Model Output Discussion - Into Summer 2020.

[WxHerts]

GEM literally always overdoes uppers by 2/3c, even in winter 

[Mark wheeler]

Well One thing I’ve noticed about the Gem tonight is it shifts the core of the heat east much quicker than it’s previous 2 runs. This probably because the Daily Express released a article quoting the model and saying 36c will be reached , As soon as that paper speaks it never ever happens

[East_England_Stormchaser91]

1 hour ago, I remember Atlantic 252 said:

FI, but 2nd GFS run now for thunderstorm fans for Sunday 28th, typical chart as this setup tends to favour eastern areas, my area never does that well in plume setups, much better Sat to Wed just gone

The directional steer over the heating of the landmass plays a huge part. Dew points and sufficient temperatures max out much better over a longer stretch/track of landmass, uninterrupted by sea temps modifying it. The Northwest was the prime spot for storms to end up as matured beasts with that SE fetch off the continent and all of England. Lincolnshire is usually the default location with a S/SW fetch. 

[Zak M]

Marco Petagna tweeted about the 564dam potentially pushing its way up to the UK and it's visible on the synoptic chart.

Our true summer could be on the way... hopefully!

https://twitter.com/Petagna/status/1273994420057264128/photo/3

Edited June 19, 2020 by Zak M

[Zak M]

ECM is currently rolling out and we're off to a good start at 120...

   

[Mark wheeler]

Navgem also like the gem Shunts the heat east but unlike the Gem the Heat makes a comeback . Hooray

Edited June 19, 2020 by Mark wheeler

[Methuselah]

Not a massive amount of support for the GFS 12Z op's plummeting temps (June 29th) from the GEFS ens... but, there is some. So the likelihood of any extended heat is still very questionable IMO:

    

    

But, add on the obligatory 3C to the op's standard 2m 'loony' temps, and the 12Z becomes something of a stonker: 16 straight days of 21C+ temps?

The NH profiles are quite spiffing, too:

    

    

That said, I do feel that some of these current model-runs are seriously pushing the envelope?

[Guest]

Its going to be tough to see the heat sticking much long than Thursday looking at the ECM 144. Still 30C possible Weds/Thur at least. ECM has maxes of 26C plus confined the wash to Southampton south eastwards on Thursday on WXcharts, with 30c likely around London.

Uppers remain warm Friday however a surface flow looks more south westerly so it should be cooler on Friday. Clearly GFS builds heights a touch more to our north east, where's ECM have pressure a little lower allowing low pressure to move closer to the UK. 

Edited June 19, 2020 by Guest

[I remember Atlantic 252]

Westerly, but still looks hot away from W Scotland/far W/NW

[MATTWOLVES 3]

Extensive warmth again by day 7..

[Guest]

2 minutes ago, MATT said:

Extensive warmth again by day 7..

I don't think those uppers are going to translate into the temps at the surface we'd expect due to the surface flow, maxes of ~24-25C in the extreme east low 20's further west. Hopefully it doesn't end on a bad note and drop pressure down over us from the north. 

[mb018538]

2 minutes ago, Alderc said:

I don't think those uppers are going to translate into the temps at the surface we'd expect due to the surface flow, maxes of ~24-25C in the extreme east low 20's further west. Hopefully it doesn't end on a bad note and drop pressure down over us from the north. 

24/25c maxes by Friday and Saturday, and mainly confined to the east as the flow turns more westerly and the continental feed Is cut off. Perhaps ECM a bit over eager in pushing everything away, ensembles will be interesting. 

[Guest]

Ugh not the best end to ECM as it starts bringing in an upper trough. Hopefully an outlier however for the past few days ECM has not been keen on prolonging the warmth beyond Thursday to any real degree. Looks like a stand-off between ECM & GFS...

[Guest]

1 minute ago, Mark wheeler said:

Here comes the Azores High 

That's this mornings 00Z run......

[Mike Poole]

Good set of runs this afternoon again, and indeed in the morning.  There is still a lot of uncertainty from reasonably early on in the runs, so the longer term output I think is better led by the teleconnections than the models.  I will be looking forward to getting the view of the shorter range models and ensembles on the max temperatures middle of next week.

JMA keeps the heat through to Saturday at least, T192:

[Mark wheeler]

4 minutes ago, Alderc said:

That's this mornings 00Z run......

oops , Thanks for pointing out, Clumsy fingers I did think it was strange . Deleted , Apologies Everyone .

Edited June 19, 2020 by Mark wheeler

[Mark wheeler]

3 minutes ago, Mark wheeler said:

oops , Thanks for pointing out, Clumsy fingers I did think it was strange . Deleted , Apologies Everyone .

Let’s try again , Here comes the Azores High

[northwestsnow]

Excellent runs this evening.

A battle royal brewing in FI between the Azores high and the Atlantic lows..

In the reliable summers a coming..

[mb018538]

Not worth fretting over next Friday to Sunday yet - they are 7-10 days away and well out of the reliable range. We will get clarity on those and the extent of the heat as the weekend progresses!

[Zak M]

Trying to improve my understanding on the 8-10 day 500mb mean charts so I'll be posting these charts too. If you see a mistake made by me, please let me know, thanks  

So I think the chart below is the 12z of the GFS and ECM. ECM on the left puts us under a high so that should be good for us southerners, but it might be a tad more unsettled in the north. GFS on the right pegs the high to the right hand side and a low to the left or in the Atlantic. I imagine this would destabilise the air inside the warm, humid airmass that the GFS is showing and would give way to some thunderstorms.

[MATTWOLVES 3]

Just a few charts for next week's heat, the GEM is the pick of the bunch and brings potentially... 31-34C..

[northwestsnow]

EC 12z para ends very nicely indeed..

Edited June 19, 2020 by northwestsnow

[damianslaw]

1 hour ago, Alderc said:

I don't think those uppers are going to translate into the temps at the surface we'd expect due to the surface flow, maxes of ~24-25C in the extreme east low 20's further west. Hopefully it doesn't end on a bad note and drop pressure down over us from the north. 

Yes the surface flow is from off the mid atlantic, no continental or long drawn southerly flow. 

[MATTWOLVES 3]

Pretty good mean, especially for those away from the far NW.. Perhaps Summer proper is about to start... A very good evening to you all..

[Singularity]

1 hour ago, mb018538 said:

24/25c maxes by Friday and Saturday, and mainly confined to the east as the flow turns more westerly and the continental feed Is cut off. Perhaps ECM a bit over eager in pushing everything away, ensembles will be interesting. 

Please note, however, that these are 'at the time' temps as opposed to the actual maximums - and for some reason, the 6 pm temps are typically 2-3 degrees lower than those, despite the fact I'd not expect more than a degree of loss from the peak at that hour. Here's a link to Friday's chart - though annoyingly, this site doesn't display the detail very well unless you look county-by-county.

https://weather.us/model-charts/euro/england/max-temperature-6h/20200626-1800z.html

There's a 27 to be found in eastern London. Not that we should be looking at such details when there's so much model divergence going on. One thing I've not seen mentioned yet is that UKMO handles the Atlantic trough very differently to both ECM and GFS, further muddying the waters. It was the same for the 00z runs. Each model has stood by its own take on matters. Reminds me of what went on for a while with respect to last weekend's wandering low!

Edit: Forgot to mention that I've also been unimpressed with ECM's surface temp modelling, noticing a frequent shortfall of 1-3 degrees on the actual. Similar to GFS, but not quite as persistent or strong with the errors.

Edited June 19, 2020 by Singularity
Bias note