Model Output Discussion - Autumn arrives

[Singularity]

14 minutes ago, mountain shadow said:

The Azores never really makes it and starts to return home at the end of the run opening up the risk of Northerlies at the end of the run. So, maybe a few warm cloudy days for the North West then returning to cloudy, damp and cool.

The trough off Canada would ensure the ridge returns back east going forward but this run sure does give the north a hard time relative to what’s possible with just a few adjustments.

I’ll be surprised if it’s not at the low end of the ensemble spread for temps & SLP in Scotland. The firing of a vigorous low at Scandinavia is pretty extreme.

[kold weather]

50 minutes ago, mountain shadow said:

A pretty depressing ECM run this morning.

The Azores never really makes it and starts to return home at the end of the run opening up the risk of Northerlies at the end of the run. So, maybe a few warm cloudy days for the North West then returning to cloudy, damp and cool.

To be fair the ECM is quite poor for you guys out there, temps keep being suppressed by cloud cover and there is a constant threat of trailing fronts on that 00z run.

For the south, particularly the SE it is still a very nice run, 6 days of 25c+ which is perfectly pleasant at this time of year with the sun being strong still.

[Frosty.]

On the face of it, the ECMWF 0z ensemble mean looks very summery, especially further south, certainly NOT a downgrade, if anything, it looks better than yesterday! ️ 

[sheikhy]

Fantastic ecm mean and after checking the ukmo that looks a belter too!!!bring on the warmth just in time for the summer holidays!!!

[Captain Shortwave]

Whilst the ECM does appear to retrogress the core of the Azores high back westwards, it may not result in a trough over the UK. We could see the surface high split with one in the Atlantic and one being retained over Europe with the trough in-between. This would offer the chance of winds turning southerly for a time in line with a potential plume event. Mean 850s for the start of next week look very warm indeed and would likely support temperatures into the low thirties.

[mb018538]

A fantastic ECM mean this morning if you are in the SE of the country - the 850 mean reaches 10c by Thursday, and stays above here for at least a week, even climbing to 15c from day 6-9. Means are also good elsewhere, though the devil in the detail for western areas will always be cloud amounts, which could render the 850s less useful. Still a lot of charts such as this one below in the models, with it very warm or hot across the E/SE, with the W/NW of all nations struggling in the teens.



The real problem is the lack of rainfall. ECM has 0-1mm across much of the bone dry south for the next 10 days, and the GFS the same out to day 16. If it heats up then there has to be a risk of fires starting out in the countryside.

Edited July 4, 2022 by mb018538

[Mark Parsons]

47 minutes ago, Captain Shortwave said:

Whilst the ECM does appear to retrogress the core of the Azores high back westwards, it may not result in a trough over the UK. We could see the surface high split with one in the Atlantic and one being retained over Europe with the trough in-between. This would offer the chance of winds turning southerly for a time in line with a potential plume event. Mean 850s for the start of next week look very warm indeed and would likely support temperatures into the low thirties.

Much like what the meto are forecasting for next weekend and into next week!!

[Methuselah]

GFS 06Z for next Monday looks ideal:

    

[MattStoke]

Looks like the GFS is setting up for a plume in 10+ days time. Has a front toppling over the high and bringing rain to the northern half of the UK  before then.

[JayAlmeida]

29 minutes ago, Ed Stone said:

GFS 06Z for next Monday looks ideal:

    

The GFS 06z is a really bad run for us up norf. Massive temperature difference between Eastern/Central and Western areas and that's just England and Wales. Scotland fares much much worse.

The high refuses to pass to the east keeping this weeks pattern going into FI. Supressed temperatures and strong winds in the West with a much calmer and warmer picture for the east.

The 00z was a much better run but it now seems like an outlier as the 06z has come more in line with the ECM and GEM.

Edited July 4, 2022 by JayAlmeida

[Paul_1978]

46 minutes ago, JayAlmeida said:

The GFS 06z is a really bad run for us up norf. Massive temperature difference between Eastern/Central and Western areas and that's just England and Wales. Scotland fares much much worse.

The high refuses to pass to the east keeping this weeks pattern going into FI. Supressed temperatures and strong winds in the West with a much calmer and warmer picture for the east.

The 00z was a much better run but it now seems like an outlier as the 06z has come more in line with the ECM and GEM.

"Bad" is subjective - it is not bad if you don't like it stifling hot. The run suits me fine and I am up north

[JayAlmeida]

4 minutes ago, Paul_1978 said:

"Bad" is subjective - it is not bad if you don't like it stifling hot. The run suits me fine and I am up north

Call me picky but I dont find 18c that inspiring for July. Considering the pressure on offer and 850hpa temps being suggested by the models.

[mb018538]

Just now, JayAlmeida said:

Call me picky but I dont find 18c that inspiring for July. Considering the pressure on offer and 850hpa temps being suggested by the models.

