Model Output Discussion - Early Summer and Beyond

[Singularity]

The MJO has almost finished its trans-Pacific journey and AAM has peaked in the neutral range. This week it should fall and the model are showing the typical response pattern, despite ex-Alex complicating matters later in the week: Most unsettled and cool in the north, most settled in the south where dry and warm weather outweighs cool and wet.

Thereafter, a typical progression for a La Niña base state would be a further fall in AAM, leading to a southward shift in the polar jet with high pressure tending to locate west of the UK. This, it seems, extended modelling has been assuming… until today, perhaps.

There are emerging signs that the MJO might sufficiently have altered the eastern tropical Pacific sea surface temps to enable establishment of a standing wave there to compete with the La Nina one. If this comes to fruition, it will promote an unstable AAM profile - one featuring substantial rises and falls in AAM which mean it’s not always in the Nina-like stages. In that setup, the rises facilitate ridges over Western Europe which at times extend far north enough for the UK to get involved with hot weather - usually for a few days at a time.

The falls counter with cooler, sometimes unsettled spells (whether unsettled depends how far down AAM drops).

With warm SSTs around the UK this pattern could well give us an above normal CET & UK mean temp but with near to above average rainfall for most.

[chapmanslade]

2 hours ago, Alderc said:

Nope to storms and nope to any heat on the surface conditions. The ECM maintains a west or south westerly surface flow for all but a couple of hours and we don’t tap into the potential of the hot uppers, there’s also a lack of anything convective. 

Obviously a long way but remember June 2019 when the surface north easterly stopped us tapping into 25C uppers so can easily happen.

But the GFS 06z showed 29c for London next Monday. One run to another at a week away.

What is perhaps more pertinent is that there is very likely to be significant heat in France next weekend and there is a considerable chance that may spill north to the UK, with or without storms. 

It is far from 'utter dross' as you posted earlier, it is actually fascinating with all manor of potential outcomes.

 

[mushymanrob]

36 minutes ago, bluearmy said:

NOAA cpc charts never include 12z runs 

if tomorrows runs continue the theme of the 12z’s then expect the cpc 6/10 to back the upper trough west a bit more tomorrow 

 

They are a blend of the 06 GFS and the 00z ECM and Canadian..... id suggest thats more accurate then just the 12z GFS...

Time will tell.... but i really do hope you are right! Id prefer your suggested outlook to mine! lol..

[Frosty.]

There’s not much I can say about the Gfs 0z operational, so I will leave it to my best m8 Churchill!  

[Guest]

7 hours ago, chapmanslade said:

But the GFS 06z showed 29c for London next Monday. One run to another at a week away.

What is perhaps more pertinent is that there is very likely to be significant heat in France next weekend and there is a considerable chance that may spill north to the UK, with or without storms. 

It is far from 'utter dross' as you posted earlier, it is actually fascinating with all manor of potential outcomes.

 

Ah the mean the utter dross that’s transpired in this mornings 00Z gfs, which was exactly what it’s ensembles pointed to last night. 

[mb018538]

Overnight ECM update is poor too:

Week commencing 20th June - UK well and truly has the blues:



No real signs of anything remotely lasting and settled on the horizon at the moment. GFS turns into a bit of a horror show as early as day 11 and never recovers:

[bluearmy]

8 hours ago, mushymanrob said:

They are a blend of the 06 GFS and the 00z ECM and Canadian..... id suggest thats more accurate then just the 12z GFS...

Time will tell.... but i really do hope you are right! Id prefer your suggested outlook to mine! lol..

Rob, as you know, noaa cpc looks at gem, gfs and ecm (and blends ens and ops which fit the ens guidance) 

it uses 00z from the three models and any 06z gfs it likes 

My post yesterday merely referenced the 12z gefs as a variation on just using the eps.the eps were even less troughy.  NOAA cpc will not pick up a significant movement from the 12z suites. (Which isn’t necessarily a bad thing btw).

anyway, let’s see the ec 00z data before making any more comments 

At this time, my initial (form horse) post seems very reasonable ref the upcoming weekend when compared to what the nwp was actually showing. 

Edited June 7, 2022 by bluearmy

[sheikhy]

25 minutes ago, bluearmy said:

Rob, as you know, noaa cpc looks at gem, gfs and ecm (and blends ens and ops which fit the ens guidance) 

it uses 00z from the three models and any 06z gfs it likes 

My post yesterday merely referenced the 12z gefs as a variation on just using the eps.the eps were even less troughy.  NOAA cpc will not pick up a significant movement from the 12z suites. (Which isn’t necessarily a bad thing btw).

anyway, let’s see the ec 00z data before making any more comments 

At this time, my initial (form horse) post seems very reasonable ref the upcoming weekend when compared to what the nwp was actually showing. 

