Model output discussion - heading into 2018

[Duane S.]

 

ECM D10 interesting and I'm not so sure the Atlantic just piles in thereafter. The -EPO and vortex tilt not quite as favourable as the 12z D10 on the face of it perhaps. But should the Pacific ridge intensify or at least not retract too quickly from here, that Norwegian pressure cells looks odds on to get bolstered.

With lower heights below, this is going to be the one to watch

 

[bluearmy]

8 hours ago, feb1991blizzard said:

Agreed but I would have thought you would be the last person to flag this up until at the very very least 12z tomorrow if it was still showing.  I know your views on FI op runs!!

when the op T2 is consistently against the mean and clusters days 9/10 then invariably the eps play catch up. This mornings op run pretty well  removes any concerns. 

the 00z gem day 10 looks like the eps spread from yesterday

this balloon of heights thrown up will be played around with for a few runs I think and how the following pulse of the northern arm interacts with it is going to take a while to resolve. 

[knocker]

Nothing in the ext EPS mean anomalies to suggest any significant variation from a continuation of unsettled weather with the usual caveats. Still the Canadian vortex and the negatively tilted Iceland trough the main players thus a strong westerly upper flow across the Atlantic. This may weaken and split at the eastern end of the Atlantic as there is some ridging into the eastern Arctic and lower pressure in south east Europe.

[Ali1977]

A potential HP setting up near or around Scandy in a few weeks would go against all drivers and the METO long range, so with this in mind I'll say it's prob best just to hope for PM shots. IF a HP does set up to our North I wonder what would be said as to why this happened and what went wrong with the current forecast - it would once again prove any long range forecast for the UK is really just a best guess - I hope it does happen of course. 

[feb1991blizzard]

EPS mean squeezing the vortex with 2 wave pattern (E pacific and Scrussian ridges) with UK although still in a broad WNW mean flow, below average temps right through the extended period, I would have thought theres some cross polar flows in amongst that suite.

EDIT : more westerly actually but still below average.

Edited December 28, 2017 by feb1991blizzard

[shotski]

22 minutes ago, Ali1977 said:

A potential HP setting up near or around Scandy in a few weeks would go against all drivers and the METO long range, so with this in mind I'll say it's prob best just to hope for PM shots. IF a HP does set up to our North I wonder what would be said as to why this happened and what went wrong with the current forecast - it would once again prove any long range forecast for the UK is really just a best guess - I hope it does happen of course. 

Of course a certain poster, who doesn’t seem to post in here much, did call a very cold spell mid Jan in his winter forecast. If you haven’t already seen the forecast, take a look, as it’s a great read. To be honest I’m not sure where to find it now. @iapennell

[Nick F]

The 00z EPS control shows big amplification NE to the west and north of the UK days 9-10 - which then leads to a Scandi high by day 12, but unless if forms a solid block through the layers it may be difficult to hold back the Atlantic, which subsequently moves back in by day 15 on the control. Interesting to see this evolution played by one of the EPS members nonetheless and may be a growing cluster around this potential for pressure rises to the NE.

[Summer Sun]

UKMO extended giving a respite from the deep lows it should be feeling colder

[TEITS]

58 minutes ago, Ali1977 said:

A potential HP setting up near or around Scandy in a few weeks would go against all drivers and the METO long range, so with this in mind I'll say it's prob best just to hope for PM shots. IF a HP does set up to our North I wonder what would be said as to why this happened and what went wrong with the current forecast - it would once again prove any long range forecast for the UK is really just a best guess - I hope it does happen of course. 

Personally I don't think we shall see a solid block to our N/NE. What we may see is enough forcing from the relatively weak high over Scandi (if it forms) to divert the Atlantic SE.

I think im right in saying that the winter of 2013 did bring some significant snowfall events from a relatively weak high pressure system situated to our N.

