Model Output Discussion 18th Nov.2013-12z onwards.

[bluearmy]

ECM ens for London look heavily clustered to that continental flow later in week 2. This is getting so consistent that we can't really ignore it. the question becomes how strong that flow can become.

Is there a model thread where people dont only talk about FI ? Seems the only thing people here look at. Might just as well head over to maddens page. Lets have some chat about the reasonable charts?

That could be seen as being fairly insulting to those who know how to assess week 2 output gb.Maybe you should work out which posts to read and which ones to scan through.The fact is that there ain't much to talk about a meandering block. Edited November 29, 2013 by bluearmy

[bobbydog]

lol

 

 

forum meltdown warning!!

[nick sussex]

My final thoughts on what has been an exciting(yes I should get out more!) day in the models with so many twists, and a few hints that we could see an extenson to the cold after any northerly.

 

Positively the shortwave near Newfoundland that gets ejected east in much of the guidance except the ECM needn't derail the cold, so the UK has a good chance of a cold plunge from the north with that set up and also the ECM. What we don't want is a half measure hybrid , so if that shortwave is to go east we want this to happen quickly and separate from its partner upstream, no residual energy left behind, and the high to just get flattened rather than tease that its going to follow the ECM then give up the ghost anyway.

 

In terms of the guidance from NOAA in their state forecasts for the ne USA they're not sure either way, they think the GFS 12hrs at least in terms of main low might be more on the money and they highlight the signal for a negative NAO and they think a more westerly track is likely and phasing with the low out of the Great Lakes eventually, this harpoons the route the GFS takes in its 18hrs run, you don't get phasing there as the low slips east into the Atlantic.

 

The possible easterly is well into the future but could become a reality if things go well re a dig of energy into the mid Atlantic, whats great about the GFS 18hrs run putting aside its probably gone a bit AWOL in the early stages is the synoptic example it shows re how you can have what looks like the PV from hell but still get cold, the PV as such isn't really the problem but where it sets up, if its aligned in that ne/sw direction then as long as you get energy splitting from it to support a block to the north of the UK then you can still end up with a Scandi high.

 

So a lot going on today, I certainly look forward to tomorrows trials and tribulations, night all.

Edited November 29, 2013 by nick sussex

[Snowman.]

Is there a model thread where people dont only talk about FI ? Seems the only thing people here look at. Might just as well head over to maddens page. Lets have some chat about the reasonable charts?

Considering how close FI its kind of hard to not talk about 4/5 of a run.

[swilliam]

Is there a model thread where people dont only talk about FI ? Seems the only thing people here look at. Might just as well head over to maddens page. Lets have some chat about the reasonable charts?

The models show over the next few days (until the Northerly in one form or another and with variations on longevity) is that it will be dominated by a cloudy high with slightly below av temps by day and pockets of frost by night.. Variations between models - none so nothng much to discuss - no interesting weather and not much variation. Even our local weather BBC forcaster talked about being colder next weekend (with the caveat that it will be 7 days away)).

Edited November 29, 2013 by swilliam

[damianslaw]

Models offering quite an interesting scenario - very different to the conditions of the last 2 weeks. I think we can safely say a colder spell is on the cards from the NW as we move through next week, how potent the cold remains to be seen, but if ECM verifies then bitter cold would be on the cards with -5 uppers down to the south coast and -10 uppers moving into north scotland.

 

Thereafter, there are three options as I see it -

 

1. High pressure topples over the country and south into France ushering in a mild SW flow.

2. High pressure topples over the country but comes unstuck and settles over the country combined with height rises to our NE.

3. High pressure sinks over the country but at the same time ridges ne into scandi and we end up with a continental east flow.

[forecaster]

Just looking at EC ens clusters for 14th December.22/51 members going for Scandinavian High + Mid-Atlantic Trough (looks similar to the GFS 18z chart shown above).

29/51 for Scandinavian Low + Mid-Atlantic High!

[BlueHedgehog074]

I think that Atlantic Low near the end of that GFS 18Z run really ought to take a nap. Getting itself all wound up and deep with anger just because it can't take out that Scandinavian High...

 

 

(Even though some sort of cold North-Westerly flow is looking possible for late next week and into the weekend with some possible chances of wintry precipitation, I think that Low out in the Western Atlantic probably obviously still needs watching for next week. The faster it comes in and/or the faster and more likely it merges with those Scandinavian Lows, the quicker our possible cold North-Westerly or Northerly flow could get cut off, but it looks like High Pressure would re-amplify behind that Low giving the UK a chance of a second Northerly reload. I guess some people did mention that this was probably going to be no more than a short, potent, cold snap. But it could always be possible we might see an area of the Polar Vortex back far enough West (or maybe something along those lines) to perhaps allow a Scandinavian blocking High Pressure system to develop afterwards to our North-East. (though clearly not guaranteed with more model runs being needed)).