Ukmo looks like 12z ecm from yesterday!!00z ecm now drops the cut off low for the weekend so not as warm but still not a washout and more fresher with a northwest wind!!ecm 12z could bring it back again!!

[mb018538]

27 minutes ago, sheikhy said:

Ukmo looks like 12z ecm from yesterday!!00z ecm now drops the cut off low for the weekend so not as warm but still not a washout and more fresher with a northwest wind!!ecm 12z could bring it back again!!

ECM isn't a terrible run....ok it isn't overly warm or settled, but it least has a bit of mobility and things are moving. Nothing worse than low pressure that gets stuck. At least everything on this run moves through and it isn't a washout. Should even see a bit of sunshine.....who'd have thought!

[sheikhy]

20 minutes ago, mb018538 said:

ECM isn't a terrible run....ok it isn't overly warm or settled, but it least has a bit of mobility and things are moving. Nothing worse than low pressure that gets stuck. At least everything on this run moves through and it isn't a washout. Should even see a bit of sunshine.....who'd have thought!

Yup as i mentioned no washout!!!still plenty of sun and dry weather but not as warm as yesterdays 12z!after the recent crap i have endured i will take 00z ecm all day!!as i say the cut off low could be back on the 12z which will bring the heat with it hopefully as well!!

[mb018538]

The only area that suffers on the ECM run is the far NW corner of Scotland. Western areas wetter than the east (to be expected in a westerly flow), but most areas seeing no more than 30mm of rain over 10 days, which isn't too bad I guess.
Temperatures a little disappointing - mid to high teens for many, perhaps scraping 20/21c at times in the S/E/SE.

[Frosty.]

I agree the ECMWF 0z operational isn’t a particularly bad run, I would describe it as changeable with a trough / ridge / trough / ridge type set up, essentially, the far NW most affected by occasional bouts of wind and rain / showers , and more emphasis on drier bright / sunny spells further S / SE. ️ ? 

Edited June 7, 2022 by jon snow

[bluearmy]

11 hours ago, mushymanrob said:

But the NOAA anomalies continue their consistent prediction of low pressure to our near West.... Who will be proven more accurate? only time will tell...

I would expect noaa charts today to show good continuity from yesterday. The 00z suites are not progressing any 12z trends and if anything, the pendulum has swung back a little.  Hence my earlier comment that it’s not necessarily a bad thing that cpc doesn’t actually include 12z data. 

but the background trend that upper troughs are tending to affect less of the BI than modelling shows in the 7/10 day period remains true. 

[Cambrian]

Undulations in the Atlantic jet stream in keeping with the mobile pattern for the next few days like here on the 0z ECM operational run for day 2. 

 

The low sitting in the cradle at day 4, maintaining a changeable theme.

 

The jet stream fragments at the base of the trough going through the weekend, so that by day 6, the ridge pushes east through the gap. The Azores low is back in the picture by then too, pressing up against the high at its middle and serving to help nudge it north. 

 

Out to day 8, and the jet stream is trying to reconnect across the Atlantic but it’s much further north across the ocean than currently, giving us a gentle northwesterly flow by the middle of next week.

 

By day 10, it’s turned into more of a westerly, the jet stream hooking down into Europe, looking to form a low over the Adriatic Sea.
  

Only one run I know, but strikingly at the low end of the ensemble for pressure past day 8. All in all, the northward progression and slow but sure build of heights to our west and southwest looks a positive trend as we head into the second half of June. 

[Scorcher]

Always amusing how the harbingers of doom appear (two posters in particularly) every time there is a downturn in the output. Fair to say the GFS 00Z is a huge unsettled outlier in it's latter stages.

I really can't see a huge amount wrong with the ECM 00Z. Not an exciting run by any means but fairly average. And as others have alluded to, average at this time of year is pretty nice in general.

 

[Guest]

1 hour ago, Scorcher said:

Always amusing how the harbingers of doom appear (two posters in particularly) every time there is a downturn in the output. Fair to say the GFS 00Z is a huge unsettled outlier in it's latter stages.

I really can't see a huge amount wrong with the ECM 00Z. Not an exciting run by any means but fairly average. And as others have alluded to, average at this time of year is pretty nice in general.

 

It’s amazing how so many people appear to love massive hot outliers being posted that two weeks away and extremely unlikely. 

[mb018538]

There is still potential for a good improvement in the weather as we head out of June. AAM on the latest ECM run yesterday is almost off the scale low in the next fortnight. In a La Nina setting this isn't usually good news for the UK, which helps to explain the unsettled output on offer.
VP anom forecast shows the MJO moving significantly as we head towards the end of June. This massively spikes AAM upwards and should help the retracted Atlantic ridging start to push east again and promote more ridging in NW Europe where we currently see troughing. Keep your eyes peeled on this one.

[mushymanrob]

3 hours ago, bluearmy said:

I would expect noaa charts today to show good continuity from yesterday. The 00z suites are not progressing any 12z trends and if anything, the pendulum has swung back a little.  Hence my earlier comment that it’s not necessarily a bad thing that cpc doesn’t actually include 12z data. 

but the background trend that upper troughs are tending to affect less of the BI than modelling shows in the 7/10 day period remains true. 

But why are you so hung up on the 12z trends? are the 12z runs more accurate?..

Well im going on these and these alone, rightly or not, as most of the time they do spot more accurately than other suites the most likely emerging pattern in the 6-14 day timeframe . A couple of months ago i did a bit of research on how they had performed in the first few months of the year... and were 80-85% accurate, getting only 1 major change wrong.

These may be wrong this time, my forecast is based upon what i think they are predicting. As i see it, they are predicting a moderate/strong Southwesterly upper flow throughout the period June 12th - 20th. Theres troughing to our near West, ridging to our East, neither are particually strong  but the UK is slightly more under the troughs influence. That doesnt allow for much settled/ridge type conditions although transient ridges are likely. Id expect frontal systems, so unsettled or changeable.. mixed with brighter but showery conditions with the NW/SE split. Temperatures around average, so not bad, feeling muggy too. Id be surprised if these charts were far wrong, but it is possible.

 

[MP-R]

38 minutes ago, mb018538 said:

There is still potential for a good improvement in the weather as we head out of June. AAM on the latest ECM run yesterday is almost off the scale low in the next fortnight. In a La Nina setting this isn't usually good news for the UK, which helps to explain the unsettled output on offer.
VP anom forecast shows the MJO moving significantly as we head towards the end of June. This massively spikes AAM upwards and should help the retracted Atlantic ridging start to push east again and promote more ridging in NW Europe where we currently see troughing. Keep your eyes peeled on this one.

Gawd I hope so... we haven’t had any prolonged settled weather since April!

That said, the south doesn’t look ‘too’ bad unless we land another soaker low like Sunday. There doesn’t seem to be such an appetite for a plume today so perhaps not.

[Guest]

Absolutely nothing of interest in the GFS ensembles from the 06Z runs. All extremely meh nothing to suggest a settled spell with a run of sunny days. Still can’t get two on the trot! 
 

[bluearmy]

1 hour ago, mushymanrob said:

But why are you so hung up on the 12z trends? are the 12z runs more accurate?..
 

I’m not 

[chapmanslade]

3 hours ago, Scorcher said:

Always amusing how the harbingers of doom appear (two posters in particularly) every time there is a downturn in the output. Fair to say the GFS 00Z is a huge unsettled outlier in it's latter stages.

I really can't see a huge amount wrong with the ECM 00Z. Not an exciting run by any means but fairly average. And as others have alluded to, average at this time of year is pretty nice in general.

 

Indeed. Some would make you think we WERE in October already. Plenty of 20C plus days in the last 2 weeks here, currently 21.6C with every suggestion that the ex TS Alex will scoot up towards Iceland on Friday leaving us to pull in the very warm air off the continent. OK it will be warmest in the south but that is ALWAYS the case in most summers. Mid 20's entirely possible, but from that source there will always be the risk of thundery downpours.

We are having an entirely average spell of UK summer weather, not dross, not scorching, just average.

[chapmanslade]

30 minutes ago, Alderc said:

Absolutely nothing of interest in the GFS ensembles from the 06Z runs. All extremely meh nothing to suggest a settled spell with a run of sunny days. Still can’t get two on the trot! 
 

You had three on the trot last week!

[MATTWOLVES 3]

Wow we appear to be at that debate again where discussion of what models or data are most accurate.. to me to you...mines better than yours...mines bigger than yours...no its not

As far as I'm concerned all models for UK forecasting need too be taken with a huge pinch of salt...in both Winter and Summer...beyond 10 days and Mr climatological normal rears its ugly head.

To my eyes this weekend away from the NW part of the UK looks reasonably fine. That's not gonna cheer those further NW up...but hopefully things will improve for all with time. 

The guidance from the ECM oz suite shows the spread uncertainty again moving forward....with the op more optimistic for an improving picture...again I would say South of North Wales looks the best bet at this stage.

I spotted an unusual ball off fire in the sky just now...im rather bemused....what could it be! Answers on a postcard please..

Whatever the weather....enjoy life..

Edited June 7, 2022 by MATTWOLVES

[Guest]

55 minutes ago, chapmanslade said:

You had three on the trot last week!

Show me? We had one day with 13.5hrs which was the 3rd June. Not had another day with more than 10hrs since 28th May. 
 

Edited June 7, 2022 by Alderc