Model output discussion 14/04/18

[damianslaw]

Would like some thoughts on when we might see a more significant pattern change - given we've been in a lengthy protracted non-atlantic spell for 2 months solid now, with only temporary blips. Seems to be some feedback mechanisms at place. The current synoptics are highly abnormal, with heights just not going anywhere it seems, another week of anticylonic weather ahead, and no rain for many, then the azores high ridging north east.  

Would like some seasonal forecasters to provide an explanation of why the jet seems so locked to our north and behaving in such a way at present.

This current spell is excellent, but if it continues for some time longer, it will begin to outstay its welcome - mother nature will recover, but persistant heat and no rain will takes its toll eventually.

[Frosty.]

Cracking Ecm 12z ensemble mean tonight..no end in sight to this lovely pattern, indeed, another high pressure is set to build in even more strongly towards the end of next week and intensify so apart from a few isolated storms breaking out for the s / sw most of the uk stays dry, very warm / hot and sunny for the foreseeable future..enjoy, summer in the uk doesn't really get better than this...Craig's impressed too!

 

[Willsy]

16 minutes ago, damianslaw said:

Would like some thoughts on when we might see a more significant pattern change - given we've been in a lengthy protracted non-atlantic spell for 2 months solid now, with only temporary blips. Seems to be some feedback mechanisms at place. The current synoptics are highly abnormal, with heights just not going anywhere it seems, another week of anticylonic weather ahead, and no rain for many, then the azores high ridging north east.  

Would like some seasonal forecasters to provide an explanation of why the jet seems so locked to our north and behaving in such a way at present.

This current spell is excellent, but if it continues for some time longer, it will begin to outstay its welcome - mother nature will recover, but persistant heat and no rain will takes its toll eventually.

I think it may be to do with the ssw back in February which smashed the pv to bits displaceing the jet stream making it very amplified and it’s still having a great effect on our weather 

[damianslaw]

15 minutes ago, Willsy said:

I think it may be to do with the ssw back in February which smashed the pv to bits displaceing the jet stream making it very amplified and it’s still having a great effect on our weather 

Yes that event certainly brought a marked shift in the position and strength of the jet since, we've seen easterly airstream take hold for much of the time. Lot of other factors could be at play, the cold SSTs to our NW over the atlantic and warmer SST values around UK shores could be helping to aid anticylonic/ridge development, AAM another factor or tropical forcing which seems to have been favourable to a warmer drier theme over the UK in recent weeks, low sunspot activity another factor, moving out of la Nina background to a more neutral heading towards El Nino set up. In many recent years the background players have been at odds, and not aligned either to create a sustained very unsettled summer or neither a pronounced lengthy settled spell of weather over the summer months and I include May and Sept in that category. Summers such as 2007 and 2012 did bring a persistant similar set up i.e an unsettled one, conversely 1995 and 2003 and 2006 brought a predominantly settled warm period. This year the signals seem to have aligned in a way that is delivering a persistant spell of similiar weather - a settled theme overall.

I would like to hear views about the second half of the summer though - it would be unprecedented I think to see a repeat of the mid May to late June period occur in mid July - late August, not even 1976 quite managed that. Incidentally both 1976 and 1995 came crashing down in very wet cool Septembers..

[Cheshire Freeze]

27 minutes ago, damianslaw said:

Yes that event certainly brought a marked shift in the position and strength of the jet since, we've seen easterly airstream take hold for much of the time. Lot of other factors could be at play, the cold SSTs to our NW over the atlantic and warmer SST values around UK shores could be helping to aid anticylonic/ridge development, AAM another factor or tropical forcing which seems to have been favourable to a warmer drier theme over the UK in recent weeks, low sunspot activity another factor, moving out of la Nina background to a more neutral heading towards El Nino set up. In many recent years the background players have been at odds, and not aligned either to create a sustained very unsettled summer or neither a pronounced lengthy settled spell of weather over the summer months and I include May and Sept in that category. Summers such as 2007 and 2012 did bring a persistant similar set up i.e an unsettled one, conversely 1995 and 2003 and 2006 brought a predominantly settled warm period. This year the signals seem to have aligned in a way that is delivering a persistant spell of similiar weather - a settled theme overall.

I would like to hear views about the second half of the summer though - it would be unprecedented I think to see a repeat of the mid May to late June period occur in mid July - late August, not even 1976 quite managed that. Incidentally both 1976 and 1995 came crashing down in very wet cool Septembers..

History has shown that indeed, once it breaks, it usually breaks in style... Just as you have alluded to. 

[EllyTech]

45 minutes ago, damianslaw said:

Yes that event certainly brought a marked shift in the position and strength of the jet since, we've seen easterly airstream take hold for much of the time. Lot of other factors could be at play, the cold SSTs to our NW over the atlantic and warmer SST values around UK shores could be helping to aid anticylonic/ridge development, AAM another factor or tropical forcing which seems to have been favourable to a warmer drier theme over the UK in recent weeks, low sunspot activity another factor, moving out of la Nina background to a more neutral heading towards El Nino set up. In many recent years the background players have been at odds, and not aligned either to create a sustained very unsettled summer or neither a pronounced lengthy settled spell of weather over the summer months and I include May and Sept in that category. Summers such as 2007 and 2012 did bring a persistant similar set up i.e an unsettled one, conversely 1995 and 2003 and 2006 brought a predominantly settled warm period. This year the signals seem to have aligned in a way that is delivering a persistant spell of similiar weather - a settled theme overall.

I would like to hear views about the second half of the summer though - it would be unprecedented I think to see a repeat of the mid May to late June period occur in mid July - late August, not even 1976 quite managed that. Incidentally both 1976 and 1995 came crashing down in very wet cool Septembers..

We are not in a serious drought as we were in '76. It was the drought that really was the outstanding feature of that Summer. However, we still have a 25 consecutive day heatwave to achieve, to match '76. 15 of those days with temps over 30C from June to July. 

[Weather-history]

7 hours ago, damianslaw said:

 

I would like to hear views about the second half of the summer though - it would be unprecedented I think to see a repeat of the mid May to late June period occur in mid July - late August, not even 1976 quite managed that. Incidentally both 1976 and 1995 came crashing down in very wet cool Septembers..

Has happened before.

1959 is a famous one, that summer was followed by a record breakingly dry September with heat still in early October.

 

 

[Weather-history]

Looking at the charts, I think some places are going to have their best first half to summer since 1976

[I remember Atlantic 252]

2 minutes ago, Weather-history said:

Looking at the charts, I think some places are going to have their best first half to summer since 1976

but can we get a decent August? Atlantic low pressure dominated month, not usually a summer month for Scotland and Ireland, more autumn

[mb018538]

Not much change this morning - ECM still looking wonderful for more summery weather. 

[shaky]

Another morning and another set of runs which pretty much keep the dry hot weather throughout!ukmo lookss a beast at 144 hours with the high right over the uk and maybe pushing eastwards!!

[northwestsnow]

Tremendous EC again this morning.

As Kevin mentioned, the best first half of summer here since 76 if these charts verify, EC pretty much would ensure a hot 1st half of July to go with the lovely may and june round these parts.

It cant go on forever but i must admit its quite surreal to wake to crystal blue skies every morning.

[Methuselah]

9 hours ago, damianslaw said:

Would like some thoughts on when we might see a more significant pattern change - given we've been in a lengthy protracted non-atlantic spell for 2 months solid now, with only temporary blips. Seems to be some feedback mechanisms at place. The current synoptics are highly abnormal, with heights just not going anywhere it seems, another week of anticylonic weather ahead, and no rain for many, then the azores high ridging north east.  

Would like some seasonal forecasters to provide an explanation of why the jet seems so locked to our north and behaving in such a way at present.

This current spell is excellent, but if it continues for some time longer, it will begin to outstay its welcome - mother nature will recover, but persistant heat and no rain will takes its toll eventually.

I keep thinking of the old cliche about how much effort it takes to put a loaded oil-tanker into reverse...it's going to take something a great deal of momentum to majorly change the current pattern, I believe? Perhaps we'll even need wait for the polar vortex to start reforming. Who knows? I only know that I don't!

[Jonathan Rhodri Roberts]

Thundery showers in the SW today and GFS suggests more to come on Wed & Thur too with high CAPE. That high pressure is a bit too far away from southern England which seems to be allowing the thundery lows in. Perhaps we haven't picked the best week to tour around Devon 

[ChezWeather]

ECM at 240

That high will take some shifting 

[ancientsolar]

Today was the day that the weather was going to break down, but here I am ... now plagued with humidity nearing that of August last year in Valencia! 
Watching the GFS charts coming through slowly.. ~ slowly feeling like NW France will get storms for days and we'll get the cloudy humidity.. in the SWUK
 

[Mike Poole]

So as we enter the first minor wobble of this hot spell, how do the models see the way forward?  It's not a breakdown.  It looks like a slack pressure regime will be in place over the next few days, so chances of thunderstorms, with a build back of the high by the end of the week. ICON here at T144 and T180, I'll take that!

Other models to follow...

Edit, and the UKMO about as good as is possible, here T144:

Edited July 1, 2018 by Mike Poole

[Frosty.]

Really great ukmo 12z..the heat, the sunshine set to go on and on..and on..lovely stuff..let Iceland have all the atlantic filth! 

Edited July 1, 2018 by Frosty.

[ancientsolar]

Next Saturday GFS, looks it will be pushing temperatures widely 30 and locally 33-35... Wow if that pulls off.. 




and buy Sunday we could be looking at mid 20s at 6am!


Edit ~ 
Could next Sunday be our first best chance of beating the UK heat record? 

Edited July 1, 2018 by ancientsolar

[SizzlingHeat]

6 minutes ago, ancientsolar said:

Next Saturday GFS, looks it will be pushing temperatures widely 30 and locally 33-35... Wow if that pulls off.. 




and buy Sunday we could be looking at mid 20s at 6am!


Edit ~ 
Could next Sunday be our first best chance of beating the UK heat record? 

That's wrong. The temps for next Saturday are 25-29c on GFS. Not sure where you see temps of mid thirties on that chart? Not with uppers of 12c

 

Edit- Sunday showing high twenties. Would get to between 30-32c thought with the GFS underestimation of temps.

However, mid to high thirties are NOT on the cards for next weekend. I emphasise absolutely not. Nowhere near sufficient conditions for that level of heat. Very misleading post for those with little knowledge.

Edited July 1, 2018 by SizzlingHeat

[Mike Poole]

GFS run is interesting not because it's different in the medium term, but the feature west of Portugal may make a difference later on, it's stronger than on the other model runs.  Here at T186:

That low will pump up heat, where we go from here, if indeed 'here' happens will be interesting.

Otherwise great for UK heat! 

Edited July 1, 2018 by Mike Poole

[ancientsolar]

3 minutes ago, SizzlingHeat said:

That's wrong. The temps for next Saturday are 25-29c on GFS. Not sure where you see temps of mid thirties on that chart? Not with uppers of 12c

Well, looking at the same charts last week, and comparing to next weeks.. and seeing that GFS undercooks alot of temperature, i'm calling Widely 31-35C

[mb018538]

I think the 500b heights may be misleading you there - the darker reds don’t just translate to more heat sadly. It’ll still be very warm though!

[mb018538]

1 minute ago, ancientsolar said:

Well, looking at the same charts last week, and comparing to next weeks.. and seeing that GFS undercooks alot of temperature, i'm calling Widely 31-35C

It won’t be that high - Synoptics don’t translate to that at all. It’d be mid to high twenties, with the odd place ticking over 30c. We’d need 15c+ uppers to be hitting 35c

[SizzlingHeat]

1 minute ago, ancientsolar said:

Well, looking at the same charts last week, and comparing to next weeks.. and seeing that GFS undercooks alot of temperature, i'm calling Widely 31-35C

I think the 'red' colours are misleading you. The darker the red does not necessarily translate to hotter temperatures. You need to be looking at the 850s and thickness levels which represent the temperatures likely at ground level. The 850s on this run show widely 10-12c across the UK. With very dry ground and strong sun you would add approximately 16-18c on top of that temperature. Therefore 12 + 18 is going to provide 30c at surface level. 

The difference this week was the uppers were higher that next weekend. In fact, 13-16c widely across the UK last Wednesday and 13-15c across the west widely until Saturday which resulted in temps nudging the low thirties. 

The uppers today scraped 16c across the south resulting in a high of 32c.