Edited November 29, 2013 by DiagonalRedLine

[Yarmy]

Just looking at EC ens clusters for 14th December.22/51 members going for Scandinavian High + Mid-Atlantic Trough (looks similar to the GFS 18z chart shown above).29/51 for Scandinavian Low + Mid-Atlantic High!

So not a single zonal member?

[bluearmy]

Just looking at EC ens clusters for 14th December.22/51 members going for Scandinavian High + Mid-Atlantic Trough (looks similar to the GFS 18z chart shown above).29/51 for Scandinavian Low + Mid-Atlantic High!

Guess thats a win/win for december, given the background signals arent supposed to be conducive for cold.

[BLAST FROM THE PAST]

Just looking at EC ens clusters for 14th December.22/51 members going for Scandinavian High + Mid-Atlantic Trough (looks similar to the GFS 18z chart shown above).

29/51 for Scandinavian Low + Mid-Atlantic High!

models seem to have liked Steve M's vision today. The ens heading that way. Lets see where we are after this weekend. I am seeing where Gfs is coming from mid range more than ecm. Good model watching for sure. 62 dna continues?

 

BFTP

[Mucka]

GFS 18z ensembles Central England

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=252&y=94

 

There is one rebellious perturbation (P16) within those ensembles which handles the pattern similar to ECM with subtle differences. Goes to show there is always a trend setter. 

[Duane S.]

i posted a week ago to look ne mid December towards Xmas. Lots of doubt being expressed tonight which is understandable enough but I've never been convinced reference Greenland height rises, it's all a bit of a red herring in my opinion. All I can see is a strong signal to move the vortex west, too much energy going in over the top of our MLB. decent but all too brief Northerly with se Europe reaping the rewards. However this could well present an opportunity for height rises over Scandinavia and a linkup followed by a continental flow. What could possibly go wrong?

[Mucka]

Talking of trends.

 

 

[East_England_Stormchaser91]

Talking of trends.

 

 

Looks too much like how the start of 62/63 started up. Scary!

[Crepuscular Ray]

The models show over the next few days (until the Northerly in one form or another and with variations on longevity) is that it will be dominated by a cloudy high with slightly below av temps by day and pockets of frost by night.. Variations between models - none so nothng much to discuss - no interesting weather and not much variation. Even our local weather BBC forcaster talked about being colder next weekend (with the caveat that it will be 7 days away)).

Wow! Next weekend's seven days away. Whatever will they come up with next?

[SP1986]

Good bet it won't be the same type of pattern it's come up with tonight on the 18z. It seems like a high unstable model output tonight, as it looks a little too extreme. As they say it's all up for grabs!

[SE Blizzards]

12z Ens... Only 1 member really wanting a continuation of the cold for more than 3 or 4 days after it initially arrives.

 

Where as the 18z Ens a few members wanting to keep the cold longer.

 

Ens definitely trending colder...

 

Here's the comparison...

Edited November 30, 2013 by SE Blizzards

[Skyraker]

Ensemble watch.

 

[Panayiotis]

Is this Definately for London as it say Debilt?

Sorry you are completely right, it is for Debilt 

[snowbob]

Fantastic output tonight

And loving all the posts that make this the best forum around

The only thing that worry's me a little is , as we all know from THAT ECM

This time last year epic and Stella charts always have too many runs to downgrade.

I know some members don't like that term but I would rather that the models built up slowly and left nice room for improvement, rather than winter wonderland charts with time to be replaced with 90s winters. Just imo

[Panayiotis]

12z Ens... Only 1 member really wanting a continuation of the cold for more than 3 or 4 days after it initially arrives.

 

Where as the 18z Ens a few members wanting to keep the cold.

 

Ens definitely trending colder...

 

Here's the comparison...

Backed by this:

Ensemble watch.

 

[snowbob]

Sorry mods wrong thread

Edited November 30, 2013 by snowbob

[Frosty.]

I'm still buzzin in the after glow of the Ecm 12z op run. Can today be even better? This forum is the BEST.

[Panayiotis]

The latest CFS is one amazing run with cold from 120hrs right through to 500hrs! Lots of snowfall throughout the period, especially chart below! : 

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=174&code=0&carte=0&mode=0&run=10

Edited November 30, 2013 by Panayiotis