Model Output Discussions 12z 01/09/2016

[lorenzo]

06z is bonkers as far as the strat data goes - no doubt

[feb1991blizzard]

Just now, lorenzo said:

06z is bonkers as far as the strat data goes - no doubt

I remember one sunday morning in about Jan 2015, no run previously had suggested this but it suddenly came out with the most ridiculous SSW you could ever imagine, as you will know it didn't materialise!!

[karlos1983]

8 minutes ago, feb1991blizzard said:

Ive never actually heard someone say it but lately yes it has had a habit, but look at the 10mb and 30mb charts now - not bad.

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014110218&var=HGT&lev=10mb&hour=384

 

Your right, I read it. To be fair it feels like the forum talks to me I'm on it so often. I am completely sane, honest 

very nice indeed!! Interesting times ahead for sure!

Edited November 2, 2016 by karlos1983

[BLAST FROM THE PAST]

1 hour ago, Ed Stone said:

We haven't had a storm for weeks, Fred?

Response to poster who was relating to past couple of winters....so post related to the past but with th jet stream being perturbed back then and now....edited post to clarify

 

BFTP

Edited November 2, 2016 by BLAST FROM THE PAST

[Geordiesnow]

Still would not fully rule out any scandi heights making an impact just yet, seen it before when the signal dips only for the models to bring it back again and whilst some sort of heights are still there, the odds of the Atlantic making a return has most definately increased in todays runs. No doubt the PV will gain strength but how that affects our weather is still not fully clear cut.

Hopefully we will see a slow ridge and not the quick progression like the GFS is showing, ECM will be perfect for cold sunny days and frosty nights, perfect Autuminal weather really.

[Mucka]

Fine margins.

 

large consequences.

 

I would think that if the UKMO 120 were correct we would see better trough disruption on the 144 chart than modeled but all a bit academic for now.

I would guess that ECM would be closer to UKMO 120 than GFS. I hope so because, if so, I want to see how it models 144+

 

Edited November 3, 2016 by Mucka

[knocker]

Today and the next couple of days

The transition from the HP influence is under way. Much cloudier than yesterday, particularly as the day goes on in England and Wales, although at the moment clear skies and a sharp frost in many areas. The cloud and rain already into NW Scotland as fronts encroach from the west and these will gradually track SE during the day with cooler air in it's wake

Over the next couple of days the upper low currently to the NW of Scotland will also track SE, and then east, to be in the North Sea by midday on Saturday. This will introduce a cold northerly airflow over the UK, particularly along the east coast where it will feel quite raw, so dig the Long Johns out.

And for the rest of the ten day period with the GFS

Essentially the run be summed up in simplistic terms as the continuing battle and interaction of the warm and cold air masses in the form of the Azores high pressure and the cold air emanating from Canada and the eastern seaboard as the upper troughs track east across the Atlantic. As far as the UK is concerned I think one can say the HP wins on points but the volatility of this set up is such that it could well be the other way around on the next run

Anyway a little detail Tuesday sees the positively tilted upper trough edging SE and the Azores HP ridging NE over the UK and the start of shunting the cold air east.

The energy from the west then makes a spirited attempt to break through the HP and partially succeeds in managing to sneak the upper trough around the high on Wednesday to impact the UK bringing fronts and rain in from the north west.

From there the Azores reasserts itself but the troughs are never far away. So the quick summary for next week is that once the trough has moved away, high pressure from the SW will become more influential and a period of drier weather should ensue with quite a marked improvement with the temps as the week progresses. The main caveat to this is the north may well get some wet and windy interludes as systems swing around the HP. Not too bad once the weekend is out of the way.

Edited November 3, 2016 by knocker

[Ali1977]

Another attempt at a Scandy high by the ECM and the UKMO also has a stab. GFS still says no though , as do the GEFS.

Mmmm, hello ECM Scandy high...this doesn't help us knowing what may or may not happen next week!!

Edited November 3, 2016 by Ali1977

[feb1991blizzard]

Another Murr correction in full glorious flow.

[shaky]

Steve murr looks like you might be correct!gfs is trying for a scandi high this morning and ukmo and ecm still persisting with one!ukmo and ecm look pretty identical!

[Seasonality]

Check out the cold over Europe in the 0z ECM! 

[SMU]

24 minutes ago, feb1991blizzard said:

Another Murr correction in full glorious flow.

Ha -

so we have good solid UKMO & ECM agreement this morning -

ECM - still has a great Easterly flow & 216.

* we cant put all the eggs in the slider basket, however the odds today have moved to 2-1 in favour of euros & with the GFS drifting out to 12-1... 

( hopefully it pulls up lame )

If its going to happen then today is turn around day for the GFS...

S

 

Edited November 3, 2016 by Steve Murr

[mulzy]

Trough disruption after trough disruption on the 0z ECM.  Very good run - let's see if it's ensembles give any support.

Edited November 3, 2016 by mulzy

[IDO]

10 minutes ago, Ali1977 said:

Another attempt at a Scandy high by the ECM and the UKMO also has a stab. GFS still says no though , as do the GEFS.