[snowbunting]

8 minutes ago, TEITS said:

Personally I don't think we shall see a solid block to our N/NE. What we may see is enough forcing from the relatively weak high over Scandi (if it forms) to divert the Atlantic SE.

I think im right in saying that the winter of 2013 did bring some significant snowfall events from a relatively weak high pressure system situated to our N.

It did yes TEITs, and I agree with your sentiments. Their is nothing that I can see in tbe models to suggest blocking/high pressure to our east that eould bring us cold wintry weather. I think it will all come from the NW and North. 

 

[MR EXTREMES]

8 minutes ago, TEITS said:

Personally I don't think we shall see a solid block to our N/NE. What we may see is enough forcing from the relatively weak high over Scandi (if it forms) to divert the Atlantic SE.

I think im right in saying that the winter of 2013 did bring some significant snowfall events from a relatively weak high pressure system situated to our N.

Indeed 2013 was dominated for sometime by some weak heights to our ne.

But currently the heights showing today we're much weaker than Feb 2013.

But if we can get get that jet weaker and little more south then anything is possible.

Right now we need the vortex to take more disruption so we can really squeeze in decent heights.

If lows continue to trundle into Europe then it's only a matter of time before northern blocking finds a home.

Hopefully.

[nick sussex]

ECM and UKMO okay GFS too flat upstream.

The ECM looks similar to yesterdays 00hrs run and the GFS does have the same overall pattern but fails to develop the amplified wave between T144 and T168hrs towards the ne USA.

By T168hrs the games up for any decent high to the ne on the GFS so its really the upstream pattern at that point which is crucial.

If say the ECM is correct then you have to look further upstream to the next possible wave  near the US plains at day ten which could help pull the PV a bit further nw and sharpen up the troughing to the west.

 

 

 

 

[carinthian]

37 minutes ago, Nick F said:

The 00z EPS control shows big amplification NE to the west and north of the UK days 9-10 - which then leads to a Scandi high by day 12, but unless if forms a solid block through the layers it may be difficult to hold back the Atlantic, which subsequently moves back in by day 15 on the control. Interesting to see this evolution played by one of the EPS members nonetheless and may be a growing cluster around this potential for pressure rises to the NE.

Yes, not without interest this chart at t240 from ECM. For some reason the UK has been on the right side of the Polar Trough for much of the early winter season. Maybe if the dig south of the Polar Trough shown above can be maintained and the upper heights strengthen over Scandinavia as NF mentioned there is hope of a more prolonged colder period for NW Europe rather than the transient cold into the British Isles.  GEM model sort supports this set up and looking at the extended UKMO at 168t , that maybe going along these lines. If we can get this set up holding for a few days , maybe we can hopefully stop the Atlantic zonal flow renewal during the Mid Winter period.  Certainly no cold for SE Europe / SW Russia so far this winter looking at this chart.

C

[Duane S.]

Yep, at this juncture anyway (and it will of course change). Unlike November /early December when cold looked like coming by hook or by crook, there is only a small window to keep the Atlantic at bay here or we may have to hold out until mid Jan at least if it turns flat upstream.

If however we can back the vortex NW for a few days with the evolving Pacific wave then 2 wave (second wave somewhere between east Atlantic and Sceuro) setup on the cards, we really could hit the jackpot.

This really doesn't have a straightforward Nina feel about it at all.

[tight isobar]

Interest certainly growing for a 24/48 window of cold and potential transitional snow...into new year1/2nd-jan.

As a minor ridge builds in, and draws a somewhat northerly 'drag'.

And 850s get into the mix becoming negative-to a' persuasive degree.

Worth a stamp of thought.

And already -again some intrest in the very near/reliable time frames.

Edited December 28, 2017 by tight isobar

[West is Best]

1 hour ago, knocker said:

 continuation of unsettled weather 

?

Frosty and cold outside my window, following a snow day: the second this December. The month is half a degree below the (already cold) 1961-1990 mean and likely to end around there or lower: https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

By the way, I'm watching some Alpine skiing whilst typing this and it's fantastic to see such an awesome snowfall across the Alps.

