Model Output Discussions 12z 01/09/2016

[phil nw.]

No sign yet of a real push from the Atlantic despite the fresher air now getting in behind the storms and rain.

The fax on Monday for example still shows fronts slow moving and weakening across the UK as the Azores high starts to ridge ne towards heights already over Scandinavia.

Continental/Azores heights then look like keeping the south east more settled during the coming week with any frontal systems affecting the north west more and weakening as they come south east.

We can see the 06z gefs jet stream stamps for a week today showing it's favoured path going north east to the north west of Scotland

and the day 10 mean pattern from the GFS Jet stream and 500hPa heights alongside the ECM day 10 mean 500hPa pattern

 

underlines the expected north/south pressure differences,which really is something more late September-like.

Still looking quite a decent setup for many with plenty of fine and dry weather away from the far north west although temperatures much closer to normal..Quite a change after the recent meridional jet pattern with the UK often on the warm side of the Atlantic trough/Continental heights which has brought some notable heat through the first half of September.

 

 

[Frosty.]

Interestingly, the GEFS 6z mean charts I posted on the previous page has support from the MO with perhaps a longer spell of dry and warm weather developing for a time later this month. In the meantime, an Azores ridge should bring a decent weekend for most of the uk with the exception of the SE tomorrow and the far NW on sunday but a band of rain pushing southeastwards across the uk on sun night into mon morning and thereafter it's a nw / se split with the coolest and most unsettled weather across the northwest of the uk and the best of the pleasant conditions towards the southeast but with some rain at times and then things could be looking up for the majority of the uk during the last week of september.

Edited September 16, 2016 by Frosty.

[Frosty.]

The Gfs 12z shows another summery spell during late september with temps into the low to mid 20's celsius across the southern half of the uk..this is something the latest met office update also suggests is possible.. so, we may have more summer like weather to come!

In the meantime, it looks like a decent weekend across most of the UK thanks to a ridge of high pressure and then next week looks more changeable but with the most unsettled and cool, windy weather across the northwest of the BI with the best of the pleasant conditions further south / southeast..and then more and more of the uk becomes warmer and more settled, at least for a time by the end of next week into week 2..fingers crossed.

[I remember Atlantic 252]

hope so Frosty, never know, timed for Tuesday-thursday again, feels as though that makes it more likely to come off

[Summer Sun]

Looking at UKMO it doesn't look too bad next week with any low-pressure systems staying to the NW of Scotland with temperatures generally around average possibly slightly above for the SE

[Frosty.]

5 minutes ago, I remember Atlantic 252 said:

hope so Frosty, never know, timed for Tuesday-thursday again, feels as though that makes it more likely to come off

Fingers crossed we haven't seen the last of the summery weather, I'm seeing positive signs. :- )

[phil nw.]

One recent post has been removed.Just a reminder to keep general chat to other threads-Model output views only in here please all.

Thank you.

[Frosty.]

I'm seeing positive signs from the GEFS 12z mean that later in september could become warmer and more anticyclonic, at least across the south of the uk as high pressure builds in close to the south..we may not have seen the end of summer like weather for this year!

[Matthew.]

Well the ECM has a new development taking Low pressure NW-SE midweek next week. Not good for summer lovers but thinking longer term could this be setting a trend for the winter? We all know what that could mean when the Azores high retrogresses

Edited September 16, 2016 by Matthew Wilson

[Frosty.]

Don't give up hope of another summery spell before september is out, some of the GEFS 12z perturbations look peachy for warm anticyclonic weather across most of the uk later this month...The fat lady isn't singing yet!

[Singularity]

While GFS and UKMO are consistent with the vague ridging through the UK in the 5-6 day range, and ECM with its disrupting trough, GEM goes mad with powering the jet stream south of the Scandi ridge (what is this, winter 2009/10?!), and JMA races a moisture-laden low across the Atlantic and into the base of the main Atlantic trough, with violent consequences:

 

 

...so it seems all is not well with the models in terms of getting to grips with next week's pattern. 

Despite this, most are trying to build a ridge into Europe in the 9-10 day range, with lower heights digging toward the Azores. This looks to me like a lagged broad-scale response to an active MJO in phase 4, such as we will continue to have over the next few days. The million-dollar question (for some investors, at least!) is how that interacts with the weakly negative GLAAM state.

