandi ridge before giving way to the the Atlantic 

Ext eps  clearly continue with the Atlantic looking strong just to our west  but as with the current MLB, the ECM op could again lead the way with some consistency-  the mean jet not pushing through much past the meridian towards the end of week 2 as high anomolies begin to look stronger to our east. 

Mobility remains favoured beyond mid next week but blocking fighting back already. 

This winter more than many seems to have a habit of causing entire model suites to assume one thing only for something else to turn out to be the way forward, though it has mostly been outside of the 10-day range which makes this occasion seem more unusual - that is, if the greater ridge influence with cold air held in-situ or fed in from the east does come to pass... if only such a strong trend meant we could be more certain that it won't flip the other way again 

Just having the ridge hold steady would raise interesting questions regarding how (poorly, it appears) the models have handled the balance between phase 8 and phase 1 type MJO forcing in the mid-range. I've read that forcing from this region has a real tendency to bring about some of the greatest model inconsistencies.

[Singularity]

Looking more closely to see how 'circumstantial' the ECM 12z is i.e. how much does it rely on a low behaving just-so, and there's a very interesting point at day 7 because you have the main Atlantic trough orientated well for driving WAA north of Scandinavia and build a ridge there - this alignment with such extension of the trough south aided by the Canadian ridge driving a plunge of cold air down west of the Azores days 6-7 - but there's also what could be a 'spoiler' low just NE of Iceland.

  

This particular run manages to turn that potential spoiler into an aid as it splits from the main Atlantic jet and slides southeast through W. Scandinavia, placing it where it can both support a ridge at a higher latitude and help move cold air west through Europe from Asia.

Based on the way these type of situations have tended to go in recent months, there's every chance this low will fail to split away and slide in this manner, in which case the cold air would not make such good progress east even if there's a strong build of pressure through Scandinavia. This week being a good case in point.

In any case, the low is a bit far east for us anyway - we're left looking for further trough disruption to the west with a classic slider low that moves for Central Europe.

 

So to conclude, it looks to be that the build of pressure across Scandinavia is dependent on the upstream trough stretching out a good way south in the 6-7 day range, making it fairly circumstantial but not too much thanks to the Canadian ridge already being well developed event at just 5 days range and with some support from GFS, while the advection west of cold air to such an extent is highly circumstantial and so not to be taken at all seriously at such range - which is the normal practice anyway, but I though it'd be nice to explain why in a scientific manner, because that's just what I'm like I'm afraid  

Now I should really stop posting things as I'm in a dual with one of those meddling winter bugs, and not the creepy-crawly kind! 

[Purga]

Looking pretty chilly for most on Sunday if GFS 18z is to believed.

Good easterly flow off a cold continent

Dry cold with low DPs

Clear skies

Brrrr....

If it does go mild so be it but there looks like some cold for us to enjoy in the shorter term.

Maybe not snowy but who knows what surprises may crop up once the cold is in place??

[damianslaw]

The theme of mid lattitude blocking holding back the atlantic has held sway preety much since July, and indeed I see this theme continuing through the rest of the month, any atlantic attempts to kick it aside being rather futile, and a glancing blow, with the jet having little oomph to it, aided by the lack of cold air spilling out from the eastern USA seaboard - certainly no explosive cyclogensis heading our way, all making for a very stubborn sluggish pattern, with proper cold tantalisingly close to our shores but never making sufficient inroads.

It needs a major shake up, to change things it seems, just rinse and repeat otherwise.

ECM once again playing around with height rises over scandinavia, and most likely will continue to do so, but always beyond the reliable timeframe.

How long will this pattern hold sway... who knows, interesting to see how the strat behaves over the coming 2 weeks, may aid a major shift away from mid lattitude blocking dominating, but will it aid northern blocking, or a more sustained mobile flow.. where will the jet head too..

Despite it being a very frustrating winter so far yet again for anyone wanting some sustained cold snowy weather, it is one though that continues to show many possibilities - with equal chance of atlantic weather not ruling the roost, something that hasn't been the case past 3 winters. Might end up being one of those seasons when the most sustained cold below average conditions occur outside of the core winter months, i.e. Nov and March, just like 2005/2006 for instance, we could end up with a 2004/2005 on our cards as well, after a winter devoid of anything particularly cold and snowy, we had a 4 week easterly dominated spell mid Feb that came out of nowhere.. we shall see.

Edited January 17, 2017 by damianslaw

[TEITS]

Well that ECM has put the cat amongst the pigeons. As I said this morning I noticed a trend from the models backing away from mild, unsettled, zonal. However even im surprised at the 12Z ECM.

Just check the 12Z ECM on Sunday for 25th Jan.

Todays!!

At the rate this is going I would not be surprised to see a massive flip in the models with a colder E/NE,ly develop earlier than +240.

[blizzard81]

4 minutes ago, TEITS said:

Well that ECM has put the cat amongst the pigeons. As I said this morning I noticed a trend from the models backing away from mild, unsettled, zonal. However even im surprised at the 12Z ECM.

Just check the 12Z ECM on Sunday for 25th Jan.

Todays!!

At the rate this is going I would not be surprised to see a massive flip in the models with a colder E/NE,ly develop earlier than +240.

Would you still prefer the zonal option now?

[The Enforcer]

1 hour ago, Ali1977 said:

My sounds like an ECM wild goose chase again, maybe we'll know more tomorrow 

It will likely keep chasing until around T+120. That said, the cold upper air isn't even here by T+240 and it already looks destined for Central Europe. It would be a nice change if it was nudged in the uk's direction at the eleventh hour.

Well before any easterly, the high pressure is starting to look more powerful than 'winterisoverman' could possibly have imagined.

[Snowman.]

GFS actually taking steps towards the ECM solution but still flatter and further east it separates the low north sending less energy NE and keeps some back.

It's shown well in the jet stream forecast

Strong on a SW/NE axis 

not as strong on the 18z with a curl back up by iceland. 

wont stop the atlantic onslaught but its a slowdown. 

Edited January 17, 2017 by SN0WM4N

[blizzard81]

Good old gfs predictably sticking to it's guns - for now!