Model Output Discussion - Spring Has Sprung

[CoventryWeather]

 Howie Its not a terrible run though. Little wind, showers, thunderstorms, plenty of sunshine and it will feel warm. 

18/19 widely on there, adding the 1/2 degrees that the GFS struggles with. Can't see why people are complaining about it. 

[Dominic Carey]

 CoventryWeather i think people are complaining because they want weeks on end of +30 degree days and forgetting we’re surrounded by an ocean 

[Downburst]

Monday is probably the worst, although parts of eastern England might think Tuesday is worse. But in general not too bad a week.

Monday next ECM, organised fronts apparent

But rest of week in general more showery, picking this as good example Thursday.

The low sinks SE, with improving conditions if you like the showers to die down from the West or North West for next weekend.

[CoventryWeather]

Seems like we're heading towards a rather warm but thundery slack pattern for the final third of May. 

If you look at long range models it's a similar pattern for the rest of summer. Think plume events will be common this year. 

Edited May 10 by CoventryWeather

[Howie]

 CoventryWeather that is true. I think the past 9 months of grimness has got to me

[northwestsnow]

 Howie always tickles me when those in the SE moan, you really ought to spend 6 months up here in the Western Pennines - dreadful doesn't even do it justice  

I've noticed overnight less inclination to clear the troughing - I've already got one eye on the Euros , just over a month and I'd love a settled warm spell much better sat in garden watching the football ..

Of course 4 weeks is a long way out, but I'd be mega peeved if the troughing hasn't sodded off by then

[Rain All Night]

On 09/05/2024 at 11:49, Rain All Night said:

Hopefully everyone is quiet because you're all out enjoying the lovely weather we have now 

0z ensemble means, out to Fri 24 May (day 15)

From Saturday 18th onwards, you can see the real potential for warmth to come up from the southwest, and you can also see the danger lurking up near Iceland. It's impossible to say any more than that at this stage, but the foundations for hope are certainly there.

0z deterministic runs, on Thu 16 May (day 7)

Hopefully from Thursday onwards, the slackening surface pressure will create more opportunities for dry and sunny interludes. So it oughtn't be the case that the whole working week needs to be considered ruined.

0z ensemble means, out to Sat 25 May (day 15)

ECM is currently the most optimistic for next weekend. Beyond that, both ECM and GFS still offer hope of raised heights with a southwesterly tilt, while the GEM goes off-script and offers a horror show.

 

0z deterministic runs, on Fri 17 May (day 7)

I hope it's looking closer to UKMO than the other two by this point next week.

Edited May 10 by Rain All Night

[Mike Poole]

Further into summer, and the signal really isn’t clear - well not from two of the best seasonal models, anyway.

Here’s ECM height anomalies for June and July:

Here’s the same for UKMO GloSea6:

Difficult to see how they could be more opposite.  I’ll take ECM for June and UKMO for July, please.

[Don]

1 hour ago, northwestsnow said:

Of course 4 weeks is a long way out, but I'd be mega peeved if the troughing hasn't sodded off by then

A bit like you are during most winters?!  

[Alderc 2.0]

 Mike Poole and we’ll probably end up with the UKMO for June and ECM for July….

[Bats32]

Scandi High for the middle of May?!

 

https://twitter.com/judah47/status/1788930374795411676?t=noJhxcNjpApXdj6LO8LDMw&s=19

[Addicks Fan 1981]

 Bats32 to be fair I do trust him as he keeps close tabs on things.    

[Addicks Fan 1981]

 Alderc 2.0 the season maybe even better than you imply, depends if la niña kicks off, whether the QBO changes to a westerly regime and if there's changes to the PDO too.   

We need the weather in the tropics to be on our side for this summer, think that is the teleconnection we need to look out for.   

Also the zonal winds will play a part in how this summer behaves and whether they are positive or negative, things to look out for.   

[WYorksWeather]

UKV 03z from this morning going for 25C tomorrow, and 26C on Sunday.

Some eastern and northern areas of England plus parts of western Scotland may scrape another warm-ish day out of it on Monday.

Has to be said as well that Tuesday doesn't look horrendous temperature wise - we're not back to late April stuff here. Most areas should still be average or above with the chart below.

15z to come later for comparison.

[I remember Atlantic 252]

for Yorkshire! my area looks dreadful Mon and Tues

[Summer8906]

 Dominic Carey No they're complaining because they're sick of the endless cyclonic weather that has been dominant for 10.5 months so far, and likely to be dominant for eleven based on the current models!

I'd be quite happy with lower temperatures and moderate cloud amounts if only it could be dry three days out of every four, the sun shone from time to time, and pressure would remain at 1015mb or higher...

The models next week are just offering more of the same kind of synoptics that typified July, August, September, October, ... right up to the middle of April.

Edited May 10 by Summer8906

[Summer8906]

 WYorksWeather Temps around 4-5 degrees below normal here for two consecutive days, and with the wind from a "mild" direction - that can only mean one thing I suspect, two days of heavy cloud, and pretty persistent rain. But probably high dewpoint, so will likely feel clammy and unpleasant - not fresh. If the temps are barely going to get into the teens, I'd prefer a northerly! At least the air would feel clean and fresh.

 

 

Edited May 10 by Summer8906

[Azazel]

 Summer8906 nice of him to enlighten us that we are surrounded by an ocean. I thought we were landlocked in the middle of Europe. 