Just a very warm tropical maritime airmass doing its bad things. Airmass off the ocean inevitably has loads of cloud tied in. As the air dries out as it crosses to the east of the country, cloud thins out and and the air warms up, setting up the sort of scenario where it could be mid to upper teens in the NW, and mid to high twenties in the SE as shown on numerous charts. If the high would just shift east a bit we'd cut the maritime influence out and it'd be widely more sunny and warmer for all.

Just for fun - way out in FI, the 6z GFS run features three days of 31-32c on the 17-19th July:

 

[mountain shadow]

1 hour ago, Ed Stone said:

GFS 06Z for next Monday looks ideal:

    

Does it?

Looks like the continuance of Autumn for the North West to me. GFS 6z offers three days of warmish (no sun) then a return to norm.

[Staffmoorlands]

A cloudy outlook this week for most of the west and generally  north of Birmingham. If the sun comes out it’s going to feel very warm.

Meanwhile London and the South East warm up significantly with 27c possible by Sunday.

[Singularity]

Curious to see the GFS 06z pick up on the ECM 00z pathway but take it a bit further. I expect it's also from the low end of the ensemble spread for northern UK, but it at least backs up what I and Captain Shortwave said regarding what happens after day ten (not a northerly), even if it is a very messy outcome on that run.

When it comes to watching for a potential heatwave in the 8+ day range, it's best practice to stick with ensemble products and see whether there's more than a smattering of support for such conditions. That's certainly the case for London this morning. Birmingham too, when allowing for the heatwave threshold being a degree or two lower:

 

 

Further north, the spread inevitably lowers and once you reach the likes of Glasgow, it mostly tops out in the mid-20s. This is not surprising considering the origin of the high pressure system and the signals for it to drift toward Central Europe, meaning the core of heat is focused over the western half of the mainland and potentially southern UK.

From the expected position early next weekend, a heatwave in Scotland would require the high to drift a bit northward and then stall, but signs are, there will be too much of a zonal flow tied to a +NAO, +AO pattern for that to occur. What raises the heatwave odds for the south lowers them for the north - nationwide heatwaves are rare for a reason.

Still, there's a chance of hot weather reaching Scotland for a time, as around half the 00z ECMWF ensemble runs set up a slow-moving low to the west of Europe at some point between 14th and 19th July, leading to a big northward push to the (in a lot of runs very) hot airmass.

 

Edited July 4, 2022 by Singularity
Accidental Image Error

[*Stormforce~beka*]

Have we got rid of the 40c+'es?

[Don]

12 minutes ago, *Stormforce~beka* said:

Have we got rid of the 40c+'es?

For now......

[northwestsnow]

3 hours ago, JayAlmeida said:

The GFS 06z is a really bad run for us up norf. Massive temperature difference between Eastern/Central and Western areas and that's just England and Wales. Scotland fares much much worse.

The high refuses to pass to the east keeping this weeks pattern going into FI. Supressed temperatures and strong winds in the West with a much calmer and warmer picture for the east.

The 00z was a much better run but it now seems like an outlier as the 06z has come more in line with the ECM and GEM.

That chart sums up NW England .

Incredible temp differences at such short distances locally.

Absolutely depressing.

[Fourty Point Three Degrees]

4 hours ago, JayAlmeida said:

The GFS 06z is a really bad run for us up norf. Massive temperature difference between Eastern/Central and Western areas and that's just England and Wales. Scotland fares much much worse.

The high refuses to pass to the east keeping this weeks pattern going into FI. Supressed temperatures and strong winds in the West with a much calmer and warmer picture for the east.

The 00z was a much better run but it now seems like an outlier as the 06z has come more in line with the ECM and GEM.

the 6z is an outlier and doesn't get much support in ensembles, a lot of the members are hovering at the 20C hpa with some rising towards 25C....  and a lot of members going for 15C to 20C hpa for Liverpool.. 

GEM has several crazy hot members rising to 25c in London 

 

GFS is known to drop heat waves in FI then bring them back in a closer range. 

[Guest]

3 hours ago, *Stormforce~beka* said:

Have we got rid of the 40c+'es?

P23 in the 06 GFS ensembles features a lone 40C. A run here or there is still tending to churn one out in deepest darkest FI.

[sheikhy]

Excellent ukmo!!!!and a much better gfs compared to the 06z!!!!and the lack of rainfall is quite something!!!

[Singularity]

For 12th-14th July the 12z GFS is the closest I’ve seen to the 18z of two days back that produced the chart with widespread 40+ temps in southern UK.

Just thought I’d note that in case this run happens to continue heading in a similar direction, which would be interesting to see and give a sense of whether what goes in early next week has much bearing on what takes place toward the weekend.

[mb018538]

Decent looking runs today. Probably staying very warm right out into next week and perhaps out to mid month. No point looking beyond here at the moment.



Temps perhaps nudging over 30c early to middle next week? Very warm out til then, especially in the SE.

[Staffmoorlands]

Sunday and Monday are looking cloud free and hot even for NW England and most of Scotland