Model output discussion - first hot, thundery plume of the summer

[knocker]

7 minutes ago, mb018538 said:

ECM turns hot later in the run!



Very strange chart there - 18c 850s from a SW'erly??! Normally it's always a a S/SE'erly for air that warm. As a result humidity would be very high in that sort of set up.

A lot hinges on how that low whistling across the Atlantic through early to mid next week engages with the jet stream & where it ends up. Position crucial.

Not that it matters at that range until the earlier developments are sorted but I'm not sure why it is that strange. The ecm is merely indicating an intrusion of the warmer air into the south east which is not being conveyed on the long SW fetch, The air that is is much cooler over the rest of the country

[knocker]

The 0600 sat image

[Methuselah]

Not a bad set of GEFS 00Z ensembles to start the day?

   

   

Though, if it does turn hot later on, some rainfall would be most welcome!

[Singularity]

ECM 00z has an extreme sweep across of hot air straight from the US D8-D10, which combines with a bit of a circulation around from W. Europe to bring 19*C 850s across the SE at the +216 frame.

FV3 by contrast has a much less progressive solution, one of the least so for a couple of days from that model.

A halfway house between the two would set up some pretty intense heat for NW Europe so that’s something to watch out for. A slight increase in the amount of Niño-like forcing from the tropics in the modelling (despite the SSTs now being neutral overall away from the C Pacific) has increased the odds of some Euro ridge resilience against the Atlantic, IMO.

[mb018538]

33 minutes ago, knocker said:

Not that it matters at that range until the earlier developments are sorted but I'm not sure why it is that strange. The ecm is merely indicating an intrusion of the warmer air into the south east which is not being conveyed on the long SW fetch, The air that is is much cooler over the rest of the country

Thanks for that. Very insightful.

As perhaps expected, the OP run sitting outside of the ensemble pack at day 9, but the overall trend is fairly good. The mean is now hovering around 12/13c at day 8,9 and 10 (23rd - 25th July), which means a warm up of sorts is looking more likely than not as things stand - just as the school summer holidays begin!

[BlueHedgehog074]

9 minutes ago, Singularity said:

ECM 00z has an extreme sweep across of hot air straight from the US D8-D10, which combines with a bit of a circulation around from W. Europe to bring 19*C 850s across the SE at the +216 frame.

FV3 by contrast has a much less progressive solution, one of the least so for a couple of days from that model.

A halfway house between the two would set up some pretty intense heat for NW Europe so that’s something to watch out for. A slight increase in the amount of Niño-like forcing from the tropics in the modelling (despite the SSTs now being neutral overall away from the C Pacific) has increased the odds of some Euro ridge resilience against the Atlantic, IMO.

Indeed! As you say, the 00Z ECMWF does show some impressive 850 hPa air over the South-Eastern UK towards the end of its run.

For a bit of fun at that time-frame, but I guess with enough sunny breaks, temperatures could quite easily reach 25*C+ in some South-Eastern spots. 

Great post!

[northwestsnow]

A watching brief for now - EC now gone from an unsettled outlier (last night) to more of a warm outlier this morning.

Little confidence for how next week will look from my perspective , i'm just hoping we don't see any lows becoming trapped near the UK, warmer and more settled towards the SE looks best bet at this range , but then again that's usually a safe bet in any British summer.

The EC mean does support a warm up day 7 onwards, by day 10 it looks very warm across the south in particular ..

For purely selfish reasons this is what i want to see as i'm off work from the 25th July to the 9th of August

Infact the mean above looks very good with any cooler air well to our north towards Iceland.

Edited July 15, 2019 by northwestsnow

[h2005__uk__]

46 minutes ago, DiagonalRedLine said:

Indeed! As you say, the 00Z ECMWF does show some impressive 850 hPa air over the South-Eastern UK towards the end of its run.

For a bit of fun at that time-frame, but I guess with enough sunny breaks, temperatures could quite easily reach 25*C+ in some South-Eastern spots. 

Great post!

Surely they'd be a lot higher than 25C in the SE with that setup?

[summer blizzard]

Although the uppers are excessive today there have been a few GFS runs wanting to slow the trough (and failing after a day or so) so this mornings Euro is not radically out of kilter. Essentially a trough approaches at day 7 and slows/amplifies at day 8 forcing the warm air north.

Euro is a tad strange at day 9 because the flow kind of reflattens but a wave keeps the plume before a more normal day 10 chart.

All in all a good chance of a plume and with no hint of anti-cyclonic flow, I would be looking at potential thunder.

