model discussion Model output discussion 11th July onwards

[damianslaw]

A blocked set up for the foreseeable.. better late than never.. pity couldn't have set up earlier this month. Oh well. Lots of usable dry weather ahead, no sign of rain for a while. We've had lengthy bouts of dry weather this year 10-14 day interludes followed by wet spells. 

What factors might trigger a breakdown to unsettled again? 

[stodge]

30 minutes ago, damianslaw said:

A blocked set up for the foreseeable.. better late than never.. pity couldn't have set up earlier this month. Oh well. Lots of usable dry weather ahead, no sign of rain for a while. We've had lengthy bouts of dry weather this year 10-14 day interludes followed by wet spells. 

What factors might trigger a breakdown to unsettled again? 

Very true - up to a fortnight more of E'ly or NE'ly winds for downtown East London from the 12Z outputs - extraordinary for any time of year.

Breakdown?

Some thoughts - one possibility is from the south with the European LP encroaching north as the HP declines - the E'ly flows continues but becomes increasingly unstable.

Another option (probably the favourite) is the HP sinks south, probably to the south west and allows Atlantic systems to encroach from the north-west.

An outsider would be proper retrogression and a Scandinavian trough with LP moving down the North Sea bringing rain, showers and cool conditions.

That's my three on first thoughts.

[Mike Poole]

38 minutes ago, damianslaw said:

A blocked set up for the foreseeable.. better late than never.. pity couldn't have set up earlier this month. Oh well. Lots of usable dry weather ahead, no sign of rain for a while. We've had lengthy bouts of dry weather this year 10-14 day interludes followed by wet spells. 

What factors might trigger a breakdown to unsettled again? 

To add to what @stodge has suggested you have to factor in ex-tropical storms at this time of year.  And they could do one of two things, aid breakdown to unsettled, yes, or promote a longer term settled period through most of September.  

[Northwest NI]

On 24/08/2021 at 19:21, Mike Poole said:

To add to what @stodge has suggested you have to factor in ex-tropical storms at this time of year.  And they could do one of two things, aid breakdown to unsettled, yes, or promote a longer term settled period through most of September.  

Was thinking of this as a likely possibility with such a strong high. The Tropical Storms rolling eastwards around the bottom of the high boosting it ?

[Frosty.]

Given all the various options on the table from the 12z output so far...., I think this from the ICON 12z stands out from the crowd, you could even call it iconic!
 

 

 

[MATTWOLVES 3]

6 minutes ago, Northwest NI said:

Was thinking of this as a likely possibility with such a strong high. The Tropical Storms rolling eastwards around the bottom of the high boosting it ?

There is a strong possibility that the Huge amount of ice melt over Greenland and strong blocking in the area is playing a role in the lack of Eastwards progression in those Tropical storms! That's recently been mentioned by Judah.

[MATTWOLVES 3]

As the nights grow longer,the High grows stronger...pretty much sums it up

[Northwest NI]

On 24/08/2021 at 19:42, MATTWOLVES said:

As the nights grow longer,the High grows stronger...pretty much sums it up

Could lead to very unsettled conditions in Iberia and @Tamara s part of the world ?

 

[Frosty.]

I’m liking the ECM 12z operational...and I think you will too!! ?  ....in a nutshell, this anticyclonic spell could stick around long time!  ? 

Edited August 24, 2021 by jon snow

[I remember Atlantic 252]

2 minutes ago, jon snow said:

I’m liking the ECM 12z operational...and I think you will too!! ?  

Not me! filthy mucky mess here, but yes good for western areas

[MATTWOLVES 3]

9 minutes ago, I remember Atlantic 252 said:

Not me! filthy mucky mess here, but yes good for western areas

The surface conditions will probably change and there will be daily variations...the forecast for the Midlands is an improving picture through the Bank Holiday according to the Midlands news this evening. You only live 20 or so miles up the road from me I believe. I do believe Stafford is part of the Shropshire constabulary! I don't think its going to be as bad as your making out mate.

[mb018538]

Looks like one of the longest stretches of high pressure sticking around that we’ve had in quite a while. Rotating and shifting around position wise, but going nowhere fast. Looks like being here as we go into September too.

[Methuselah]

Altogether, I'd say that the GFS is 'not rubbish'. Yes, winds are mostly coming from an easterly or northeasterly direction, but there's no cold air -- and T850s of 6-11C are not bad. A couple of weeks' dry and rather warm weather will do me fine!

    

    

    

And the GEFS temperature ensembles are NAE BAD!

   

Edited August 24, 2021 by Ed Stone

[Guest]

7 minutes ago, mb018538 said:

Looks like one of the longest stretches of high pressure sticking around that we’ve had in quite a while. Rotating and shifting around position wise, but going nowhere fast. Looks like being here as we go into September too.

Yup high pressure in control probably until about the 9th of Sept by my reckoning, maybe starting to swing towards a sightly more favourable orientation around month end as well but still plenty of cloud and clag for large parts of the population the next few days. It’s all well and good western Scotland reaching 27C but no one lives there - as much use as a snooze button on a smoke alarm  

[Northernlights]

7 minutes ago, Alderc said:

Yup high pressure in control probably until about the 9th of Sept by my reckoning, maybe starting to swing towards a sightly more favourable orientation around month end as well but still plenty of cloud and clag for large parts of the population the next few days. It’s all well and good western Scotland reaching 27C but no one lives there - as much use as a snooze button on a smoke alarm  

Put this in the Scottish Thread Earlier today   "Fabulous blue sky day now although barley grains still soft so no combining today . Just been speaking to my wintering sheep man in Skye and he was saying that they have had a better summer than 1976 and I had to say we are the same here. Not often the north of Scotland has the best summer weather.Currently 23c"

[Frosty.]

According to tonight’s ECM 12z ensemble mean, it looks anticyclonic not only for the rest of summer, but also into the start of autumn..how far into September will the settled spell last?...that’s above my pay grade so I will leave that to the professionals...where are you?...let’s be having you!!!! 

Edited August 24, 2021 by jon snow

[damianslaw]

I know it's not Dec- Feb but if it was, those who like cold would be very happy with the upcoming evolution. A cold front moving across the UK Thursday that then brings abone biting long drawn easterly/ north easterly flow. Heavy snow showers would be on order and max temps 0 or below.. alas it's late August and instead just a blanket of cloud and temps near average..

[Frosty.]

No complaints from me about the Gfs 0z operational, it’s anticyclonic throughout, just a slight less settled blip early September before a surge from the Azores and the very best charts are towards the end of the run!..there are plenty of warm days with sunny spells and temperatures into the low 20’s c but there are also some cloudier cooler spells with temps struggling in the mid / upper teens c...as for rainfall, there’s barely a trace for almost the entire run!....finally, as the nights slowly draw in and under clear skies, it could become rather chilly and there would also be a risk of mist / fog patches...erm, yeah, I think that covers it! ️ ? ?  

[Frosty.]

No complaints from me about the Gfs 0z operational, it’s anticyclonic throughout, just a slightly less settled blip early September before a surge from the Azores and the very best charts / conditions are towards the end of the run!..there are plenty of warm days with sunny spells and temperatures into the low 20’s c but there are also some cloudier cooler days with temps struggling in the mid / upper teens c...as for rainfall, there’s barely a trace for almost the entire run!....finally, as the nights slowly draw in and under clear skies, it could become rather chilly and there would also be a risk of mist / fog patches...erm, yeah, I think that covers it! ️ ? ?  

Edited August 25, 2021 by jon snow

[Frosty.]

It was such a great post I had to show it twice!...just kidding, damn duplication, hate it when that happens! ...needs fixing!!!!!!!!!!!!!

Anyway, enjoy the sunshine! 

[sheikhy]

Ukmo and ecm as you were!very very dry with high pressure all the way to the end!hopefully we have similar charts come november december time!

[Methuselah]

It looks as though, once the 'dip' is out of the way, T850s will recover quite nicely. Here's hoping! GEFS 00Z ensembles:

    

[minus10]

Nice 'dooable' weather...

 

[mb018538]

Spot the high pressure....no measurable rain for many in the next 10 days as high pressure refuses to budge.

Very quiet. Ireland in particular looks to be in for a tremendous spell of weather. West is best here, and ROI will really benefit from the position of the high. 



Atlantic basin is quite active already, and expected to remain active in September with very favourable development conditions. Always a curveball for forecasting.

A quick look at the ECM day 6 NH chart shows 2 tropical systems that have developed - one along the coast in Texas, and one just to the west of the Azores.

[mushymanrob]

Theres no change right through next week if this chart is to be believed. That high is anchored and is going nowhere fast. Western areas will really be having a great end to Summer/start to Autumn, but those of us who are prone to north sea cloud - which currently is a large swathe of England - my have one of the most boring periods of weather ever. Grey skies, with no guarantee that itll change. I suppose that as the high intensifies it might suppress cloud formation..

The only good thing is that itll be dry.