Seeing the snow falling in Birmingham also reminded me very much of winter 1986/6, where we had a couple of heavy snowfalls before January and then a bitterly cold February: second coldest of the century, bowing only to 1947.

 

[tvh3382]

11 minutes ago, West is Best said:

?

Frosty and cold outside my window, following a snow day: the second this December. The month is half a degree below the (already cold) 1961-1990 mean and likely to end around there or lower: https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

By the way, I'm watching some Alpine skiing whilst typing this and it's fantastic to see such an awesome snowfall across the Alps.

Seeing the snow falling in Birmingham also reminded me very much of winter 1986/6, where we had a couple of heavy snowfalls before January and then a bitterly cold February: second coldest of the century, bowing only to 1947.

 

What’s a Frosty doing outside your window??

[Interitus]

11 minutes ago, West is Best said:

 The month is half a degree below the (already cold) 1961-1990 mean and likely to end around there or lower: https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

 

It says 5.2°C, 0.4°C above average (provisional to the 26th)?

[tight isobar]

Gfs 6z going down ecm ooz route for the same time.

The ridge having better designs run to run...and output-to output...

Could be some top modeling coming up...if its colder your looking for...we shall see!??

[bluearmy]

33 minutes ago, s4lancia said:

This really doesn't have a straightforward Nina feel about it at all.

As @catcol pointed out yesterday, the SOI running heavily negative is nino rather than nina. Just as last year when we saw the neg QBO fail (unprecedented or very rare ??) we are now seeing things happening in the Pacific which we haven't before. Caveat being since we have been recording this stuff! 

[danthetan]

6 minutes ago, tight isobar said:

Gfs 6z going down ecm ooz route for the same time.

The ridge having better designs run to run...and output-to output...

Could be some top modeling coming up...if its colder your looking for...we shall see!??

Noted that the GFS 6Z was completely different @96hr to its 00Z run with the placing of low pressure systems so charts @ 8-10day cant hold much credence

[Allseasons-Si]

18 minutes ago, tight isobar said:

Gfs 6z going down ecm ooz route for the same time.

The ridge having better designs run to run...and output-to output...

Could be some top modeling coming up...if its colder your looking for...we shall see!??

Yes,oozes potential

but comparing to the 00z,FL starts at just 96 hrs with the shortwave in the Atlantic replaced with heights,i know we should compare with yesterdays 00z or 06z but it just shows how different it is in just six hours.

just for referance,the gfs 00z and 06z from yesterday morning

 

 

Edited December 28, 2017 by Allseasons-si

[tight isobar]

9 minutes ago, danthetan said:

Noted that the GFS 6Z was completely different @96hr to its 00Z run with the placing of low pressure systems so charts @ 8-10day cant hold much credence

Credence being a bit strong!!

They are operational data ecm/gfs..

And when pattern matching -cross model-- agreement begins to flag...

It has to begin to be noted!!

And that term i hate but will on this occasion use.....

Trend-is your friend!..

Again somthing via output and supporting data to be looking for.

Edited December 28, 2017 by tight isobar

[tight isobar]

2 minutes ago, Allseasons-si said:

Yes,oozes potential

but comparing to the 00z,FL starts at just 96 hrs with the shortwave in the Atlantic replaced with heights,i know we should compare with yesterdays 00z or 06z but it just shows how different it is in just six hours.

 

Yes agree in my post yesterday-i quoted 96hrs- cross suites as FI...but pattern match is coming into play quite considerably!!!

[Man With Beard]

The cold potential for 6/7 Jan starting to firm up on the clusters

And some sort of signal for NE heights remains in the D11-D15 this morning, though still tentative / possibly not in the right place for the UK. Control run cluster - again - with best chance of low pressure going under the eastern block. Trough slightly to the NW still dominant at this stage, though generally not mild: