Model output discussion - summer rolls on

[Reefseeker]

51 minutes ago, Uncle_Barty said:

Thanks again, Tamara.

One thing - can anyone point me towards a quick-look glossary of the various acronyms used in the posts talikng about teconnections? For example, CCKW.. not a clue what it stands for or what it means?

Just a decode of the acronym and a brief outline of what it is will do me. I can then read further if I want.

Hello

There are lots of really good sources on Netweather. Have you checked out the Learners Area? Knocker posted on CCKW around three years ago, but there are a lot of threads in that section dedicated to learning. Otherwise, my personal favourite is the one set up last winter by @Bring Back1962-63 which is full of really informative stuff in the Forecast models section:

 

 

[Mike Poole]

Thankfully the UKMO seems to have lost it's bank holiday ruining low. Now has a small area of high pressure at T144:

GEM and GFS also seem to have this feature nosing in from the west, bank holiday weekend rescuer!

Its transitory but the main ridge then follows, both looking good at T240:

Some consistency seems evident in the models today, even out to day 10.

Edit: GFS at T360, and the heats back proper 

Edited August 20, 2018 by Mike Poole

[Leo97t]

Looks very easterly from day 10 so warm but probably no heatwave. Daily maxes of 26C across the south thought the first week of September. 

[Mike Poole]

Ridge looking very strong on the GEFS ensemble mean at T240 and T300:

[mb018538]

Certainly looking like a cool bank holiday coming up to see out the summer. Not a complete disaster and washout, but definitely rain to contend with.

After this it’s looking increasingly likely we will see a proper area of high pressure move in for a time, rather than short lived ridges that we’ve had recently. Not too bad overall.

[Mike Poole]

ECM take on things, first T144:

Again that small ridge just doing enough not to totally ruin the bank holiday weekend.  

And at T240:

So we now have multi-model agreement on the ridge of high pressure at the 10 day timescale, the settled warm, in some places hot start to September now more or less guaranteed in my view.

[Frosty.]

It's looking autumnal later this week, becoming much cooler and more unsettled for a time according to the Ecm 12z but then we see a gradual improvement next week as high pressure builds in and becoming generally warmer.. I think post day 10 would get even better.☺

Edited August 20, 2018 by Frosty.

[Coopsy]

40 minutes ago, Mike Poole said:

So we now have multi-model agreement on the ridge of high pressure at the 10 day timescale, the settled warm, in some places hot start to September now more or less guaranteed in my view.

Not often I see a guarantee statement at day 10. I hope you’re right 

[Frosty.]

Tonight's Ecm 12z ensemble mean looks really good longer term..As did the operational with the azores high gradually building in..a summery early september if this is right!☺

Edited August 20, 2018 by Frosty.

[Mike Poole]

13 minutes ago, c00ps said:

Not often I see a guarantee statement at day 10. I hope you’re right 

Well, it's certainly reinforced by the ECM mean at T240:

This system will be slow moving giving prediction at day 10 possible.  But every model is showing it.  Here's the FV3 my current favourite model 12z, Here at T240 and T 360:

What interests me is that this resembles the situation in the middle of June, that is a recurring pattern, I think this could start a significant warm dry period from start September.

[Man With Beard]

These clusters continue to be absolutely epic for the start of September 

General rule: 582 line to the north of your location = nice! 

But of course it will require extra special synoptics to get a proper heatwave in September. Can be done (35C is the record). These ensembles are a good starting point! 

[Leo97t]

Just look at how widespread that heat is for September. Will do wonders for the CET

[johnholmes]

Is this the first indication on the anomaly charts of height rises and ridging developing in the area needed for a warmer/hotter spell? Early days as it is the first one and NOAA is not yet showing this. I'll be keeping an eye on these for sure.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

[Frosty.]

The Gem 00z turns into a peach next week with increasingly warm anticyclonic conditions nationwide, the Gfs looks good too with high pressure getting the upper hand..  In the shorter term, there's a much cooler unsettled spell on the way from the NW later this week but the form   is for a gradual improvement next week with pressure / temperatures rising.☺

Edited August 21, 2018 by Frosty.

[mb018538]

25 minutes ago, johnholmes said:

Is this the first indication on the anomaly charts of height rises and ridging developing in the area needed for a warmer/hotter spell? Early days as it is the first one and NOAA is not yet showing this. I'll be keeping an eye on these for sure.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Surely that's because those plots are a mean from 168-240 hours though. The high isn't really forecast to build strongly in that timeframe, so of course it won't show up yet!

[danm]

A generally very good outlook on this mornings runs for those who want dry, sunny, warm weather. 

Much cooler later this week and into the weekend, but even then there should be some decent sunny spells. 

Into early next week we see the N/S split developing early on with low pressure still close by to the north, high pressure to the south. After that, growing agreement for the high pressure to extend to most parts of the UK at the turn of the month. 

Down here in the SE it’s been a warm few days, mid 20s and humid with some decent sunshine at times. A cooler blip this weekend and then it looks like getting back to warm, dry, sunny weather. 

[Frosty.]

The Gfs 6z operational shows some nice settled pleasantly warm barbecue weather developing next week, especially later next week under strong ridging / high pressure and temps into the low 20's celsius..gets even warmer into early september!☺

Edited August 21, 2018 by Polar Maritime
To move discussion on.

[mb018538]

00z ECM clusters all showing high pressure dominating from day 10 and beyond. Summer isn’t over just yet.

Edited August 21, 2018 by mb018538

[Leo97t]

What synoptics would be required for more extreme heat into the 30s in September. Does someone have the charts from 2006 or 2016 when it hit 30C. If the continent is hot enough I certainly think we could have a go at some more heat with the strength of the anticyclone which is consistently being modelled to move in at the beginning of September

[mushymanrob]

3 hours ago, mb018538 said:

Surely that's because those plots are a mean from 168-240 hours though. The high isn't really forecast to build strongly in that timeframe, so of course it won't show up yet!

..... but the evolution to it will be becoming manifest in that time period.  imho the anomaly charts are lending some support to the deep fi evolution the gfs is hinting at.  and with that in mind, personally im optimistic for some settled warmth, even heat.

[mb018538]

Generally the same - south or southeasterly flow, 850s over 15c.

The spell in 2016 was exceptional - 34.4c in Gravesend.

850s were around 18c, which is very rare so late in the year. It was the first time 90f had been reached in September since 1949! 

[Yarmy]

59 minutes ago, Leo97t said:

What synoptics would be required for more extreme heat into the 30s in September. Does someone have the charts from 2006 or 2016 when it hit 30C. If the continent is hot enough I certainly think we could have a go at some more heat with the strength of the anticyclone which is consistently being modelled to move in at the beginning of September

Meteociel has the NCEP Reanalyses archive for looking at historic synoptics.

https://www.meteociel.fr/modeles/archives/archives.php

 

 

[johnholmes]

4 hours ago, mb018538 said:

Surely that's because those plots are a mean from 168-240 hours though. The high isn't really forecast to build strongly in that timeframe, so of course it won't show up yet!

I never said anything to contradict that, the time scale is always 6-10 days=144-240 hours. That is the period in which I am 'suggesting' they 'may' be starting to show such a happening. Of course they are mean charts something I have always tried to make clear. Because of this they are almost always less volatile than the daily 2x or 4x daily synoptic outputs (as I call them). Equally they are not often far off the mark as to what the 'average' upper air pattern turns out to be. Again I always emphasise that great care must be exercised in their use. 

Edited August 21, 2018 by johnholmes
spelling

[Cheshire Freeze]

2 hours ago, mb018538 said:

00z ECM clusters all showing high pressure dominating from day 10 and beyond. Summer isn’t over just yet.

Well, to be pedantic, meteorological summer ends on 31st August regardless of weather conditions

Autumn is almost here. 

To be fair though, it does look like we'll see another warm period early September. However, unlike the similar June spell, the sun won't be anywhere near as strong, so it shouldn't feel as oppressive sitting out in the midday sun. 

[Singularity]

 

I'm keeping an eye on the little ridge over France and kink south in the trough base showing up for this Sunday, as there might just be enough amplification in the flow ahead of the flattening oprocess (i.e. move away from Nina-like) to drop a small low down toward Iberia and prevent the main trough from pushing cleanly east of the UK. Potential for some warm but rainy weather for the SE'rn half of the UK Sun-Mon if that transpires.

Still expecting the tropical maritime flow to dominate again by early next week... but those delays to the tropical cycle have been very frustrating this month and a reminder that we can only take longer-range forecasting so far (we can see the overall direction of travel, but the pace of developments is subject to great uncertainty). It's so very painful to know what might well have been... you have to be very sturdy of mind to be a climatologist!