Model Output Discussion - Autumn arrives

[sheikhy]

12 minutes ago, bluearmy said:

Eps clusters have one option from day 5 …… whilst I could be onboard with that being reasonable to day , beyond that it surely cannot be. 

we have days 3 to 6 on the mean with lower height anoms across the U.K. and away from that period we are in ‘no man’s land’. Of course, no man’s land in June is going to be more often than not decent for surface conditions. 

overall the drift is away from the poor outlook weeks 2 to 3 that we were looking at with a general rise in heights. Of course as was mentioned yesterday this won’t allow for incursions of a day or two of less pleasant conditions from time to time. 

Very good news!!!!keep em coming!!

[mb018538]

Day 8-15 ECM clusters....not the worst.

[StormChaseUK]

GFS wants to keep the low there for, well rest of year really lol

[Row w]

Hope not it can do one until it's a time of year it may be of use  if that's any

[Captain Shortwave]

The one thing to look for from the GFS is how it handles the next Atlantic low that will run over the Atlantic ridge at day 5, the previous runs simply zip this quickly eastwards and into the parent low over the UK. The Euros are slower and the low actually digs into the ridge, it is this action that allows heights to recover to our east/south east enough for conditions to turn drier and warmer.

[Nigelapplewhit4]

1 hour ago, StormChaseUK said:

GFS wants to keep the low there for, well rest of year really lol

Yes the models are showing that the low has no where to go other than directly over  the UK Meanwhile most of europe especially france and spain bask in summer sunshine under high pressure. . 

Edited June 22, 2022 by Nigelapplewhit4

[Nigelapplewhit4]

Very unsettled conditions on the way

[mountain shadow]

33 minutes ago, Nigelapplewhit4 said:

Very unsettled conditions on the way

Indeed, the next couple of weeks would appear utter dross, with rain likely every day across the North West, but even the South East getting the odd drenching too.

No sign of the trough moving anywhere soon.

[Frosty.]

Within the dung heap that is the GEFS 6z… ….there are some exceptions regarding early July…here they are! ️

 

[Guest]

1 hour ago, Nigelapplewhit4 said:

That precipitation chart is about as useful as a chocolate teapot.

The GFS continues to limpet the trough over the UK for an obscene amount of time, but even though it's FI is similarly dreadful, it is still FI and I am highly doubtful of such a prolonged continuation of troughing over the UK into July.

Happily, in such a setup, crumbs of comfort that we find in the GEFS longer term tend to be of greater value. 

[richie3846]

It's interesting to look further ahead, though there's hardly any talk about the situation that is developing over the weekend. I'm at a loss to why there is so much talk about fantasy models for 12 days ahead, when there is a lot of interest coming up which seems to be void here? 

 

I'm trying to make sense of it through the met office interpretation currently, they seemed to have toned down the impact of the change of air for the south, with temps looking slightly up for Friday to Tuesday, and some pleasant sunshine in-between the showers, temps now only a margin below average.

 

If any model watchers have anything to add about the weekend/early next week period, that would be amazing. 

[mb018538]

17 minutes ago, richie3846 said:

It's interesting to look further ahead, though there's hardly any talk about the situation that is developing over the weekend. I'm at a loss to why there is so much talk about fantasy models for 12 days ahead, when there is a lot of interest coming up which seems to be void here? 

 

I'm trying to make sense of it through the met office interpretation currently, they seemed to have toned down the impact of the change of air for the south, with temps looking slightly up for Friday to Tuesday, and some pleasant sunshine in-between the showers, temps now only a margin below average.

 

If any model watchers have anything to add about the weekend/early next week period, that would be amazing. 

 

Weekend and early next week is generally better the further S/E you are, away from the centre of the low pressure.
Temperatures close to average, suppressed in any areas that see longer spells of rainfall, perhaps a degree or two above in areas that stay dry and avoid the rain. Beyond this it depends what happens to the low stuck close by, too much uncertainty at the moment to make any predictions beyond here!

[Scott Ingham]

4 hours ago, bluearmy said:

Eps clusters have one option from day 5 …… whilst I could be onboard with that being reasonable to day , beyond that it surely cannot be. 

we have days 3 to 6 on the mean with lower height anoms across the U.K. and away from that period we are in ‘no man’s land’. Of course, no man’s land in June is going to be more often than not decent for surface conditions. 

overall the drift is away from the poor outlook weeks 2 to 3 that we were looking at with a general rise in heights. Of course as was mentioned yesterday this won’t allow for incursions of a day or two of less pleasant conditions from time to time. 