GFS0z shows what happens if the flow slows even more and even earlier.

Edited July 15, 2019 by summer blizzard

[tight isobar]

extremely  quick from me.

however  imo  we are setting up now  for 'perhaps '! the hottest part of summer. ..with what could be locked in conditions  for a while. ..

with a  notable open door....for plume incurance. ..as we relax  the state in the upper most hemisphere! !

[mb018538]

11 minutes ago, h2005__uk__ said:

Surely they'd be a lot higher than 25C in the SE with that setup?

You’d think so - but they’d be held back a bit with high humidity and a lot of cloud (at a guess with that airflow). Perhaps high 20s? For the really hot stuff in the low to mid thirties you really need a drier airmass with a flow off the continent.

 

[BlueHedgehog074]

37 minutes ago, h2005__uk__ said:

Surely they'd be a lot higher than 25C in the SE with that setup?

I admit it was a rough estimate, and also me playing it safe with the 25*C plus, prediction!

[Guest]

1 minute ago, DiagonalRedLine said:

I admit it was a rough estimate, and also me playing it safe with the 25*C plus, prediction!

Exactly right to be cautious as we’ve seen so many times this summer high uppers don’t translate to high surface maxes. To be be honest the ECM would likely have frontal activity draped all over the UK and many places could easily be stuck with drizzle, 20c and 20c dew points.....

[Methuselah]

Hopefully, so nice warm rain, later-on this week?

  

PS: Just managed to download some stuff on teleconnections...that was in order!

[Guest]

Gfs 06z appears to be ramping up a potential plumageddon into next week. With several days well into the 30’s, no silly northeast undercut and a truly explosive ending! It’s similar to the ECM but with the UK benefiting more and the trough to the west digs in more sharply advecting hot conditions over the UK more widely. 

[mb018538]

10 minutes ago, Alderc said:

Gfs 06z appears to be ramping up a potential plumageddon into next week. With several days well into the 30’s, no silly northeast undercut and a truly explosive ending! It’s similar to the ECM but with the UK benefiting more and the trough to the west digs in more sharply advecting hot conditions over the UK more widely. 

Indeed...



Blowtorches at the ready? If the trough holds back in the Atlantic for long enough then a run of high temperatures is certainly plausible. Looks like this is our next 'one to watch'

[Methuselah]

Plumetastic! 

Now, we just need the European HP to prove more resilient than what the remainder of this run suggests?

[StormChaseUK]

Does look like the first real plume of the summer will occur, but proper Atlantic weather will come in directly behind it , something we have not seen for a long long time.

[Guest]

Well the GFS 06z isn’t really an outlier as such and plenty of other ensembles that bring in warmer uppers and for a longer period.

[Methuselah]

Just look at those uppers!

   

   

Just thinking that, bearing in mind the degree of scatter, envisioning the breakdown of a plume, that hasn't happened yet, might be a tad premature...?

Edited July 15, 2019 by Ed Stone

[summer blizzard]

Days 8-10 do indeed produce a stonker of a 2-3 day plume. With low pressure values and an advancing low I imagine it will feel like hell.

[Man With Beard]

The EC clusters indicating a good chance of the second plume of the summer. Weak trough directly to the west, stronger ridging to the SE, as strong as it has been this summer - much more likely to ensure a S of W flow at all levels than the end of June set up had. This chart below is just D8 so we could see a firming up in the models quite quickly (or not, of course!) 

[Guest]

56 minutes ago, summer blizzard said:

Days 8-10 do indeed produce a stonker of a 2-3 day plume. With low pressure values and an advancing low I imagine it will feel like hell.

As in feel like summer and be pleasantly warm unlike the past couple of cool days stuck around 21c.

[BlackburnChris]

Looks like something is trying to build in again , If we do get the Plume next week, without the North Sea Influence this time , temps are likely to be higher , going on the 6z setup , Id go 30deg UK wide and topping Mid 30's Midlands South ... A Week to go yet , but not that far in FI with it starting around +144 . The Chart above shows a nice long draw from the South ... 

 

Edited July 15, 2019 by BlackburnChris

[knocker]

The ext EPS mean is still indicating a westerly upper flow with no great indication of amplification of the European subtropical high, But with positive anomalies over the eastern Atlantic one would expect more influence from the Atlantic high in the day to day phasing of the airmasses  so perhaps a relatively quiet period and as has been mentioned previously, the source of some of the air is over the southern states so temps trending above average

.

Last night's NOAA in the same ball park

Edited July 15, 2019 by knocker