Model Output Discussion - heading into April

[MATTWOLVES 3]

The trend is our friend it seems, the GFS mean is again showing the briefest of blips before pressure rises again.. I'm not even sure now if the SE will even experience a blip.. Its all good. 

[Guest]

The 12Z GFS post the 24th is a cool outlier, in fact bottom of the pile for nearly three straight days. Much better agreement from the ensembles, especially in the period 24-28th where the mean is around 10-11C in the south, most are grouped nicely between 8 & 13C!

[Mike Poole]

As we wait for the ECM, there is one thing I have noticed in today's 12z runs compared to yesterday's (unless there is something special in the near term, I don't tend to give the 0z runs more than a cursory glance).  Yesterday, and for a few runs previously, there was a signal, quite strong actually, to pull the high back west in the day 8 to day 10 period.  That has totally gone today from all the output.  

This is very significant, the pattern now being shown is the classic ridging from the Azores, breaking off to form separate highs over Scandi, jet stream north.  This will fuel the positive feedback loop with the SST anomaly, which is what lovers of heat and settled summer weather want.  The high retracting west, while still having influence on our weather, would have broken this feedback, so that is a significant shift from the models in favour of a decent start, and indeed first half of summer, I would suggest, in line with long range models.

Edited May 18, 2020 by Mike Poole

[Frosty.]

I’m very happy with the GEFS 12z mean because it shows only a very brief flirtation / glancing blow from the Atlantic to the NW before high pressure flexes it’s muscles again and for southern u k in particular it’s looking like a largely fine and warm, sometimes very warm outlook with the Azores being our friend rather than the fiend it usually is during winter!..in the meantime, enjoy the building warmth / heat and increasing sunshine, high 20’s c expected for the s and especially se on wed but then watch out for potentially very severe thunderstorms for the se / east anglia on Thursday.

Edited May 18, 2020 by JON SNOW

[kold weather]

33 minutes ago, Mike Poole said:

This is very significant, the pattern now being shown is the classic ridging from the Azores, breaking off to form separate highs over Scandi, jet stream north.  This will fuel the positive feedback loop with the SST anomaly, which is what lovers of heat and settled summer weather want.  The high retracting west, while still having influence on our weather, would have broken this feedback, so that is a significant shift from the models in favour of a decent start, and indeed first half of summer, I would suggest, in line with long range models.

That pattern crops up quite often in hot 1st halves of summer, it occurred in June/July 2006 for example multiple times, and to an extent in summer of 2018 as well. Not saying this summer will end up like those as it looks a little too mobile compared to those two thus far, however its an interesting trend to note.

[MATTWOLVES 3]

Ecm looking good come the Weekend again. 

Its looking tasty.. Ohh yess

Edited May 18, 2020 by Mattwolves

[Zak M]

ECM is good at 168

[mb018538]

Fantastic ECM day 7/8. Turning very warm/hot with a better feed of warmer air. 850s up to 13c in the south.

[Mike Poole]

ECM T192, just look at that swathe of pressure >1030 hPa

Edited May 18, 2020 by Mike Poole

[Guest]

Incredible ECM192, 1025mb high pressure from Eastern Kazakhstan, through Europe and then stretching across the Atlantic to eastern Canada! Blocky mcblock central....

[Mike Poole]

The day the models sussed the pattern?  It looks like it to me.  

[Man With Beard]

ECM quickly back into the heat next week, raw temps of 27C again by Tuesday, so another pop at 30C possibly coming up? 

[Mike Poole]

JMA joining the party, T192:

The end of that run will be interesting, shame it doesn't come out until near midnight!  And don't forget, there are positive corrections to all of this still possible, there was one today compared to yesterday, as I mentioned earlier.  Everything on the 12z suite has been a step towards rather than away from proper summer conditions taking hold for some considerable time.  Great!

[mb018538]

8 minutes ago, Mike Poole said:

JMA joining the party, T192:

The end of that run will be interesting, shame it doesn't come out until near midnight!  And don't forget, there are positive corrections to all of this still possible, there was one today compared to yesterday, as I mentioned earlier.  Everything on the 12z suite has been a step towards rather than away from proper summer conditions taking hold for some considerable time.  Great!

Looks great, no doubt about that. I think there is the possibility of everything backing west slightly towards the end of next week as pressure starts to fall, but until then it’s another good stretch of summery weather. This is turning into one of the best 3 month spring periods I can remember.....can’t really remember such a dry and consistently sunny one.

[Methuselah]

GEFS 12Z ensembles looking good; even with op on the cooler side, I'm sure we can all cope with one day with uppers of 0C?

    

And the ECM:   

[Nath]

Looking like summer weather is here to stay for quite a while.  Great news as with lockdowns easing, this is the best weather to help kill the virus!

[Allseasons-Si]

49 minutes ago, Mike Poole said:

ECM T192, just look at that swathe of pressure >1030 hPa

Yep and i also noticed a welcome warm smile from the ECM this evening

great models all around today,turn up the heat..

 

[Mike Poole]

ECM mean T192 and T240:

Lovely sausage shaped 1030 region at T192, position slips on T240, but on the strength of today's op output compared to yesterday's, I expect this might change.  

 

[MATTWOLVES 3]

Thanks at @Mike Poole stay safe and enjoy the upcoming weather, and that's goes for all of you gr8 netweather posters, always such an enthralling read.. ECM mean looks good, we are getting used to this now, long may it continue... I've posted the charts from day 7 onwards from both the 0z and 12z runs.. Basically spot the difference perhaps the high not as backed as far West on the 12s..my eyes are burning a little so I may have missed it... Gr8 stuff folks.. Enjoy your evening, and enjoy the upcoming fine spell. 

Edited May 18, 2020 by MATT☀️

[Kentspur]

Seeing as the ECM ensemble mean for London is showing a continuation of summer like conditions throughout the rest of the month, I was wondering what the record is for the amount of May days with somewhere recording temps in the 20s in the UK? As except for maybe this Saturday every other day looks to remain 20c+ for many of us. It very much feels like June/ July already down here with the high UV levels the same as late July

Edited May 18, 2020 by Kentspur

[damianslaw]

19 minutes ago, Kentspur said:

Seeing as the ECM ensemble mean for London is showing a continuation of summer like conditions throughout the rest of the month, I was wondering what the record is for the amount of May days with somewhere recording temps in the 20s in the UK? As except for maybe this Saturday every other day looks to remain 20c+ for many of us. It very much feels like June/ July already down here with the high UV levels the same as late July

Suspect Mays of 1992 and 2018 will have produced many days of 20 degree tops. Last week was preety cool, and I suspect there were days when 20 degrees wasn't breached.

[damianslaw]

Models showing a continuation of the very dry sunny and mostly warm conditions in the south and east at least for the foreseeable, in the north and west there has been a change recently to wetter conditions, and only Wednesday looks a reliably decent warm sunny day further north. Thursday-Saturday sees an atlantic low development - unusually deep for the time of year, strong winds and rain in the north and west Friday - not very May like.

Through the Bank Holiday weekend high pressure from the azores will be the main influential player, so a return to drier sunny and warm weather for all again, possibly becoming very warm in the SE early next week.

Latter stages of May, nothing too untoward shown from the models today, although GFS wants to bring in cooler atlantic air as the azores high backs west, we saw this shown in other models yesterday, today they show the high being more robust. The position of the azores high is crucial, will it stay in situ, build further east, build further west, even stevens on all three happening I think.

[Scorcher]

40 minutes ago, damianslaw said:

Models showing a continuation of the very dry sunny and mostly warm conditions in the south and east at least for the foreseeable, in the north and west there has been a change recently to wetter conditions, and only Wednesday looks a reliably decent warm sunny day further north. Thursday-Saturday sees an atlantic low development - unusually deep for the time of year, strong winds and rain in the north and west Friday - not very May like.

Have you had a lot of rain in the Lake District then?

We have only had 6mm near Manchester Airport in the whole of May so far and it looks unlikely we will add to that in the foreseeable future.

It has been rather cloudy here for the past few days but no rain to speak of.

Brighter from tomorrow for much of NW England I think.

Edited May 18, 2020 by Scorcher

[Fourty Point Three Degrees]

Lots of positive action within the models lately especially ECM. Looks like May could finish up being another dry month. Reminds me of May 2018 which was HP dominated, although synoptics were completely different then im wondering what it would take to shift into a pattern just like that in 2018?? 

[Premiere Neige]

2 hours ago, mb018538 said:

Looks great, no doubt about that. I think there is the possibility of everything backing west slightly towards the end of next week as pressure starts to fall, but until then it’s another good stretch of summery weather. This is turning into one of the best 3 month spring periods I can remember.....can’t really remember such a dry and consistently sunny one.

2018?