It wouldnt surprise me if we see a rinse and repeat pattern of plumes replaced by fresher unsettled air through the rest of july. In summer we see this a lot depending on the background AAM state

[JayAlmeida]

16 minutes ago, Scott Ingham said:

It wouldnt surprise me if we see a rinse and repeat pattern of plumes replaced by fresher unsettled air through the rest of july. In summer we see this a lot depending on the background AAM state

Wasn't AAM predicted to rapidly fall throughout the second half of June and thus the weather would be unsettled as a result? 

Apart from a few days here and there it has turned out to be the complete opposite (regional differences aside).

The background drivers seem very accurate at explaining weather after the fact rather than predicting it in advance.

Either that or the models themselves aren't very good at predicting the trajectories of the background drivers.

Edited June 22, 2022 by JayAlmeida

[Methuselah]

And here's this week's Met Office Ten-Day Trend. And it's hardly a washout! Doom-mongers wrong again? We'll see!

 

[seb]

13 minutes ago, Ed Stone said:

And here's this week's Met Office Ten-Day Trend. And it's hardly a washout! Doom-mongers wrong again? We'll see!

 

Who would have thought?!

The weekend washout reduced to a blip in most of the southern half of the UK (away from Wales) and the infinite trough bang over the UK sits to the West next week resulting in hardly any precipitation in the entire Eastern half of the country and temps in the SE are likely to exceed 25 degrees from Wednesday (i.e. well into the mid 20s).

[MP-R]

36 minutes ago, seb said:

Who would have thought?!

The weekend washout reduced to a blip in most of the southern half of the UK (away from Wales) and the infinite trough bang over the UK sits to the West next week resulting in hardly any precipitation in the entire Eastern half of the country and temps in the SE are likely to exceed 25 degrees from Wednesday (i.e. well into the mid 20s).

Many runs have shown this interspersed with a few 2007/2012 style runs. I’d certainly back that over a stationary trough over the UK for two weeks lol.

[mountain shadow]

39 minutes ago, seb said:

Who would have thought?!

The weekend washout reduced to a blip in most of the southern half of the UK (away from Wales) and the infinite trough bang over the UK sits to the West next week resulting in hardly any precipitation in the entire Eastern half of the country and temps in the SE are likely to exceed 25 degrees from Wednesday (i.e. well into the mid 20s).

I would have thought. Have been saying for days that there will be the usual North West/South East split with the North West remaining Autumnal and the South East a completely different world as ever.

[tight isobar]

30 minutes ago, mountain shadow said:

I would have thought. Have been saying for days that there will be the usual North West/South East split with the North West remaining Autumnal and the South East a completely different world as ever.

Yep, the split remains @ north/south. You can gladly take our heat here (for me anyway)!! It’s sweltering once again this afternoon .. however I’m still confident of a change of fortunes into July when things get more relaxed to the northern west of the hemisphere.. @ jet energy weakening-and perhaps more of the uk joining in summer proper

Edited June 22, 2022 by tight isobar

[Singularity]

2 hours ago, JayAlmeida said:

Wasn't AAM predicted to rapidly fall throughout the second half of June and thus the weather would be unsettled as a result? 

Apart from a few days here and there it has turned out to be the complete opposite (regional differences aside).

The background drivers seem very accurate at explaining weather after the fact rather than predicting it in advance.

Either that or the models themselves aren't very good at predicting the trajectories of the background drivers.

AAM has fallen a great deal, the trouble is some people correlate that directly with unsettled UK weather, when actually it also depends on how fast & far AAM falls & how much resistance to the usual response pattern (mid-Atlantic high & low over W or NW Europe) there is from the North Atlantic SST pattern (via influence on NAO) and Arctic Oscillation.

Lately, those two have resisted a great deal, favouring a +NAO setup with north-shifted jet stream. This has been enough to keep low pressure visits to the UK transient with finer interludes in between. Signs are, that may continue through late June, though the low looks to stick around a bit more this time as -AAM is at its peak.

Into early July, there remains expectation for  a CCKW or perhaps MJO event to take shape and transit the tropical Pacific. That will drive AAM upward & promote some longer spells of dry, warm or hot weather across Western Europe - but to what extent remains to be resolved, as AAM might only rise to near neutral which would not suggest a prolonged pattern shift.

[minus10]

2 hours ago, Ed Stone said:

And here's this week's Met Office Ten-Day Trend. And it's hardly a washout! Doom-mongers wrong again? We'll see!

 

Yes once again the east with very little rain (storms not withstanding) and the potential to be warm/very warm at times. W/E split...hmm where have we seen that before..?

