Model output discussion - summer rolls on

[I remember Atlantic 252]

4 minutes ago, tinybill said:

if  it do we might need  to batten the hatches  down!!

I know I'm in the minority wanting summer weather, majority want it wild wet and windy

[Cheshire Freeze]

2 hours ago, Man With Beard said:

In all honesty I think the ECM is going to be right about the hurricane near the Azores heading our way. It would be very unusual for such a storm to remain stagnant in the mid Atlantic for days and then fade away to the south. The intensity left in the storm as it heads NE would remain in question, as would its direction, so current T216 not to be taken too literally. 

The clusters, by the way, are now buying into a stormier period around the 18th/19th, at least for the NW but potentially for all, as suggested by the deep purples and tight lines near the UK (they have been threatening this for a while but have brought the timeframe further forward today):

And beyond that, the Atlantic remains in full swing as the end of month approaches. Not very typical of recent Septembers!

Given the SST anomalies to our S&W would you count on any storm losing much intensity before it reaches our shores? 

I think this general set up was warned about a few weeks back by some on here, given the cooling to our N and extremely warm SSTs around the UK after such a warm summer.

If nothing else, there could be copious amounts of rain falling across the UK this autumn- there is certainly the potential.

Edited September 10, 2018 by CreweCold

[Man With Beard]

19 minutes ago, CreweCold said:

Given the SST anomalies to our S&W would you count on any storm losing much intensity before it reaches our shores? 

I think this general set up was warned about a few weeks back by some on here, given the cooling to our N and extremely warm SSTs around the UK after such a warm summer.

If nothing else, there could be copious amounts of rain falling across the UK this autumn- there is certainly the potential.

Completely agree. With so many hurricanes on the go, a fuelled up jet and the things you mention, I feel the second half of September could see a very notable storm for the UK - or two. 

[Yarmy]

Pub run has a brief plume and temps pushing 30C in the southeast from T180 onwards. All these tropical shenanigans create a lot of confusion.

[feb1991blizzard]

Lovely GFS, Snow advancing westwards in Russia + vertical WAA into pole.

[Catacol]

ECM is certainly interesting at the moment - ensembles projecting more atlantic influence inbound than their seasonal forecast run on 1st Sept suggested might be the case, and I would agree that all that warm water to the SW might help spawn early pockets of autumnal activity. Quite sharp SST gradient out to our west too....and with pacific forcing currently unremarkable flattish activity pushing ever closer to western fringes looks possible.

 

Too early to get particularly excited about the forthcoming winter season, but the number of weather extremes we seem to be experiencing globally now suggests plenty to keep us entertained. I worry for my children in terms of global climate trends...but from a selfish angle a melting ice cap and impact of bottled warmth in pockets around the world means we can expect the previously unexpected. The incredible destruction of the vortex last season with easterly winds nearly circling the globe will live long in the memory, even if they were so extreme they conspired to end that siberian blast earlier than was expected.

In another 3 or 4 weeks we can begin the traditional dissection of long term drivers. Noone will get it absolutely right - but it is fun nonetheless.

[mb018538]

Plume-tastic ECM this morning, turning very warm through next week as the trough stalls out west. One of a number of options with the tropical low.

Edited September 11, 2018 by mb018538

[I remember Atlantic 252]

8 hours ago, feb1991blizzard said:

Lovely GFS, Snow advancing westwards in Russia + vertical WAA into pole.

deep FI, about same distance away, great EC

[Man With Beard]

So silly season is upon us, with the behavior of hurricanes throwing up all sorts. Some runs this morning like the GFS continue to push ex Helene in our direction, initiating a wet and windy period. However, ECM gets Helene through the pattern faster and it ends up north of Scotland, dragging up a warm southerly in its wake, and temperatures close to 30C in the SE eventually. Looking at all the runs, there currently seems a fair split between both options, with most runs now giving up on the idea of stalling Helene for days by the Azores. 

[Froze were the Days]

Good God!...don't look at the ECM 0z if your not a fan or early Autumn heat, development of a bloody tropical storm interacting with the jet stream causing that!

Edited September 11, 2018 by Froze were the Days

[Singularity]

 

  

Well, it's nice to see the actual AAM finally trending positive and the GWO on a phase 3-4 movement, after the concerns of recent days with the observations refusing to follow the model simulations. Even now, how much AAM rise occurs is questionable - but even a little bit may well be enough to direct ex-Helene in a manner that's very conducive to large-scale warm air advection across the UK from the SSW or S.

The tropical infusion results in an exceptionally warm night or two in recent ECM and GFS runs. The early Wed temps on the 06z GFS aren't far off the long-term average maximums for mid-September.

Once ex-Helene has moved through, the main question is then to what extent the Atlantic trough, boosted by the tropical infusion, is able to overpower the Euro ridge. I expect GFS is displaying some classic bias with that, but ECM may be too, i.e. while the former is too progressive, the latter might not be progressive enough. The balance of power here will have a huge effect on UK temperatures.

