Model Output Discussion - 18z 31/10/15 onwards

[MPG]

Here you go MPG, Yes C.S the GFS 6z shows a very disturbed Wintry/Stormy outlook with deep Lows heading further South dragging in colder air with it from the N/W. Certainly an interesting outlook with lots of features to keep tabs on.. A very 'active' period of weather coming up. 

Still can't see it. Not even -5 upper air in place. Anyway all FI.

[Polar Maritime]

Still can't see it. Not even -5 upper air in place. Anyway all FI.

 

With evaporative cooling you don't necessarily need very cold air, And as Sub correctly states above elevation will/does play a big part.. In any case as per my post above, With so much influencing the outputs just now i would just look at it with interest as all these Low pressure systems will be skitting the signals re detail.. 

Edited November 12, 2015 by Polar Maritime

[Cheshire Freeze]

Regardless of some peoples' views on us potentially going into a disturbed nino-esque pattern, the output is reminding me of 2009. Namely that huge Siberian high and the blocking off the east coast of the seaboard. In fact, I'd go as far to say the pattern advertised on the GFS is even more amplified than it was in November 2009. People are talking of the strat engaging with the troposphere but I'm not seeing this at present and low heights will have some job setting up for any length of time in the N Atlantic/Greenland sector whilst we have anomalous heights sat just to the west of this area.

 

We're heading towards the period now where the blueprint for the early winter pattern will begin to show its hand, the fact we're starting to see suggestions that European HP may begin to ebb away, and the continued hesitance of the vortex to locate around Greenland for any length of time suggests to me that heading into winter proper may not be as clear cut as some think. The suggestion of a large Siberian surface high forming is, for me, enough to suggest that things have the potential to get interesting in the extended period.

 

Heading into the later forecast period and into December I'd wager with anyone that the mean jet runs NW-SE rather than SW-NE in our vicinity.

Edited November 12, 2015 by CreweCold

[bluearmy]

Whilst the latter stages of the ecm op seems a tad exuberant, it should be noted that the trop pattern has good support higher up in the strat on the run. (In respect of the lw trough heading down into nw Europe). This patterns also evident on yesterday's 12z op run.

It does look quite mobile so perhaps not a sustained coldish blast if it were to verify.

[Thunder Snow]

Wow Paul that's some impressive rain totals for Cumbria ,

[Captain Shortwave]

The models today all bring a cold shot down from the north from around the 20th. This occurs as the high over NE Canada gets pushed eastward into the Atlantic to allow some form of trough to edge into Europe.

Shown on the ECM

 

Whilst models differ on the fine detail, they all show a similar evolution.

 

But caution must be had here, because it was only 5 days ago that we had the models going for something similar for around the 15th of November, but the ridging over NE Canada and Europe has subsequently been modelled to remain in place during that period.

 

At this time I will feel it is a case of more runs needed and for the evolution to get within the 5-7 day range before I will get interested.

 

It is interesting to see mind you, though the rainfall totals will be of much greater concern at this given time.

Edited November 12, 2015 by Captain shortwave

[phil nw.]

The models today all bring a cold shot down from the north from around the 20th. This occurs as the high over NE Canada gets pushed eastward into the Atlantic to allow some form of trough to edge into Europe.

Shown on the ECM

 

Whilst models differ on the fine detail, they all show a similar evolution.

 

But caution must be had here, because it was only 5 days ago that we had the models going for something similar for around the 15th of November, but the ridging over NE Canada and Europe has subsequently been modelled to remain in place during that period.

 

At this time I will feel it is a case of more runs needed and for the evolution to get within the 5-7 day range before I will get interested.

 

It is interesting to see mind you, though the rainfall totals will be of much greater concern at this given time.

Yes Captain the ECM again finds some extra amplification off the E.Seaboard which digs the downstream trough further south and i would agree let's see if it sticks with it this evening.

It certainly looking cooler overall next week and whatever evolves there is a trend now to bring the jet further south squeezing the Euro high further away.

[Geordiesnow]

The rainfall amounts for the next few days is most certainly of concern, although there is a small chance the rainfall may end up further south than hitting the areas that been hardest hit so far.

 

The potential for severe gales with the ex hurricane does seem less likely now but still one too keep an eye on because the potential is there I feel. 

[SMU]

Early on on the GFS at 114 showing a slower more amplified jet over the states - with slightly better height profiles over eastern canada - may allow for the lows to dig a bit further south on this run....

S

[Cheshire Freeze]

Regardless of some peoples' views on us potentially going into a disturbed nino-esque pattern, the output is reminding me of 2009. Namely that huge Siberian high and the blocking off the east coast of the seaboard. In fact, I'd go as far to say the pattern advertised on the GFS is even more amplified than it was in November 2009. People are talking of the strat engaging with the troposphere but I'm not seeing this at present and low heights will have some job setting up for any length of time in the N Atlantic/Greenland sector whilst we have anomalous heights sat just to the west of this area.

 

We're heading towards the period now where the blueprint for the early winter pattern will begin to show its hand, the fact we're starting to see suggestions that European HP may begin to ebb away, and the continued hesitance of the vortex to locate around Greenland for any length of time suggests to me that heading into winter proper may not be as clear cut as some think. The suggestion of a large Siberian surface high forming is, for me, enough to suggest that things have the potential to get interesting in the extended period.

