The morning runs aren't very inspiring around the UK for the period Sunday-Friday next week, as disturbances off the East U.S. coast engage with the main Atlantic jet and develop into strong storm systems south of Greenland which only slowly progress SE.

By contrast, a very promising sequence of events is now being modelled for the U.S. and Canada. Around 6 days out (+144 hours), a shallow trough develops somewhere in the vicinity of Texas, and by day 7 this can clearly be seen progressing eastward beneath a Canadian High that is being supported by that trough (below-left chart). ECM shows the same sort of thing but the trough is further south.

This feature represents a diversion of low heights away from the Canada/Greenland area. Both ECM and GFSP show height rises over Greenland as a result, ECM by day 10 and GFSP by day 11 (below-right, note the circle of green indicating those higher heights).

This is something I've been looking out for over the past week, as it represents a milestone on the path to high latitude blocking.

It should encourage the Atlantic jet to track further south, increasing the extent to which it digs down to the Eastern Med. and attempts to undercut the Siberian High (not captured by the GFSP run until a messy day 15-16 attempt, but nicely shown by ECM on day 10).

It ought to add a bit more punch to back-end northerlies as well, with more substantial mid-Atlantic ridges, but a flatter pattern as per the GFSP 00z could occur instead, which brings a roller coaster of temperatures plus a lot of rain.

I must caution that this all comes from a U.S. progression previously absent from the model output, so although it's at day 6, an equally fast backtrack is not out of the question. After all, the GFS 00z and 06z op runs have it as a faster feature that tracks NE, developing in the western North Atlantic and shifting the mean trough position quite a way west while providing no real height rises over Greenland.

It also appears that even if we do get the ball rolling, westerly momentum may take at least a couple of weeks to subside to the point at which high latitude blocking can really start to have a say in our weather beyond the southward shift in the storm track.

Of course, this all assumes that the models are handling the earlier East U.S. low in the right way this time round, and aren't about to shift it south and prevent it phasing with the Atlantic jet just as they did for the coming week. That would really shake things up but there's less sign of it occurring this time around.

Would 'Iceland' be the Frozen foods supermarket on the Algarve ?

James, do you think the low exiting the US from a much more southerly point will be able to budge that very resilient Azores High?

I remember in 2010, the AH relocated well to the west of the Azores - in fact almost over the SE'ern US and Caribbean. This allowed (or was driven by...) the Jet plunging southwards someway to the West of the UK & European landmass, allowing HLB'ing to influence our weather.

Like with last winter, the AH has been resolutely anchored in its usual place, so any fledgling HLB'ing is squeezed out by lows pushed through by the Jet surging over the AH.

I guess it all comes back to that 'what causes what' question; what made the AH move westwards in 2010? - or, was it a case of the AH moving. which then created the more meridional Jet? (simple terms I know, but you know what I'm getting at)

All I can see in the output at the moment is a cycle of ridge trough, ridge trough as the weather systems grind their way over the dominant high pressure to our SW. It looks good for northern hills at times, though I'm doubting I will see anything wintry IMBY. It's quite seasonal though, and as I like my weather seasonal, I'm not complaining. It will provide some day to day variety, with some spells of rain and gales, and the odd clear and frosty morning. Better by far than endless days of anti-cyclonic gloom, or waving stationary fronts bumping up against immobile blocks just to our east, giving unhealthy amounts of rain. In terms of real cold wintry weather though, nothing remotely in site. No sign of any real cold air to speak of west of the Urals or even beyond.

However, I'm always interested to read in this thread about rumours of a pattern change, or things that might trigger a pattern change. But at the moment I'm struggling to see it in the current output.

I completely agree - let's hope the internal models that the Met Office and ECMWF have access to show more than we're able to see, as I don't see anything in the output to suggest anything particularly exciting.

tally, has there been a seismic geologic

shift causing Iceland to move LOL ?

Tally was referring to the 00z run - which showed LP to the north of Shetland, Arctic air running down across the whole country and snow showers, especially around Irish Sea coasts and for Ireland more generally.

The 06z run, not surprisingly, shows the complete opposite.

Im finding it does this alot on here.  The image pasted is a more a paste of the locastion - not the image.  Where the image location changes - so the message image does too.

Look on the scottish thread in one of the stickies.  Theres one i just looked at that yesterday showed a glorious highland moutnain, where as it now shoes todays cloudy and murky view.

Might need to rethink the pasting - as it will skew any attempt to view these threads in days/weeks/yearas to come.

good point. Sorry Tally! I know your a good poster. By the way, I am still experiencing difficulties when replying to posts by I phone  

Sorry off topic, but yes I have the same problem..

The best way to describe the issue is often you can't get the cursor to go where you want it to.. If that makes any sense at all? 

Brian could you possibly look at a fix for this as it is a real pain in the bum..

Do you mean when you're quoting a post? Quick reply seems fine now. 

QQ Brian - not sure if its just me but i think the ensembles are a little bit mixed up - the dates along the bottom are showing as the model run names.

Sorry to sound like its all negativity on here about TWO - it really isnt. 🙂  - just thought i would raise it to your attention incase something was wrong.

One of the GEFS6z control run data files was corrupted during download. The date labels are wrong but the snow row is correct as are the other plots with the exception of the control run.  

This happens occasionally but if it's one of the 20 perturbations you're unlikely to notice it. The same problem can occur with the GFS op run but because it is used in the place or postcode forecasts a number of automated checks are in place. If one of these is failed the data file is downloaded again.

yes Brian, if you want to edit what you have just written before posting then it can be really difficult to insert the cursor in the previously written sentence before editing. Hope this makes sense!

LOL. It's an amusing situation when someone posts exciting remarks about a chart using a direct link and then, as sure as anything, it completely changes a few hours later.

It does however illustrate the volatile nature of the longer range output. A solution to anchor comments with charts would be to copy and host the image independently and link to the host URL rather than the original site.

great thanks for the feedback.

I've just replaced the corrupted file and regenerated most of the GEFS plots so the date labels should now be correct. 

Also, I will re-write the download scripts soon and put code in place to automatically identify and fix the most common problems.  

It's sod's law how the 6z pulled your trousers down - but that isn't a bad chart in the wider scheme of things, taking into account how far south the Atlantic trough digs, with the AH displaced westwards.

The potential snag is that low north of Siberia, keeping the gate open for that low over Iceland to move NE, but then, that may allow the expansion of blocking to our north.

Same problem as the others on iPhone and iPad. I actually brought this up in admin ages ago 

the cursor has a mind of its own and when you try to insert a smiley at the end of a sentence it takes attempt after attempt as they usually end up in the middle of word or sentence.

Hi all,

Here's today's video update;

A Little Milder Next Week?

http://www.gavsweathervids.com

Chilly this week, a bit milder next week, perhaps.

With temps to our east remaining above or well above average it would seem any proper cold in the shorter term will have to come from a northerly rather an an easterly quarter. However most of us know how the continent can quickly grow cold. Just as of now this is not the case.

That's 850 Alan, which may not be the best source of info regarding the 2mT values in W Russia. It's also modelled and their ensemble suite can change as quickly as ours does with regard the formation of a block.
You're right with respect for a true 'beast' you need Moscow's 850s to be sub -25, but even in 1987 the Arctic plunge did not arrive until around Christmas to our east and it was another two weeks before we got it advected our way.

The thing is we do not know if it will change in terms of a block & colder weather over there, it's purely hopecasting. And it's not just western Russia. Places like Helsinki and Stockholm are not much colder than here in the short to medium term.