Model Output Discussion 31/05/14 onwards.

[phil nw.]

A new thread then to continue discussions on the Model outputs as we go into the first month of the meteorological Summer.

 

Current outputs continue to show a more unsettled outlook gradually spreading in off the Atlantic as low pressure again takes control by mid-week.

No early sign of a quick way out of this rather static pattern and although there are a few hints that the position of the Atlantic trough may ease west in week 2 we are still waiting for our first real signs of a fine and warm spell.

 

GFS mean charts for day 5 and 10 show the current forecasted 850hPa pattern with the expected surface features.

 

 

 

Please continue to post on topic in this thread and that is any views/comments specifically around current model charts or related data.

 

Just a reminder we do have 2 other model threads where members can post-more in-depth here

http://forum.netweather.tv/topic/76236-in-depth-model-discussion-and-summaries/

 

or a more relaxed thread for general banter or chat related to the model outputs here

http://forum.netweather.tv/topic/79882-model-banter-moans-and-ramps-springsummer-2014/

 

Ok continue discussions below when ready.

Edited May 31, 2014 by phil nw.

[Man With Beard]

Well I've had a good look at the GFS 06Z and GEM 00Z ensembles and I can't ever remember so many ensemble members going very warm in the latter stages - perhaps 17 of 20 GFS ensembles over 10C at 850 by T300. Of course it's too far off to base a forecast on but it's worth watching to see if the trend continues, as it may mean a very strong signal for HP development by D10.

[Summer Sun]

GEM looking better this afternoon albeit still in FI with pressure slowly starting to build it wouldn't be completely dry nationwide but rain / showers would certainly start and become more isolated with time

 

[Captain Shortwave]

So again probably a 30% chance of something warmer developing next weekend (especially in the East), the GFS and GEM ops seem to make it miss the UK though. UKMO whilst out to T144, it does look more favourable.

 

Beyond that the ensemble trend seems to be a movement towards a more typical Euro/Scandi high with the jet passing over the top. There are definitely sniffs frm the operationals too on this

GEM looking really strong on this this evening.

Definite hope for something better developing in 7-10 days time.

GFS ens

Certainly scope for this evolution from these too. The extended ensembles showing more of a UK block than anything else. 

Edited May 31, 2014 by Captain shortwave

[knocker]

Been out all day and haven't looked, probably a good thing but I see the GFS ens is still singing the same hymn.

 

[Captain Shortwave]

 

If the ECM is on the right line then next weekend could get interesting...

[bluearmy]

Just looked at the GFS model up to 150 hours ahead and am pretty disappointed what I see for early June. Not very inspiring at all.

Good job its the gfs then! ecm op goes plumey next weekend for the s of the uk

[Summer Sun]

Improvements from ECM once more this evening with the potential for some very warm and thundery air to move up from the continent next weekend

 

 

Could get pretty interesting next weekend if that plume made it to us

Edited May 31, 2014 by Summer Sun

[damianslaw]

Reliable timeframe - a static pattern with a slow moving trough becoming anchored over the country, locked in thanks to strong heights to the NW and NE.

 

The models are then showing heights to the NE advecting further west forcing the trough to move SW and thus enabling a possible southerly - airflow, and an unstable one to boot thanks to the proximity of the trough - ECM is showing this, UKMO looks to be heading this way, and GFS isn't far off showing such an evolution as we move into next weekend.

 

The building blocks to a settled fine spell from such synoptics relies on the influence of heights to the east and south east which if they can merge would force the jet to align on a NE-SW axis and we would then be under the influence of a warm scandi-euro high. However, we could just as easily see major disturbance in the southerly flow which would act to pull the trough back across the country and we will be back to square one.

 

Back to now and we have significant northern blocking, notable by its absence these past 12 months, but ominously appearing just in time for summer...

[draztik]

Yes, next weekend, Saturday especially looks like it could be rather warm in the SE of England if ECM is right. Met Office clearly trending towards this, as their top temperature for London is between 17C and 28C/BBC website.. So it could go either way! Will keep an eye on the ens.

[ANYWEATHER]

Interesting plume for this time next week on ecm, but we have to remember that plume events are pretty rare in the uk' and given the unreliable timeframe, its worth a mention of extreme caution on this one! The 500mb chart shows still an unsettled picture from both gfs and ecm up to and past T168.....

[legritter]

Well gang it looks like some interesting times could be on the cards ,potential looking at tonights charts for some lively weather later next week but charts also toying with the idea of some warm humid air but as usual at this range the distant horizon becomes blurred .so its the start of SUmmer but cast our minds back to the start of Winter ,Dec the Ist 2013 what lay ahead ,Little did we know at this stage ,thats what makes our hobby so interesting ,is there a beast lurking over the Horizon if there is please go a little gentle with us ,take care all and STellas all round Cheers .

[knocker]

Yes looking at the ECM ens I would have thought there is some way to go before a plume materializes.

 

Edited May 31, 2014 by knocker

[summer blizzard]

Interesting outputs this evening.

 

The Euro, GEM and GFS appear to largely back this mornings variations. The Euro is unsettled, then gets messy, then finally admits defeat. The GEM is unsettled, gets messy but has the high win out. The GFS tries to get messy but largely remains unsettled.

 

As some have noted though there is the chance for a few T storms.

 

All i can say for certain is out to day 8, the models all largely back the unsettled pattern.

 

[Alex]

Wonder what the ensembles are indicating summer blizzard?

It's a good point pjl20101 - however despite some interesting trends - we should still look to our SW for a pressure rise. Next weekend looks interesting for a convective fan - detail is far from set but it looks like a plume of warm air will steadily rise northwards as the mean trough backs west however it never really gets far enough away for the plume to be able to really impact our weather apart from say the far southeast (Essex and Kent?).It's the time after this that interests me the most, does the trough back further west? There are signs it will and if it does - we maybe onto the first nationwide summery spell and it is the rise from the SW that will look to link up with any ridge to our north. Ensembles suggest a drying/warming trend for midmonth.http://www.wetterzentrale.de/pics/MT8_London_ens.pngSome interesting model watching time to come in the next few days to see if all of this comes into play.

[Polar Maritime]

Yes the GFS is showing a nice plume out at 300hr. A long way out, but interesting all the same. Mid-Month still seems to be the tipping point to something more settled. 

 

 

Edited June 1, 2014 by Polar Maritime

[Captain Shortwave]

Regarding next weekends plume, the GFS and UKMO say yes and the GEM says no and gives a rather wet (if still warm) Saturday.

But as ops can chop and change a lot then things will swing around a lot.

GFS ens are a definite yes this morning.

Mean hitting +12C in the far southeast, nice.

Looks like beyond that, there is still a good chance of conditions becoming more settled and remaining warm as high pressure asserts more general control. Would be nice to see some movement from the metoffice on this one, but at least next weekends event is kind of being mentioned.

GFS ens again a yes to this

Interest wise this summer has well and truly had the gas lit. 

Edited June 1, 2014 by Captain shortwave

[knocker]

To plume or not to plume. That is the question. Old Willie knew a thing or two.

 

first the GFS ens from the 18z run. Not much changes there but the deep upper low is significantly positioned NW of the UK.

 

Regarding the plume and next weekend,. At 00z on Sunday there is a deep upper low SW Ireland and the influence of same is still affecting the UK on Monday giving a SW flow over the UK.

 

The surface analysis at 00z on Sunday has a low 998mb SW Ireland with a unstable SW airstream over the UK. By Monday the low is in mid Atlantic and a ridge from the Azores high is stretching into N. France bringing a light westerly to the UK which remains mainly dry.

 

The temps for the weekend are very to quite high. Saturday is looking at temps into the low 80s with Sunday being somewhat cooler as the very warm air drifts east into the North sea. Briefly the incursion of this warm air begins on Friday and is gone by Monday.

 

The jet stream on Monday is wrapped around the UK looping down from the NW and then north up the North sea.

Edited June 1, 2014 by knocker

[Captain Shortwave]

Well that's the GFS/UKMO and ECM going for potentially the warmest day of the year so far next Saturday (more so in the south), 6 days away but it has a good chance.

Looks like going bang Saturday night into Sunday.

ECM manages to phase the upstream low off the Eastern seaboard with the low west of the UK unlike its previous run

Pressure should rise near the UK now as the broad Atlantic trough takes hold. Well unless the ECM throws some dubious later frames. 

Edited June 1, 2014 by Captain shortwave

[mushymanrob]

eh?.... not sure what some are meaning this morning.... there is a brief plume next weekend on all models (big 3)

 

ecm

gfs

ukmo

 

so from a week of cool rain, to a short spell of humid, muggy, warmer rain...could well be thundery too. IF we are lucky we might get some warm sun...into week 2 of june and its far from clear as to what might evolve, the 8-14 day anomaly shows this

 which could lead to some very warm sunny weather especially in the north and northwest.

 

however the ecm this morning

doesnt really agree , and the good old gfs (Go For Summer...lol) as always brings on high pressure and summer proper... but the gfs always has had its fi tease.

 

so there is some small hope of something into week 2 evolving, but first we have a pretty rotton week to get through with no firm promis of anything better to come.

[IDO]

The trend continues from NOAA for the trough to push west in the 8-14 day time frame: 

 

As it is a seven day anomaly it is quite likely at D14 that trough is further west than its current chart position.

 

It has always been the question as to where the renewed Atlantic energy goes. The models are coming closer together on this but there are still variations. The main agreement is broadly in line with the GFS 0z run where the  initial flow stalls over the UK and the following low digs into the Atlantic, well to the west of the UK:

 

 

 

This displaces the trough further west than the last time. This will promote an Euro ridge and there is a possibility the UK, mainly S/SE, will benefit from that transient ridge for next weekend:

 

 

However this looks only temporary on the GFS, as the continued Atlantic flow digs deeper into the Atlantic trough squeezing the low near Ireland back NW; keeping the UK in a slack setup from early week 2 as the pattern develops:

 

T192: 

 

From then the continued trend of a pressure rise for the UK: 

 

ECM and GEM are both in line with the trough developing further west but there are timing, flow intensity and amplification issues.  For example at T192 GFS more meridional than ECM, with the latter doing its default cut off upper low and flattening the upstream:

 

D8  D9: D10: 

 

ECM's tendency to split the jet alters the whole dynamics of the pattern. Not a promising chart as we head to mid-June. However ECM from D7-10 have been throwing outliers as if they are going out of fashion Last night was a case in point:.

 

 So I will stick with GFS trend to build pressure close to our East.

 

GEM more meridional than ECM but has the Atlantic trough on a NE to SW axis: 

 

The UK then split; the more settled E/SE.

 

So a cool week oncoming from the GFS:  

 

With the brunt of the rain more NW centric; next 8 days totals:  

 

Then the UK on the border of warm weather though not the settled HP variety. 

Edited June 1, 2014 by i'm dreaming of...

[knocker]

Yes the ECM ops is looking at some high temps in the south on Saturday but unsettled again by mid week.

 

[Polar Maritime]

So there is some small hope of something into week 2 evolving, but first we have a pretty rotton week to get through with no firm promis of anything better to come.

 

Yes Mushy, That just about sum's the models up this morning.. There is only "small hope" as always when looking out to week 2, But at least the interest is there in showing the evolution.

 

The end of next week looks a complete wash-out for now.

 

Edited June 1, 2014 by Polar Maritime

[Man With Beard]

Sorry can't post links - but yet again, GFS ensembles mean goes above 10C at 850hpa for several days mid month i.e. very warm. Very consistent, which often signals something. Potential building imo.

[knocker]

The ens mean St and end of run