We know from past experience that the promise of HLB on the ECM op after D6 is abundant but rarely fulfilling. If you compare the ECM mean with the GEFS then it is clear the ECM op is again of limited support:

  

Subtle differences at D10 from both; the usual over ramping of the lower pressure on the GEFS evident, but synoptically very similar.

GEM has also moved towards a flatter pattern of the GFS this morning, D10: 

Just based on past model watching, i would doubt the ECM, but that is just based on previous downgrades; the timing is usually GFS first to kill the slider, then ECM 2 runs later, then UKMO 1-2 runs later. The GEFS from run to run are moving away from the colder option, this morning only three showing up, and the Control supports the op. 

But both options still on the table as models get to grip with the post D6 battle between lower and higher pressure, the next 24 hours will soilve.

 

 

[SMU]

Thats yesterdays ECM 12z mean. its out of date, however watch it change today towards day 6.

[Man With Beard]

Really interesting seeing the consistency of the ECM with the Scandi High (and as I mentioned yesterday i believe this kind of pattern is where ECM has an edge over the other models) - but the question that's dawning on me is - could we actually see lowland snow off this run?

I'm starting to think "maybe". -6C 850s off a sustained easterly flow of more than five days = maybe! But it's early in the season, the North Sea is warm - that would suggest a slightly cooler shot e.g. -8C 850s would be a more confident shout.

Really don't know, but thought I'd mention it as I would not say "no".

[mb018538]

Yes unfortunately it's just too early into the season for -5 850s to really do much other than dust the tops of the mountains! If you like frosty mornings and cool days then you are in luck. Down to -2 here last night, very crisp and clear this morning. Looks like ECM is fighting Steve's corner, while the GFS reverts back to something more typical.

[karlos1983]

12 minutes ago, mb018538 said:

Yes unfortunately it's just too early into the season for -5 850s to really do much other than dust the tops of the mountains! If you like frosty mornings and cool days then you are in luck. Down to -2 here last night, very crisp and clear this morning. Looks like ECM is fighting Steve's corner, while the GFS reverts back to something more typical.

That may be true from a northerly, but not a dry easterly. -5 850's any precipitation likely to be of a wintery nature inland. 

(Must stress This is not a forecast of what may happen)

NAVGEM wants to go to the party 

 

Edited November 3, 2016 by karlos1983

[BLAST FROM THE PAST]

With UKMO developing/expanding heights over Scandi at t120 and supported very similarly by ECM allied by my thoughts that Nov will have massive HP influence......I'm against the GFS.

However, when one model remains stubborn one of 2 things happen. A compromise set up occurs or a massive climb down.  We'll soon find out.

BFTP

[karlos1983]

Interesting, when I looked at the GEFS ensembles graph, I instantly thought this easterly has no chance as none of the members seem interested, but running through the Purbs, many of them give the scandi heights a real go, unlike yesterday, trough disruption takes place either over us or just east of the UK, hence why the graph doesn't really appear to show any support for an easterly.

definitely a move towards the ECM and UKMO

[Summer Sun]

This morning's GEM shifts wind around to a westerly from Wednesday eventually bringing milder air for all

This morning's GFS ens supports temperatures recovering from around mid week with no sign of the 850's heading back below zero for a while

Edited November 3, 2016 by Summer Sun

[Yarmy]

12 hours ago, chrisbell-nottheweatherman said:

 

Forgive me for asking, Moderators (genuine question), but isn't the JMA a bit of a joke model (or at least rather unreliable), or am I thinking of something else?

Hi, Chris. I don't know about the JMA op as it is not part of the verification comparisons provided by NCEP:

However, the JMA does publish verification stats for its ensemble mean:

 

It's 52-week running average is around 0.9 at a 1-week lead time (i.e. T168 as opposed to the T144 numbers for the NCEP chart I've linked) and it's covering a larger area (20N-90N rather than 20N-80N). That is hugely impressive. Compare with the current GEFS mean with a 6 day lead:

As others have mentioned, there is also IanF's anecdotal evidence that it is taken seriously by the MetO.

 

 

Edited November 3, 2016 by Yarmy

[Frosty.]

Looking through the GEFS 00z perturbations, P1 shows potential!

[SMU]

Updated ECM mean -

Whats visible is a move to more energy moving SE across the blocks, the mean is trying to close off a system over East Anglia, however as with an evolving scenario thats moving towards the operational- expect that energy to sharpen up & be further west- - I would suggest Ireland / South west...

12z

00z

even with the lagged time difference ( 12 hours ) there is a very visible change...

S

 

 

[northwestsnow]

HUGE differences between the Euro and GFS this morning! With massive ramifications for the first half of November, euro keep it cold and split the energy, GFS just roles it over the top, and we see with the extended GFS0z what that potentially means, a pretty horrid NH profile.

Normally i'd go with ukmo./ecm but i'm wary that gfs has trumped them in the past and with the GEFS supporting the op i do wonder...

ecm

http://old.wetterzentrale.de/pics/Recm1201.html

http://old.wetterzentrale.de/pics/Recm1441.html

http://old.wetterzentrale.de/pics/Recm1682.html

http://old.wetterzentrale.de/pics/Recm1921.html

At this stage the gfs has the jet rolling into Scandy!