[WYorksWeather]

 I remember Atlantic 252 To be fair with the Tuesday chart that's all of East Anglia, Yorkshire, NW and NE England and parts of western/southern Scotland near to or above average. Admittedly my location, probably along with East Anglia, will have the best of it relative to average.

[Summer8906]

 WYorksWeather So does this translate to a waving front perhaps? I note there are two solid days of below average for many areas away from the E and NE, NW England, SW Scotland and parts of Somerset in the rain-shadow of Dartmoor. Suggests, perhaps, a persistent belt of rain in between, going nowhere?

Hope I'm wrong!

Edited May 10 by Summer8906

[WYorksWeather]

 Summer8906 UKV brings a pretty large rain in from the SW on Monday - probably responsible for the very suppressed temperatures across many southern and western areas away from the north:

On Tuesday, it's a bit more showery. This one is probably harder to call, but the best of any cloud breaks in the afternoon are predicted to be on a diagonal from East Anglia to western Scotland. Obviously far too early to say whether this will be right or not since showers are much harder to predict.

Overall it's really the timing of any cloud breaks that will determine temperatures. The air aloft will still be near to average temperature wise, so it's all about the surface conditions.

[Addicks Fan 1981]

Think @Mike Poole is correct about a NW/SE spilt developing and this op chart from the GFS in two weeks time is indicative of it.    

Edited May 10 by Addicks Fan 1981

[Summer8906]

 Addicks Fan 1981 Mind you, that looks to me like "wet everywhere, but especially in the northwest". I guess it is technically a NW/SE split, but won't be especially nice in the SE either. Certainly glad that utterly miserable chart is in FI!

Edited May 10 by Summer8906

[LetItSnow!]

Just having a quick look at the outlook for mid-month and seeing the trends for day 10. Starting with the GFS.

Pretty much an agreement that there will be a very unsettled spell around the 14th with an unusually deep area of low pressure centered just to our south-west. The low has nowhere to go so it generally weakens, pressure becomes slack and this could be ingredients for a showery period after perhaps some more general rain. My original thoughts of mid-May being a period of longer spells of rain, showers and some thunderstorms remains. The GFS wants to link this limpet low with an area of low pressure to the south of Iceland by Saturday the 18th. Details like that should be taken with a pinch of salt over a week away. Uppers generally remain around average so where the sun does come out it will feel pleasant in the May sunshine, otherwise nothing exceptional temperature-wise here.

The UKMO has a similar scene, a deep low on the 14th with generally weak pressure in the coming days with further bits of rain and showers around. The +5C uppers get mixed out which means if any longer spells of rain set up it could be pretty cool by day, otherwise unexceptional temperatures here. A potential pattern re-set at the end with a similar deep low around Iceland so perhaps a more north-westerly element may attempt to set up after the model parameters.

The GEM also starts with this quite deep low and also has it generally sit over the UK for the next few days. It also has some pretty cool uppers at times (0-5) meaning any showers or longer spells of rain may be quite cool, but sunny spells would be pleasant. However by day 10 there is build of pressure that may lead to an attempt to return to some warm and dry weather.

I don't think the ECM has updated yet but I'll throw its 00z output in the mix too. Same picture short term with the low meandering around the place with some showery conditions probably. Cooler uppers further south-west so once again, if longer spells of rain were in the mix perhaps some cool days but this won't be a problem if sunny spells occur. A slightly different end picture too with high pressure to our north-west and a gentle NE wind. This could bring a risk of cool temperatures, further showers and cloud, but details are far too out there to worry about.

My overall thoughts for mid-May and day 10.

Mid-May is looking like a step down from the warm and dry weather we've had the past couple of days. I don't think it's looking entirely horrific but changeable, nearer-normal temperatures (with perhaps regional variation) and with rain and showers around. It's probably not going to be a period that many people will remember as particularly amazing. Having said that, strong May sun and weak pressure aloft (and perhaps some cooler air mixed with the strong sun) may generate beefy showers, perhaps some thundery weather at times too. Indeed it's quite a typical May pattern. Further out is a bit harder to call. Perhaps low pressure to our north-west may introduce a northerly element but there is also signs that perhaps high pressure will return, though in what position is unclear.

[WYorksWeather]

We now have the 15z UKV update, and overall it does look like a slight upgrade on temperatures both for this weekend and for early next week.

Raw maxima of 25C tomorrow and 27C for Sunday.

On to Monday, and though much less warm there is increasing confidence now that eastern areas will stay fairly warm. Rain unlikely to arrive until late evening or overnight. Raw max of 21C.

Tuesday also looks better than it did on the UKV 03z, with a spot 20C.

Wednesday is appearing on here for the first time, and again we have a spot 20C.

A few people asking questions about the very poor temperatures for the time of year for Wales and SW / south-central England. On that, the main culprit seems to be below average 850hPa temperatures flirting with western areas, whilst the east stays average or possibly even somewhat above average.

Here are the afternoon 850s from Saturday to Wednesday:

Generally a greater risk of cold incursions in Wales and SW England than elsewhere, which might severely limit daytime temperatures if combined with cloud and rain. However, still time for these details to change.

Summary

I think overall this is an improvement compared to the previous update. A fair bit of rain around but if we're seeing 20C somewhere in the UK every day from Monday-Wednesday it can't be completely horrendous. I think a mixed early part of next week considering the UK as a whole, with the best of the weather in the east, is probably favoured. Some southern and western areas may have a very poor next few days though, unfortunately.