Lovely summery day today...a touch warm for working outside though..be good if any storms that do occur tomorrow can give us some decent rain..please...

[Cambrian]

By day 6, on the 12z GFS operational run, the low pressure to the northwest elongates, troughing to the south, sending what is perhaps the most organised rain belt of the next week or so through Ireland and the UK. 

 

The fate of this band of rain as it moves through gives an emphatic illustration of the west / east split regarding rainfall. Giving Ireland a good soaking by 132h, the 6 hourly intervals show it into westernmost parts of the UK by 138h, intensification over Wales as it gets some lift from the mountains at 144h, but then it fragments, largely skirting around the Midlands at 150h, before generally fizzling out as it pulls away from a dry Kent. 25-40mm in some western parts, next to nothing in parts of the east.

    

Further north, next Tuesday looks to provide a full day of rain for southwest Scotland, while as shown by the 24 hour accumulated precipitation chart to 156h,

 

parts of northeast Scotland stay dry, the southwesterly supply also affording that part of the world the benefit of a Foehn effect, with a 9 degree difference across the Highlands, so perhaps more of a southwest / northeast split for Scotland. 

Edited June 22, 2022 by Cambrian

[richie3846]

11 minutes ago, Cambrian said:

By day 6, on the 12z GFS operational run, the low pressure to the northwest elongates, troughing to the south, sending what is perhaps the most organised rain belt of the next few days through Ireland and the UK. 

 

The fate of this band of rain as it moves through gives an emphatic illustration of the west / east split regarding rainfall. Giving Ireland a good soaking by 132h, the 6 hourly intervals show it into westernmost parts of the UK by 138h, intensification over Wales as it gets some lift from the mountains at 144h, but then it fragments, largely skirting around the Midlands at 150h, before generally fizzling out as it pulls away from a dry Kent. 25-40mm in some western parts, next to nothing in parts of the east.

    

Further north, next Tuesday looks to provide a full day of rain for southwest Scotland, while as shown by the 24 hour accumulated precipitation chart to 156h,

 

parts of northeast Scotland stay dry, the southwesterly supply also affording that part of the world the benefit of a Foehn effect, with a 9 degree difference across the Highlands, so perhaps more of a southwest / northeast split for Scotland. 

The met also made a big point about the west/east rain expected over a number of days, in their 10 day trend, highlighting the huge contrast. It seems that a number of models agree on this feature, the hills especially recieving high totals in the west, whilst the rest of us will get much less. 

[Cheshire Freeze]

22 minutes ago, richie3846 said:

The met also made a big point about the west/east rain expected over a number of days, in their 10 day trend, highlighting the huge contrast. It seems that a number of models agree on this feature, the hills especially recieving high totals in the west, whilst the rest of us will get much less. 

Really depends on spot totals, even in the east. At this time of year it's pretty much impossible to rule out torrential downpours with pressure sub-1020mb. I've seen many 'mainly dry' days with the cap punctured and localised 50mm falling.

Happened in August 2007 here. Fairly benign day but with a cell that developed in isolated fashion and dropped a couple of inches of hail in an hour period.

This was the the chart that day

Edited June 22, 2022 by CreweCold

[Methuselah]

36 minutes ago, Cambrian said:

By day 6, on the 12z GFS operational run, the low pressure to the northwest elongates, troughing to the south, sending what is perhaps the most organised rain belt of the next week or so through Ireland and the UK. 

 

The fate of this band of rain as it moves through gives an emphatic illustration of the west / east split regarding rainfall. Giving Ireland a good soaking by 132h, the 6 hourly intervals show it into westernmost parts of the UK by 138h, intensification over Wales as it gets some lift from the mountains at 144h, but then it fragments, largely skirting around the Midlands at 150h, before generally fizzling out as it pulls away from a dry Kent. 25-40mm in some western parts, next to nothing in parts of the east.

    

Further north, next Tuesday looks to provide a full day of rain for southwest Scotland, while as shown by the 24 hour accumulated precipitation chart to 156h,

 

parts of northeast Scotland stay dry, the southwesterly supply also affording that part of the world the benefit of a Foehn effect, with a 9 degree difference across the Highlands, so perhaps more of a southwest / northeast split for Scotland. 

Glenurquhart was a funny place to live weatherwise Cambrian: friends & family back in Englandshire would phone us to ask how we'd coped with all the snow (Eh, what snow?) or the deluge (eh, what deluge?). Methinks some folks just do not realise quite how effective Scotland's rain-shadow is: I believe that places like Tain, Evanton and Muir of Ord don't get very much more rain than Londinium does?

Edited June 22, 2022 by Ed Stone