 

Heading into the later forecast period and into December I'd wager with anyone that the mean jet runs NW-SE rather than SW-NE in our vicinity.

 

Edited November 12, 2015 by CreweCold

[Swave Snow]

My owe my is that the vortex paying the uk a visit on that chart

[Captain Shortwave]

Yes Captain the ECM again finds some extra amplification off the E.Seaboard which digs the downstream trough further south and i would agree let's see if it sticks with it this evening.

It certainly looking cooler overall next week and whatever evolves there is a trend now to bring the jet further south squeezing the Euro high further away.

Certainly there will be a drop off in temperatures compared to the last week or so. One thing I will say is that with heights continuing to be high over a good part of Russia then a Scandi trough looks a good bet going forward as low heights stall and disrupt against that substantial high.

GFS mean at day 6

 

One part of the puzzle fitted at least, what we do need is to rid ourselves over the stagnant upstream longwave pattern, this is the issue I am seeing at the moment as the models try to push the Canadian high east beyond day 6/7 which creates the cold shot. As such it would be nice to see this modelled at the nearer time frame and not put back due to another pulse of cold air digging south into the central Atlantic.

 

That said the GEM is nice at the end of the run. One can dream....... 

Edited November 12, 2015 by Captain shortwave

[bluearmy]

Some need to beware confusing deep depressions and corresponding deep purples with truly low heights which represent the locale of the p/v

At least we have something of interest for coldies which tends to tie in with the ecm op strat data

[chrisbell-nottheweatherman]

Some need to beware confusing deep depressions and corresponding deep purples with truly low heights which represent the locale of the p/v

At least we have something of interest for coldies which tends to tie in with the ecm op strat data

 

How can we be sure that we're not conflating those possibilities when viewing the outputs?

[Cloud 10]

An enjoyable GFS in the mid range this evening with a spear of cold air pointed straight at the UK thanks to the Atlantic/Siberian high double act putting the squeeze on the PV.

 

 

 

 

 

Doesn't seem to be any escaping some silly rainfall totals over the next week or so unfortunately.

 

 

JMA going for the plunge as well..

 

 

 

 

Edited November 12, 2015 by Cloud 10

[Cheshire Freeze]

Hey up, ECM trying to strain out some proper Greenland heights here

 

[radiohead]

Not far off a special ECM run there...

[Cheshire Freeze]

Not far off a special ECM run there...

 

The vortex is being jabbed tropospherically left, right and centre. It gains some ground then takes another hit from +ve height anomalies elsewhere. Good to see if nothing else.

[SMU]

A decent ECM run this eve - especially if you live in the far North with cold air digging in ...

This the pick of the charts

The pattern changer - an inland runner low pressure over the states phasing with PV lobe which develops into a huge storm pumping heights around it ( across the Eastern us into the maritimes & the other side over the Northern pacific )

Huge snow amounts for Central southern canada feeding into the midwest -

This gives the Uk some confidence that the further Nortth you go we could engage the colder uppers..

Possibilites !!!

Lets see where the next 48 hours go

S

Edited November 12, 2015 by Steve Murr

[nick sussex]

Will those shallow lows to the west and sw depart the scene. You can see how these stop the cold air from feeding further south, it looks like a north/south split at the moment, the ECM taken at face value could deliver a lot of snow to the Scottish Highlands and later edging south towards the Borders and on lower ground.

 

Given the overall set up early changes within T144hrs in terms of the pattern being edged further north or south will prove crucial later on in terms of tapping into some more wintry weather.

[nick sussex]

This is the ECM at T192hrs. In black is what SM was talking about that PV lobe, the circled red is the spoiler, you can track from that shallow low eastwards which will mark as the boundary between milder and colder.

 

 

The outputs have overall moved towards something a bit more interesting in terms of cold potential but the problem remains those low heights remaining to the west of the UK.

 

It could still go either way in terms of more UK wide wintry potential, the pattern could get edged a bit further south, equally further north so something to bear in mind.

[Summer Sun]

-8 and -9 850's filtering down into northern Scotland at d9 and d10

 

 

More runs needed of course, but we have now left the period of high pressure dominating our weather and moving into a period of low pressure dominating

 

[nick sussex]

Great post Nick....would love uk wide wintry Synoptics but even if Northern half get snow but all feel seasonal temps will be enough at moment for me....loving the yellow green GH rises...love the use of the pen things are turning colder

Thanks, sadly my artistic skills aren't up to much so the quick paint job is as good as it gets!

 

There are some differences upstream between the GFS and ECM at the crucial timeframes, the former is flatter and doesn't develop that deeper low, the effect is no WAA into Greenland and so no pressure rises there.

 

At this point I'd be happy to just see that Euro high depart the scene as its beginning to grate on me, normally by now I've had the chance to go to the mountains and play in the snow! at this point theres more ice in my freezer. Admittedly the weathers been great down here if you like warmth and sun but you can have too much of a good thing!

[bluearmy]

Signs that the vortex may begin to work it's way towards our side of the NH. However, the usual winter axis of Siberia to ne Canada currently looks skewed to be more along the 0 /180 degree (probably a bit west of that at the moment)

Certainly stuff to be looking at and whilst the ne Canadian high anomoly and siberian ridge maintain, we could be teased for a while longer yet.

[PolarWarsaw]

The November Jamstec is out....

 

 

 

Edited November 12, 2015 by PolarWarsaw