[damianslaw]

Mmm heights to our NE, heights over the azores wanting to ridge NE to join hands, but also not especially low heights over arctic regions, indeed models toying with moderately high heights over Greenland - we could end up with the trough becoming slow moving and forced down across the country with azores heights then retrogressing and heights to our north becoming dominant.. if we see trough disruption a southerly could quickly become a northerly.. lots of options, a late warm dry September certainly can't be banked on at this range. 

[Frosty.]

1 hour ago, damianslaw said:

a late warm dry September certainly can't be banked on at this range. 

Of course it can't be banked on and I don't think anyone has said it is but at least there are signs from the meto & GEFS mean that we could have a favourable sw / ne aligned jet enabling the Azores high to build in close to or across the south of the uk later this month...I'm hopeful we will see another taste of summery weather before september is over...plenty of time for the usual Atlantic dross during Oct / Nov.

Edited September 16, 2016 by Frosty.

[summer blizzard]

Probably worth saying that the models have (by then a Hurricane) Karl recurving and joining the jet stream close to day 10. As ever, keep a cautious eye on the models when this happens. 

[DR(S)NO]

14 minutes ago, summer blizzard said:

Probably worth saying that the models have (by then a Hurricane) Karl recurving and joining the jet stream close to day 10. As ever, keep a cautious eye on the models when this happens. 

 

Or..... Hurricane Frosty as it's known here on the Netweather Forums..

 

Quote

 

[Rocheydub]

53 minutes ago, summer blizzard said:

Probably worth saying that the models have (by then a Hurricane) Karl recurving and joining the jet stream close to day 10. As ever, keep a cautious eye on the models when this happens. 

Indeed, have been keeping a watchful eye on this. Could be the first Autumnal storm of any meaning. Path and strength all up for grabs at this juncture of course!

[Summer Sun]

Nothing too bad on this morning's ECM with high pressure never far away especially from the south and SE keeping low-pressure systems to the NW and it's here is where we'd see the bulk of any rain

[legritter]

Morning gang ,went for an early walk with the loyal dog this morning ,Felt very nippy and autumn like ,what a turn around from a couple of days ago no wonder it all went with a bang .

Looking at current charts and Data and some very nice weather to be expected with a few minor fronts bringing mist and murk ,some interesting developements later in the outputs ,but all depends on where high pressure sets up , could be interesting with some colder air in the mix now things in the far north are cooling off ,cheers all ..

[sundog]

This chart a long way out of course but the hp north of scandi and some hp over greenland caught my eye.

Ive been thinking the last day or two looking at some of the charts of a possible chilly first week of Oct. Just a thought anyway.

[Matthew.]

The GFS 6z looks like bringing a fine Friday, Saturday and Sunday next week. Lots of fine settled conditions with 1020mb+ south of the border The final chart for fun is the 3rd October, Indian Summer anyone?

Edited September 17, 2016 by Matthew Wilson

[sundog]

56 minutes ago, Matthew Wilson said:

The GFS 6z looks like bringing a fine Friday, Saturday and Sunday next week. Lots of fine settled conditions with 1020mb+ south of the border The final chart for fun is the 3rd October, Indian Summer anyone?

I know there isnt much point talking about the last chart since it is for Oct 3rd ,but that hp would not be too much on the warm side. So that last chart would not be what one would call an indian summer chart.

 

Edited September 17, 2016 by sundog

[I remember Atlantic 252]

11 minutes ago, sundog said:

I know there isnt much point talking about the last chart since it is for Oct 3rd ,but that hp would not be too much on the warm side. So that last chart would not be what one would call an indian summer chart.

 

yes, colours too green, need southerly for summer in 0ct

[summer blizzard]

The last chart is cooler than it looks but it would be good (sunny, frost, fog)..

[mb018538]

12z is starting to show some warmer stuff appearing again towards the end of next week....we might get one more flicker of summer before September is out.

[Matthew.]

Found this interesting from the CFS for December. The first chart was December 2015 forecasted September 2015 and is pretty accurate with high pressure to the south pumping up warm air. Now the second chart is for December 2016 and notice all the Northern blocking in red. A complete reverse forecast for this year