Model Output Discussion - Spring Has Sprung

[danm]

 ANYWEATHER Days 7 and 8 on the models this morning. 

[ANYWEATHER]

 danm yes. Day 7and 8 , unreliable time frames. Especially given the high level of Shanon Entropy.

[danm]

 ANYWEATHER no one said it was guaranteed? Just commenting on what the models are showing. 

[Derecho]

 ANYWEATHER To be fair this bank holiday weekend always looked dubious whereas the signal on that EC mean for next week is pretty strong.

Although it does seem if the weather gods can find a way of making things underwhelming this year, they will...

[Rain All Night]

12 hours ago, Rain All Night said:

12z deterministic runs, out to Sun 5 May (day 7) - bank holiday Sunday

It's OK, ICON is the only model that matters  #atleastitwillbemild

12z ensemble means, out to Mon 13 May (day 15)

GEFS perhaps not quite as keen as ECM to send the high packing over the Atlantic towards mid-May?

0z deterministic runs, out to Mon 6 May (day 7) - bank holiday Monday

Warmer air arrives from Thursday, and then I can't call what happens over the weekend - it won't be ECM's previously-suggested anticyclone, but there are some options here that aren't too bad, particularly UKMO.

0z ensemble means, out to Tue 14 May (day 15)

ECM 9th May  - only shame is it's not a Saturday!

The high still seems to retrogress slowly from then on...

Edited April 29 by Rain All Night

[northwestsnow]

Exeter very unsure about the bank holiday weekend.

I do hope it doesn't go wrong again, there is the possibility of westerly winds and spells of rain spreading in from the west .

Perhaps my 'If it can go wrong it will ' post the other day when EC was looking superb will prove accurate ..

 

[Alderc 2.0]

 northwestsnow  not surprising the forecasting has gone to sh17. 

[midlandsun]

Looked at the forecast for the weekend this morning, 20 degrees for Saturday, look 2 hours later and it's now 11 degrees and rain. You have to laugh or you will bawl.

[northwestsnow]

 midlandsun

12z runs will be critical,one things for sure if it's 11 degrees and rain EC can sling it's hook.

[Howie]

Yeah the weekend is a loss

[danm]

The weekend is looking unsettled on the GFS, but Monday afternoon onwards again showing a very decent build of high pressure across the country:

Edited April 29 by danm

[In Absence of True Seasons]

 midlandsun It is quite baffling how it can change so drastically in such a short span of time. Gone from 19c and mostly sunny to 15c and showers in my area, as of today. Who knows, might be different again tomorrow.

[Addicks Fan 1981]

 northwestsnow think we can't trust rogue op charts, we have to buy time to do more of a deep dive if you see what I mean. 

The jet stream will migrate further north, and it wouldn't take much for it to shift north either.   

If anything I think we need the jet stream charts to return on here as they are probably of great clout of the goings on.   

[ANYWEATHER]

Looking at this range for the  Bank holiday, it don't look too good! Hopefully it won't be as cool and potentially wet as models show. 

[Daniel*]

ECM used to be quite convincingly best performing model unsure it is anymore..

From this to that quite shocking , still optimism for a noticeable improvement next week but it’s never easy.

[Alderc 2.0]

 danm as much use a chocolate teapot for those wanting to get out and enjoy the bank holiday weekend - not that I can lol…

[Alderc 2.0]

 Daniel* It’s had an absolute howler…..worse still is the Met Office will get a right bashing given they indicated a settling down into the BH Weekend, unfortunately their credibility with the general public is rock bottom.  

[Sherry]

There was no cross model agreement for bank holiday weekend? I don’t understand why people go by just one model! Unless there is cross model agreement then it’s pretty much no man’s land! This coming weekend may have looked good on ECM but GFS didn’t wanna take interest, hence the uncertainty, so why people then moan is beyond me! There is more cross model agreement for things to improve next week, which has been showing on more than just 1 model 

[danm]

 Alderc 2.0 yep but this weekend was never banked as one with good weather? It was always looking iffy. Next week has been showing for some time now settling down. Hopefully it does. 

[Daniel*]

5 minutes ago, Sherry said:

There was no cross model agreement for bank holiday weekend?

Well actually GFS was initially more the odd one and it proved right. There was decent representation for a warmer/settled long weekend outcome in EPS, it wasn’t just coming from det.

It has gone from this to this for Saturday 

[stodge]

Evening all

The evening's 12Z output shows the trough staying close to the south this week and it's only from just after the Bank Holiday (Tuesday - Wednesday next week) we begin to see the initial push of HP from the south west which crosses the British Isles and re-enforces the weak heights to the north and north east.

It's hardly a raging 1060MB Scandinavian anticyclone but it's enough with a quiet Atlantic to settle things nicely into the middle and latter parts of next week. With LP over Europe I suppose there's a risk of showers for the south and especially the Channel Islands but for north and especially north western parts it looks promising.

[Addicks Fan 1981]

 Daniel* it'll be very interesting how the NOAA anomolies go this evening, it's times like this where the teleconnections posters are needed.   Also as I've mentioned about the jet stream is it needs to be in a better position and we need to be on the warmer side of it.    

I also believe that the east QBO is peaking and will start trending towards neutral values soon, there is definitely easterlies blowing across the troposphere as things stand hence why our upper air isotherms aren't that great.   

Also think further afield will be a potential niña delay or it may not happen at all according to new CFS members and that may also do our atmosphere a favour.    

[Frigid]

 Daniel* Damn, a 10C drop for the 5th May. Best to not look beyond 5 days at this point, the models are definitely struggling atm. Still, it's likely to get much warmer than what we've seen recently.  

[WYorksWeather]

Evening all. Worth a quick update of the current situation with North Atlantic sea surface temperatures. As we're all aware it's the time of the year now when SSTs are very much beginning their annual climb in earnest. Here is the position from today's 00z ECM, at days 0, 5, 10 and 15.

You can see the annual climb most clearly by looking at the brown area above 22C. From being limited to the far left corner of the chart at around 30 degrees north at the moment you see it predicted to spread northwards. More subtly around the UK we see SSTs rising significantly, with only eastern coastal areas of northern England and Scotland below 10C by mid-month, and 12-13C near the south coast.

Of course, this is pretty meaningless without context, which is where the anomaly view comes in. Here is the anomaly view of the same data at days 0, 5, 10 and 15.

 

At day 0 we see some slightly warmer than average areas around the Azores and Iberian / west African coasts as has generally been the case for a while, and some warm anomalies also directly around the UK, particularly to the south off the near continent.

However, it is a complete transformation by day 15. Extraordinary to see really - an incredible extent of warmth around the whole of the UK, and a large positive anomaly from here to the Azores. Very striking.

Summary

In short, the upshot of the current and upcoming pattern seems to be likely to induce strong early warming of the North Atlantic. The result will likely be much less pronounced moderation of warm airmasses from the south than we'd normally expect at this time of year. It is also likely the case that overnight lows will be elevated.

This is already borne out by model output - latest GFS output for the London area, for example, has temperatures remaining above 10C by night almost every day for the next two weeks (some nights with lows of 12-13C), which even by 1991-2020 averages is extremely mild for overnight lows in spring. For early to mid May 7-8C would typically be expected on 1991-2020.

 

[Man With Beard]

I'm well aware this is super FI at the moment, but this has, at last, awoken me from my boredom at the weather so far in 2024 - a proper, meaty summer plume