[Yarmy]

11 hours ago, feb1991blizzard said:

Lovely GFS, Snow advancing westwards in Russia + vertical WAA into pole.

Somewhat bizarrely (and surely coincidentally) the 6z has almost identical synoptics at nearly the same timeframe:

[feb1991blizzard]

2 minutes ago, Yarmy said:

Somewhat bizarrely (and surely coincidentally) the 6z has almost identical synoptics at nearly the same timeframe:

Yes, these are the pressure / height patterns I would like to see in late Oct / Nov.

[I remember Atlantic 252]

2 hours ago, feb1991blizzard said:

Yes, these are the pressure / height patterns I would like to see in late Oct / Nov.

patterns I wanna see Dec

[feb1991blizzard]

7 minutes ago, I remember Atlantic 252 said:

patterns I wanna see Dec

Yes but if you see rampant zonality in Nov all the way around the globe at 50-60N, then unlikely to see the above patterns in Dec, im not one that subscribes to the view that you cant have a very wet troughy UK in Nov and still have a blocked Dec but you really need the Zonality to not get too far past the Prime meridian, you still want the Russian high to be a major player. its about building blocks.

[Mike Poole]

A look at all models from the 12z suite at T144 (I don't think much meaningful can be said based on the operational output beyond this time at the moment).  Here GFS, GEM, UKMO, FV3 and ECM:

And to give the T850 for the ECM, there's some warmth here:

What happens after is open to question I guess, the earlier 0z suite had heatwave from ECM and GEM and storm from some of the others.  Many variables at the moment, CFS and GEFS differ markedly in terms of AAM forecast, CFS first:

so there is some support if I'm reading these right for the ridge to the east scenario, but at the same time there's the wildcard tropical storms to contend with.  On balance I favour a southerly in about a weeks time giving a final burst of summer, unclear how long it will last.

Edited September 11, 2018 by Mike Poole

[I remember Atlantic 252]

cool EC! still going for mon-wed kinda plume, similar to summer before last, plumes tended to arrive Tue/wed, fresher from the west Thurs, won't get me any 'likes' like 2 posts above, but who gives a damn, 5 likes for no charts, talking about winter

Edited September 11, 2018 by I remember Atlantic 252

[mb018538]

ECM again showing how ex tropical systems can be friend as well as foe - throwing up a big warm ridge of heat, with temps back into the 80s Fahrenheit. Still looks to iron out, could just end up flat and westerly, though the London ensemble mean is almost touching 15c in a weeks time. It’s more likely than not at present.

[Mike Poole]

Actually, and probably just for fun given uncertainty, ECM does go on to deliver a real final blast of summer at T240:

I think this is a decent bet for reasons expressed in my last post, but considerable uncertainty remains.

[Cheshire Freeze]

5 hours ago, feb1991blizzard said:

Yes but if you see rampant zonality in Nov all the way around the globe at 50-60N, then unlikely to see the above patterns in Dec, im not one that subscribes to the view that you cant have a very wet troughy UK in Nov and still have a blocked Dec but you really need the Zonality to not get too far past the Prime meridian, you still want the Russian high to be a major player. its about building blocks.

Completely agree. Even in the extremely wet and unsettled Nov 2009 you could see the building blocks appearing on a hemispheric scale. 

[BLAST FROM THE PAST]

21 hours ago, Man With Beard said:

Completely agree. With so many hurricanes on the go, a fuelled up jet and the things you mention, I feel the second half of September could see a very notable storm for the UK - or two. 

This could get interesting, ex hurricane Helene (as she’ll be when getting to us) could work in our favour and drag in a very warm late summer plume.  One to watch, a big hit of a storm or stay more west and bring S to SE winds.

Interesting to see a lot of extremes apparent

 

 BFTP

Edited September 11, 2018 by BLAST FROM THE PAST

[Froze were the Days]

28 minutes ago, mb018538 said:

ECM again showing how ex tropical systems can be friend as well as foe - throwing up a big warm ridge of heat, with temps back into the 80s Fahrenheit. Still looks to iron out, could just end up flat and westerly, though the London ensemble mean is almost touching 15c in a weeks time. It’s more likely than not at present.

Can't remember too many times of recent years that these type storms which have developed from southerly latitudes have impacted that greatly on these isles in regards to high wind and heavy rainfall (well certainly towards the south)...always seems to suck up very warm air as being the most noteworthy point...all I can say is yuck!

[Frosty.]

Summers over..it's time for a new thread!!!..or is it? the Ecm 12z doesn't agree...Ahhhaaaaaaaaaaaa

Edited September 11, 2018 by Frosty.

[Man With Beard]

ECM mean chart now strongly backing a warm up too. But it's all in the hands of Hurricane Helene. Will she track to our NW, or will she head for Cornwall? 

[Interitus]

Crazy, on the GFS Helene still has a residual warm core as she approaches Cornwall -