Model Output Discussion - Early Summer and Beyond

[Guest]

That is quite a dramatic change in the GFS mean in just 6hrs……seems like a lot to be resolved following next weekend. 

 

Edited May 16, 2022 by Alderc

[northwestsnow]

Models seem to be having all sorts of problems..

No consistency at all...

[mb018538]

1 hour ago, northwestsnow said:

Models seem to be having all sorts of problems..

No consistency at all...

We're in a bit of a transitional no mans land with the weather in the next week or so.

As you say @northwestsnow, no real consistency at all. Day 9 below  from ECM/GFS/GEM and they are all completely different.




Rainfall concentrated more in the west, with NW Scotland looking very wet with flooding a possibility



Tomorrow will be the warmest day of the year so far though. 26c or perhaps even 27c a possiblity:

  

[Penrith Snow]

Seems to me both GFS and ECM hint at high pressure to the west if the UK in 9 days time.

long way out of course but this current warm spell may not last beyond the weekend.

The weak northerly scenario seems likely as this has been a repeated pattern this spring.

If so expect more dry weather but a lot cooler 

Andy

[Earthshine]

Trending warmer again...

[summer blizzard]

Euro is not as bad but all bar GEM shift the pattern in the next few days. GFS6z was rather wonderful.

[Singularity]

The models are really struggling with the conundrum I put forward a couple of days ago. Will it be the quiet version of an AAM drop (high pressure close to the west, ECM style), or unsettled one (low pressure systems moving through, GFs style but probably with a less blocked overall pattern)?

Either way, the pattern should then tend gradually eastward toward early June, making for a drier trend, as we settle back into a low AAM regime. How warm will again depend on the NAO. It’s evolution via interaction with N Atlantic SSTs also seems to be giving the models a hard time at the moment.

[Singularity]

So, little change from both sides of the divide this evening - GFS still taking the unsettled route for next week while ECM takes a far more settled - though not entirely stable until day 9 - one.

Meanwhile UKM keeps bouncing between the two, having been with GFS last night but hanging out with ECM this afternoon. There are no allegiances among forecast models!

[Cambrian]

Unsurprisingly, the GFS operational did well for pinning down where we are today from 4 days ago

4 days back at 12z for today / 6z today for 12z today - 500hPa and jet stream charts

 
 

More interestingly perhaps, looking at the 12z operational run charts for day 8 from 4 days ago 

 

and comparing with those for day 4 from 12z today 

  

shows a reinstating of the jet stream across the Atlantic, and development of low pressure to our northwest rather than fleeting away to our north, a much more changeable looking chart with no mid-Atlantic ridge, and more rain on the way, the models seemingly quite labile at anything over 4-5 days at the moment.

The 12z ECM op closer to where it was 4 days ago but also in the process of correcting for low pressure deeper and closer to our northwest.

 

[mb018538]

ECM going for a high pressure reload at day 9/10 this morning. Doesn't really have full support at the moment, so a bit of a cherry pick.

NW/SE rainfall bias generally holding out for the next 10 days too. Staying on the warm-ish side for many with temps slightly above average.

 

[Frosty.]

Lovely end to the ECMWF 0z operational..with summer just around the corner by then!!! ️ ?  

[Cambrian]

The swallows had a devil of a time on their migration north to Europe this year, arriving very late, with changing weather patterns being proposed as a large part  of the problem. We had a couple of pairs arrive to the barns only yesterday, around a month later than usual, but their arrival is always heartwarming, a very special part of the spring. 

I think that they must have landed in Wales a few weeks ago, but have only come away from the crowd now in time to nest, which is a change in strategy I’ve not observed before, or maybe might just be due to their depleted numbers.

For nest building, they ideally need some mud, so a bit of rain, but not too unsettled - too windy is a real hazard around the eaves, muggy and rather warm at times, without becoming too hot too quickly is perfect for the proliferation of insects in the late spring, 

They will be eyeing the means of the 0z ECM and GFS ensembles with some satisfaction - 

the pressure charts showing a modest dip for a few days from day 5 to 9, but still no substantial build thereafter, for the rest of May at least…

 

nothing too unsettled with no real wind to speak of…

 

temperature plots showing the warmest day for a while is likely to be today, but staying largely in double figures with no extremes for the next couple of weeks and maybe a very slow but steady warm-up as we head towards the beginning of summer…

 

and plenty of scope for some of that all important precipitation during the next couple of weeks of nest building.

 

So looking like a good end to spring for our belatedly arrived friends, though for those hoping for a long spell of warm and dry weather this early on, at least for now, the current model outputs are maybe a little bit harder to swallow.

[Snowy L]

3 hours ago, jon snow said:

Lovely end to the ECMWF 0z operational..with summer just around the corner by then!!! ️ ?  

I swear that's been the day 10 chart for about 3 months now. The models never learn...

[Frosty.]

I’m liking the improvement in the GEFS 6z mean longer term..we lose the greens!? … ……(hey, just look at the charts I’ve looked at and you will see what I mean… I hope)!?  anyway, the Azores high / ridge gradually gains the ascendancy again following an essentially showery period.. wow..just in time for the start of the meteorological summer.. in fact!…go figure! ️  

 

Edited May 17, 2022 by jon snow

[Earthshine]

1 hour ago, Cambrian said:

The swallows had a devil of a time on their migration north to Europe this year, arriving very late, with changing weather patterns being proposed as a large part  of the problem. We had a couple of pairs arrive to the barns only yesterday, around a month later than usual, but their arrival is always heartwarming, a very special part of the spring. 

I think that they must have landed in Wales a few weeks ago, but have only come away from the crowd now in time to nest, which is a change in strategy I’ve not observed before, or maybe might just be due to their depleted numbers.

For nest building, they ideally need some mud, so a bit of rain, but not too unsettled - too windy is a real hazard around the eaves, muggy and rather warm at times, without becoming too hot too quickly is perfect for the proliferation of insects in the late spring, 

They will be eyeing the means of the 0z ECM and GFS ensembles with some satisfaction - 

the pressure charts showing a modest dip for a few days from day 5 to 9, but still no substantial build thereafter, for the rest of May at least…

 

nothing too unsettled with no real wind to speak of…

 

temperature plots showing the warmest day for a while is likely to be today, but staying largely in double figures with no extremes for the next couple of weeks and maybe a very slow but steady warm-up as we head towards the beginning of summer…

 

and plenty of scope for some of that all important precipitation during the next couple of weeks of nest building.

 

So looking like a good end to spring for our belatedly arrived friends, though for those hoping for a long spell of warm and dry weather this early on, at least for now, the current model outputs are maybe a little bit harder to swallow.

I wouldn't be so sure.  Indications that a blocked but +NAO around June time should bring something in the way of warmer and drier weather.

[damianslaw]

10 minutes ago, Earthshine said:

I wouldn't be so sure.  Indications that a blocked but +NAO around June time should bring something in the way of warmer and drier weather.

In the winter there was lots of talk of similarities with winter 91-92 which was a dry mild one. Spring 92 brought a very warm May and mild March, April near average.. similarities continue. June 92 was warm and quite dry, the summer then fell apart in July.. mmm some forecasts are going for a front loaded summer.. 

[Allseasons-Si]

Did anyone know that tropicaltidbits have expanded there EPS hours from 240-360?

here is a preview...

May 17 updates: ECMWF ensemble (EPS) plots have been significantly expanded, and NMME plots have returned.

EPS Model – 500mb Height Anomaly for Northern Hemisphere | Tropical Tidbits

WWW.TROPICALTIDBITS.COM

---

EPS model forecast of 500mb Height Anomaly for Northern Hemisphere

 

Edited May 17, 2022 by Allseasons-si

[Cambrian]

UK and Ireland nicely sandwiched between two shallow low pressure systems on the 12z ECM op at day 5, though the two lows are holding two very different air masses.

 

A cool northwesterly wins out for a while around day 7…

 

…before a transient high lands in for day 9, briefly advecting some warmth from the continent.

 

By day 10, the mid-Atlantic high giving it a real go to get established properly, but at its eastern edge, over the UK and Ireland, it’s getting squeezed between lows north and south, as cool and warm air continue to vie.

 

[damianslaw]

Rather dead in here today. 

[sheikhy]

8 hours ago, damianslaw said:

Rather dead in here today. 

Been dead for a few days now lol!!type of weather we about to have is a bit meh as well!!everyone has moved to the convective chat!!!

[mb018538]

29 minutes ago, sheikhy said:

Been dead for a few days now lol!!type of weather we about to have is a bit meh as well!!everyone has moved to the convective chat!!!

Mot much to discuss is there buddy...models a bit inconsistent still. Chance of something more settled/warmer again at the back end of next week, but a lot of water to pass under the bridge before that.




Main talking point today looks to be this potentially noteworthy bout of storms late tonight. One to certainly watch:

[Mike Poole]

26 minutes ago, mb018538 said:

Mot much to discuss is there buddy...models a bit inconsistent still. Chance of something more settled/warmer again at the back end of next week, but a lot of water to pass under the bridge before that.




Main talking point today looks to be this potentially noteworthy bout of storms late tonight. One to certainly watch:

Yes,  this is my frustration with the model output at the moment, it is totally inconsistent once beyond the reliable range and has been for some time.  With a trough modelled likely somewhere to our west (which is good), but not far enough away for many models to go the full high pressure over the UK, I expect an unsettled but warm spell with some opportunities for storms for the moment, and maybe a chance that the models will start to give a clearer picture as to what we can expect for June.  Much uncertainty still clouds the picture for now.

Edited May 18, 2022 by Mike Poole

[mountain shadow]

54 minutes ago, mb018538 said:

Mot much to discuss is there buddy...models a bit inconsistent still. Chance of something more settled/warmer again at the back end of next week.
 

Maybe towards the South and East. Looks pretty dire the further North and West with only brief drier interludes as the Atlantic remains mostly in control.

[Cambrian]

Aha! So that’s what they’ve done with the “heat at day 10” charts.

0z GFS op for 2 June - day 16 is the new day 10 ! Crafty.

 

Some time in June for real I reckon, there’s no great energy in the jet stream, it will be caught napping at some point. It’s already showing signs on several runs of slowly getting pushed north in the longer run - e.g. 0z GFS op day 10 / day 16, though currently in far fantasy land, this is a repeating pattern -

 

perhaps allowing our friend from the Azores to link up with the Northern European high for a more reliable slow build - 

get the high in first and the heat will follow. 

[mb018538]

Ensembles are all over the place. 20-25mb pressure spread in a weeks time just highlights the uncertainty.