Model output discussion - summer rolls on

[BlueHedgehog074]

Would like to think the ECMWF has the best handle on the situation since when storms get intense, they can have a tendency to quickly take a left turn and head Northwards. Plus would give those who love the heat another slice of Summer!

[ANYWEATHER]

Evening....Big disagreement from both gfs and ecm  in the near term , but both computer models showing a stormy period  in the next ten days , " Folks Due to the infusion of extropical  storms across the Atlantic"  computer models are in disarray ....Watch This Space

[ANYWEATHER]

25 minutes ago, DiagonalRedLine said:

Would like to think the ECMWF has the best handle on the situation since when storms get intense, they can have a tendency to quickly take a left turn and head Northwards. Plus would give those who love the heat another slice of Summer!

No model as got the best Handle on it .....its the weather which no one can predict!

[Catacol]

10 hours ago, Singularity said:

 

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.

Yes - I think I need to retract part of my comment from yesterday - I've been wrestling with inadequate data for a while and got a bit fed up with it, but today have now worked out access to WDT style charts as well as the excellent Gensini site. (Message to self - never post without checking the data more carefully...)

Relative AAM is currently spiking, and quite significantly. 

AAM forecast over at Gensini's site is similarly impressive 

This should support a much less "flat" pattern in the final third of the month and with the atlantic trough in situ the chance for some long draw SW air returns, though as ever the exact placement of the ridge will be important. Scandy high territory? With atlantic storms in the mix we have some good watching for the time of year coming...and that pesky SW airstream wont cook us in late September either  Still badly need some rain though - wouldnt mind seeing the extended ECM op runs at the moment, toying with wet tropical airmasses arriving on the scene, coming true.

 

 

Edited September 11, 2018 by Catacol

[Frosty.]

Summery potential isn't over according to tonight's Ecm 12z ensemble mean..perhaps not time to put the BBQ away just yet across southern uk!☺

[ICE COLD]

ECM 00z T144 goodbye Ireland

Edited September 12, 2018 by ICE COLD

[mb018538]

Still a wide range of outcomes today - ensembles looking a bit scattergun as they struggle to process ex-Helene as it gets thrown into the mix. Odds on for a warm day or two though in the middle of next week.

[mb018538]

Still a wide range of outcomes today - ensembles looking a bit scattergun as they struggle to process ex-Helene as it gets thrown into the mix. Odds on for a warm day or two though in the middle of next week.

[BlueHedgehog074]

10 hours ago, ANYWEATHER said:

No model as got the best Handle on it .....its the weather which no one can predict!

True, but to be honest my post was about hoping that the ECMWF has the best handle on the situation not that it actually does. 

[Man With Beard]

A long way from consensus on what ex-Helene will do, as mentioned above:

    

But all models going for a tropical Tuesday

  

Maybe even pushing 30C

Edited September 12, 2018 by Man With Beard

[sunnijim]

1 hour ago, Man With Beard said:

A long way from consensus on what ex-Helene will do, as mentioned above:

    

But all models going for a tropical Tuesday

  

Maybe even pushing 30C

To have six months in a year when temperatures get well into the 80s'f would be a record maybe? Would need someone here with that data to hand.

Pretty certain we had an 80s'f day in April this year for some, nothing to stop it happening in early October too I guess,making a potential 7th month!

[mb018538]

2 minutes ago, sunnijim said:

To have six months in a year when temperatures get well into the 80s'f would be a record maybe? Would need someone here with that data to hand.

Pretty certain we had an 80s'f day in April this year for some, nothing to stop it happening in early October too I guess,making a potential 7th month!

We certainly did - 29.1c recorded at St James Park (London) on the 19th April.

The gloom of the second half of August and beginning of September has just made me appreciate how exceptional the first two thirds of summer really were....hard to believe we got 6/7 weeks without a drop of rain.

[Yarmy]

The GFS 6z tracks Helene straight through Ireland:

 

[Badgers01]

period 17th -19th has been repeatedly modelled as storms for days now - somewhere will surely get a blow !!

[Earthshine]

Serious heat in Iberia possible next week.  Warm for most of southern and eastern Britain.  A robust area of high pressure over continental Europe?

[Iceaxecrampon]

Cumbria Reservoirs topped up - possible flood alert this weekend? 

[mb018538]

Gfs and ukmo looking very warm to hot at 144 hours....could see temps creeping up towards 30c in the east if the cloud and rain hold off.

[Frosty.]

There is a mention of warm / very warm spells further s / e in today's update, the Ukmo 12z @ T+144 hours would back that up as it shows very impressive uppers (850's) for mid september and depending on sunshine, mid / high 20's celsius would be achievable in favoured spots..could be another taste of summer for some of us next week.☺

[shotski]

13 minutes ago, Frosty. said:

There is a mention of warm / very warm spells further s / e in today's update, the Ukmo 12z @ T+144 hours would back that up as it shows very impressive uppers (850's) for mid september and depending on sunshine, mid / high 20's celsius would be achievable in favoured spots..could be another taste of summer for some of us next week.☺

Best make the most of it

[Mike Poole]

Evidence now building that this low will stall out west for a period, drawing up a hot air stream from the south.  T144 from UKMO, GFS and GEM:

GFS at T192:

GEM at T192:

Probably not worth looking much further than that given uncertainties.  But does now look like a late warm/hot spell next week, particularly in the SE.  

[feb1991blizzard]

The best member yet this season is ptb 16 on the 12z GEFS.

Edited September 12, 2018 by feb1991blizzard

[Mike Poole]

3 minutes ago, feb1991blizzard said:

The best member yet this season is ptb 16 on the 12z GEFS.

The best member for what exactly?  

Rain, yes granted, but temperatures - it is still September?

[Andy Bown]

The set up for next week reminds me of Ophelia last October. Could we possibly get similar dusty air brought up from the South.

[feb1991blizzard]

2 minutes ago, Mike Poole said:

The best member for what exactly?  

Rain, yes granted, but temperatures - it is still September?

The best for an attempt an Northern blocking, you aren't going to get cold enough for snow this early!!  -   but at least it would feel nice.

[Thundery wintry showers]

The ECMWF 12Z looks very scary for Tuesday, sending the low into mainland Britain without losing much of its intensity: