Model output discussion 14/04/18

[Summer Sun]

37 minutes ago, Mike Poole said:

GEFS 12z mean looking promising to T204, next Friday, signal gets less clear thereafter.

ECM rolling out, and at T168, this really does look a good evolution with the high over Scandi, and the ridge from the Azores.  

Edit: double down on that with the T192:

 

Maybe this year we'll get a Flaming June

Edited May 30, 2018 by Summer Sun

[mb018538]

I’ve been keeping an eye on how crazy the warmth in Norway is....

since the 22nd, maximums in Oslo have been: 24/25/27/28/28/28/24/27/30

the forecast maxima for the next 9 days:

29/30/31/31/28/26/24/28/28

Surely this must be up there with all time heatwaves, including summer months! To get a run like that from mid May to early June is mind boggling really.

[Sweatyman]

15 minutes ago, mb018538 said:

I’ve been keeping an eye on how crazy the warmth in Norway is....

since the 22nd, maximums in Oslo have been: 24/25/27/28/28/28/24/27/30

the forecast maxima for the next 9 days:

29/30/31/31/28/26/24/28/28

Surely this must be up there with all time heatwaves, including summer months! To get a run like that from mid May to early June is mind boggling really.

Can only dream here

[gottolovethisweather]

24 minutes ago, Matthew. said:

Parts of Norway/Sweden warmer Spain at the moment as they’re experiencing northern blocking with a trough underneath

Yes, saw that on the Beeb earlier. Weird weather patterns and from Tamara's post up thread and that of seasoned others, not a lot of change in the coming days. Whilst, risking another moan, I urge people not to use specifics such as lovely, gorgeous or whatever in their postings as clearly, unless the cloud actually clears, regional differences will be vast. Frosty's quote "the devil will be in the detail" could have been in use for many days of late and is most pertinent, given the endless gloom descended on Newbury the last few days.

[I remember Atlantic 252]

22 minutes ago, mb018538 said:

I’ve been keeping an eye on how crazy the warmth in Norway is....

since the 22nd, maximums in Oslo have been: 24/25/27/28/28/28/24/27/30

the forecast maxima for the next 9 days:

29/30/31/31/28/26/24/28/28

Surely this must be up there with all time heatwaves, including summer months! To get a run like that from mid May to early June is mind boggling really.

they don't have problem of north sea misty low cloud

[gottolovethisweather]

On 24/05/2018 at 17:58, gottolovethisweather said:

I noted such forecasts on the Beeb were routinely skipped past in favour of the more important weekend forecasts, but a forecast FAIL is a forecast #FAIL whichever whey they choose to paint it. See my post below for more on this total shambles of a forecast, which could indeed recur itself in the coming days. Not wanting to pee on the chips for people, this forthcoming weekend, but IF and when the crud comes in, you should drop your expected forecast maximums by some MARGIN, that would be my advice, as witnessed today in Newbury and many other parts down South.

 

 

This was a requote of my own understanding of the forecast synoptics six days back and the threat of it becoming a recurring setup. Well, it turned out to be very accurate, not that I begrudge others of plentiful sunshine or storms.

Edited May 30, 2018 by gottolovethisweather

[Matthew.]

Just now, I remember Atlantic 252 said:

they don't have problem of north sea misty low cloud

It’s all about where the centre of the high is bringing enormous amounts of sunshine too. In the last week the pattern has developed a strong Scandinavia high with no Azores high linking over the U.K. so instead we end up with northern blocking to the northeast with bags of cloud moving over the North Sea in the flow. Great for Ireland and northwestern parts though

[gottolovethisweather]

9 minutes ago, Matthew. said:

It’s all about where the centre of the high is bringing enormous amounts of sunshine too. In the last week the pattern has developed a strong Scandinavia high with no Azores high linking over the U.K. so instead we end up with northern blocking to the northeast with bags of cloud moving over the North Sea in the flow. Great for Ireland and northwestern parts though

And link that to additional daytime detritus from overnight storms (which have been pretty ferocious and amazing to boot for May) and it is a gloomfest for parts inland as well.

Edited May 30, 2018 by gottolovethisweather

[Frosty.]

7 minutes ago, gottolovethisweather said:

This was a requote of my own understanding of the forecast synoptics six days back and the threat of it becoming a recurring setup. Well, it turned out to be very accurate, not that I begrudge others of plentiful sunshine or storms.

Yes I really hope eastern areas cheer up with less north sea filth to endure but the overall pattern continues to look very impressive..the Ecm 00z / 12z for example show increasing continental heat next week..

[Frosty.]

Looking at tonight's Ecm 12z ensemble mean there is plenty more potentially very summery weather to look forward to regarding warmth / heat / sunshine & for storm enthusiasts, more thunderstorms although the coming weekend looks calmer with generally drier and sunnier conditions, at least across most of england and wales but still with low cloud / mist issues for some eastern counties bordering the north sea. As I said earlier, the devil will be in the surface detail but on the face of it, these are very good looking charts for the early part of june..across many areas!

[Alex]

I live in the Southeast and the weekend just gone was brilliant, three days of sunny warm weather so before I start discussing my own thoughts, not all eastern areas fare badly with an onshore wind. Essex does relatively well with the shorter sea track.

Today wasn’t as good but that was more to do with residual cloud from the overnight rain/storms rather than low cloud.

Moving onto my own observations, as Tamara and others have said earlier today the pattern looks like sustaining for a while longer, AAM looks like staying on a steady upward trend for the coming days which should sustain the current pattern for at least the next 10 days. The earlier GFS output looked far too progressive in eroding the heights to the NE. Going forward it’s all to play for, even a downward trend in AAM (as long as it’s not a sharp sudden drop) should allow for at least 2/3 days of heights being pushed to the east allowing potentially a plume of hot air before the Atlantic breaks through and any recovery in AAM could see heights recover. I notice the MJO moving into phase 4-5-6 which would enhance the potential of some real heat around ten days into June. 

Many of the best summers have come from when the ENSO is in a neutral state and this year we have the right ingredients for some good weather at least! Let’s hope it continues.

 

 

[Man With Beard]

1 hour ago, gottolovethisweather said:

This was a requote of my own understanding of the forecast synoptics six days back and the threat of it becoming a recurring setup. Well, it turned out to be very accurate, not that I begrudge others of plentiful sunshine or storms.

It certainly has been a hit or miss period - we absolutely baked in Portsmouth for the whole of the bank holiday, reached 27C twice - and I can see the next 10 days being a rerun. There's still time to be lucky GTLTW!!!

[mb018538]

There definitely looks be a trend to reset back towards something of a more normal pressure distribution in the next week:

http://www.meteociel.fr/modeles/ecmwf/runs/2018053100/ECM1-192.GIF?31-12

http://modeles.meteociel.fr/modeles/gfs/runs/2018053100/gfs-0-192.png?0

http://modeles.meteociel.fr/modeles/gfs/runs/2018053100/gfs-5-192.png?0

Both the GFS and ECM go for an Icelandic low and higher pressure around the Azores by 192 hours. Jet starting to re-align to a more normal position too. Could we finally be starting to break the shackles of the current pattern.

[carinthian]

The UKMO upper air profile (500mb level ) at 144t it status quo. Again ,any convectional energy dissipates in a Northward direction followed by a renewed build of pressure in the north. The prolonged survival of this set up is quite something . Obviously it is a reverse set up to our normal management of heat energy in the summer. In normal circumstances any heat incursion into the British Isles is usually pushed away eastwards by a zonal North Atlantic trough/ flow. I think yesterdays post by @Tamara preludes as to the causes as to why this may not be happening so far in the early summer season as indicated by the chart below and that's the persistent of high pressure ridging to the north ,either with vectors to the west and east . The upper cold pool over Iberia can only help to sent any energy pulses in a NW ly direction ( against most seasonal norms ). Longer term , we may see an attempt by the Atlantic low pressure to move to its usual position in an Iceland direction but in the meantime the status quo persists and if this continues increased heat plumes are more than likely to be a feature of June weather

[Newberryone]

55 minutes ago, mb018538 said:

There definitely looks be a trend to reset back towards something of a more normal pressure distribution in the next week:

http://www.meteociel.fr/modeles/ecmwf/runs/2018053100/ECM1-192.GIF?31-12

http://modeles.meteociel.fr/modeles/gfs/runs/2018053100/gfs-0-192.png?0

http://modeles.meteociel.fr/modeles/gfs/runs/2018053100/gfs-5-192.png?0

Both the GFS and ECM go for an Icelandic low and higher pressure around the Azores by 192 hours. Jet starting to re-align to a more normal position too. Could we finally be starting to break the shackles of the current pattern.

This would certainly seem to be the case with less likelihood now of a continuation of this warm/very warm continental airflow beyond the end of next week. Still lots of uncertainty around this timeframe but a relaxation of sorts re high temps does seem likely. At least it should become less oppressive for when trying to get a decent nights kip. 

[johnholmes]

Showing the latest 500 mb anomaly outputs. They continue to show ridging as being more dominant than troughing at 500 mb. To me they do, all 3, seem to show that the pattern is, over the past 4-5 days, trying to change slightly. The upper ridges on each of them is slightly further south than a few days ago. Whether this is just a blip or something else will only become apparent in a couple of days. If it does continue then it may suggest a more westerly 500 mb flow than for some time.

I'll be keeping an eye on them over the next few days.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

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

[Man With Beard]

In fact, going a bit further :

ECM extended is now consistently signalling the end of the ridge by mid month 

[shaky]

6 minutes ago, Man With Beard said:

In fact, going a bit further :

ECM extended is now consistently signalling the end of the ridge by mid month 

Typical!!its been hot and sunny this whole month of ramadhan whilst ive been fasting but just as it comes to an end on june 15th the weather will decide to go down hill!!made this prediction before my fasting month started aswell and it loooks like it could happen now!!just typical!!

[Djdazzle]

3 hours ago, shaky said:

Typical!!its been hot and sunny this whole month of ramadhan whilst ive been fasting but just as it comes to an end on june 15th the weather will decide to go down hill!!made this prediction before my fasting month started aswell and it loooks like it could happen now!!just typical!!

16 days away - might as well be 16 years. Nothing certain yet. But of course the pattern will change at some point.

[Tamara]

23 hours ago, Tamara said:

Of course, the cycle wanes as well as waxes, so at some stage there will be a backward adjustment (probably tied into the latter stages of the current tropical cycle once it has arrived in the Pacific) but what will be important if/when any less warm and settled interlude arrives will be the measure of how much higher the next lull phase in the tropics and extra tropics is compared to earlier in May

Another post I have re-quoted, and this one only from yesterday, but its to illustrate yet again the caution of taking a pure NWP approach to evolution of the pattern and jumping to conclusions from face value intra day model suites (very much including ensembles and cluster data) that appear to suggest macro scale changes

Furthermore, and even more potentially problematic, is then extrapolating those instant conclusions from a model suite (assuming that is they come to pass) for weeks ahead

This happens in summer as any other time of year - its simply on a much smaller scale because of the absence of the snow and cold frenzy members who have no interest in weather or weather patterns beyond the winter.

The expectations of tropical convection in the Pacific later in June does not support any extended withdrawl/suppression of the ridge that may occur around mid month.

It rather implies a re-set of the ridge pattern thereafter as any such activity in the Pacific implies tropical low pressure systems there and associated westerly wind bursts - and these give rise to a downstream pattern that is also representative of a trough in the Atlantic and a downstream ridge response from this over Western Europe.

Having said that, I happily accept I should maybe have made it more clear in that quoted excerpt that downturn of AAM is related to the conclusion (*or early aborting*) of a tropical cycle and return to the Indian Ocean ahead of the next one. Notwithstanding that, its hard to see at present  how any downstream UK trough, should it evolve in the 10 to 15 day period, would sustain for a lengthy period, taking into account the factors relating to angular momentum trends (long term) that were discussed in detail both yesterday and previous posts to this over recent weeks which have continually attempted to weigh up the pros and cons of warm settled vs cool unsettled outcomes.

On the subject of pros and cons, *should* tropical convection not attain amplitude and fail to engage the Pacific then extended prospects for further fine warm spells would start to run into trouble - but there is no reason to anticipate this at this stage and its way too far head to anticipate, assess and fuss about anyway.

Its worth though taking this MJO periodicity plot of the last 3 months as support for fulfilling of June expectations. The recurrence factor and active orbit nature of the tropical cycle was also discussed yesterday and in previous posts

 

Taking a non-NWP approach doesn't mean cast iron weather prediction accuracy. The very best professional cannot achieve that, let alone any internet weather enthusiast. But it does help avoid taking NWP snapshots in time and immediately drawing instant conclusions and forward extrapolative assumptions based on them,

 

Edited May 31, 2018 by Tamara

[Singularity]

Good advice from @Tamara - it's best by far to view the models with respect to the background signals rather than in replacement of them!

For example, the GFS 00z seemed like one of the most reasonable runs in a while in that it featured a bit of a plume, followed by destabilisation and an Atlantic trough edging in, but with that trough soon fleeing into mainland Europe as ridging reasserted itself from the Azores toward Scandinavia.

The 06z did not manage to keep hold of that baton, but a run being more recent in no way means it's going to be more accurate except (usually) at the 12-24 hour range .

[I remember Atlantic 252]

UKMO 144 Yuck! clearly miserable for this location, maybe others too, but W Scotland again hot with unbroken sun

[Frosty.]

1 hour ago, I remember Atlantic 252 said:

UKMO 144 Yuck! clearly miserable for this location, maybe others too, but W Scotland again hot with unbroken sun

Why just focus on day 6?...the Gfs 12z indicates plenty of warm sunny weather for the next week or so with temperatures frequently into the low 20's celsius and some favoured areas around the mid 20's c..even the east coast is into the high teens c at times..not settled by any means but temperature wise, very decent.

PS..awesome post again tamara

Edited May 31, 2018 by Frosty.

[northwestsnow]

UKMO looks good out to 144 this evening- probably a little less aggressive with the Atlantic than GFS which really powers it up and becomes quite horride into FI.

As Karl says plenty of dry warm weather on hand even on GFS before next weekend.

[northwestsnow]

ECM looks better than GFS at 144-168..

More influence of the azores high.