Model Output Discussion 31/07/14 onwards.

[phil nw.]

As the weekend surface low fills and moves away along with much of the showery rain a weak ridge of high pressure builds north which will bring some sunshine and quite warm temperatures, particularly further south.

 

Fax for Monday along with a couple of GFS charts

 

The first half of next week in fact looks quite decent for sun and warmth in the south and east quarter but the nearby trough sees frontal systems flirting with western and northern areas with some rain at times.

 

Obviously details may change and no where can be promised any completely dry days.

 

The general picture though seems to the usual split between the nw and se with the drier and warmer conditions further the south east you are, at least for much of the coming week.

It does look like Atlantic fronts and rain make a more eastward push towards the end of the week with the possibility of heavy rain as the Atlantic air comes up against the heat off the continent.

ECM showing such a scenario for next week end.

 

that of course is a while away but something to monitor with the continental heat never far away during the coming 7 days or so.

 

So yes a mixed bag coming up i think with some sun and warmth also rain or showers but  very much dependent on location how one sees things over this coming period.

Edited August 1, 2014 by phil nw.

[knocker]

ECM showing such a scenario for next week end.

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gif5.png

 

that of course is a while away but something to monitor with the continental heat never far away during the coming 7 days or so.

 

So yes a mixed bag coming up i think with some sun and warmth also rain or showers but  very much dependent on location how one sees things over this coming period.

 

You could well be right Phil but I find that chart a bit deceptive/ The HRES is certainly going for a lower trop. closed circulation and, as you say, could be quite wet. mind it would be a bit stupid to put ant emphasis on this at this range.

[Man With Beard]

GFS 12z follows ECM 0z run and goes even further, with a proper plume event for the end of next week - 30C very likely next Friday/Saturday in central/eastern areas if it comes off. I did suggest this morning the ECM run seemed at the 'extreme' end, but the trends are certainly going one way at the moment, with UKMO T144 not dissimilar, though it would break down slightly sooner. (Mental note to me and some others: do not write off D7-D10 charts as unsettled unless there's a big fat low forecast by all charts over the UK!)

[knocker]

I wouldn't have said the 00 ECM ens was signifying a plume event.

 

 

[Summer Sun]

GFS showing an increasingly hot end to next week this afternoon

 

 

By Saturday the heat becomes less widespread with rain moving in

 

[Milhouse]

What a turnaround weve seen over the past few days, but given the way things have been going im not really suprised weve seen yet another upgrade of the warmth and dry weather. It wasnt too long ago we were seeing cool air spilling down from the north. Now its another spell of very warm and dry weather thats just around the corner.

[Man With Beard]

I wouldn't have said the 00 ECM ens was signifying a plume event.

Sure, but the ens would be the last place to show a plume as it would be watered down by the cooler runs/outliers? In any case, clearly a warm southerly is far from a done deal but all we can do is comment on the models, and this is what some op runs are showing - for now

[IDO]

The GEFS mean does not really support another plume though the SE quadrant should still get above average uppers:

 

 

Looking at the 2m temps the op is an outlier compared to its members:  

 

Though the Control is not as warm, it suggests 24-36 hours of +12 uppers as well; one to watch. GEM also not really going with the plume either:

 

 

GEM quite unsettled from mid-week with two lows bullseye UK:

 

T132:   T240:

 

With the GFS op looking unlikely, the control is probably worth looking at and that is similar to the GEM with the timing of the above two lows. However they are not as potent and the T132 Low is more west based than GEM:

 

 

 

So uncertainty still remains and although there are only a few hundred miles difference with the Long Wave pattern these translate to big differences in surface conditions especially for the SE. The UK has LP in charge till Sunday then a few days of slack pressure before the Icelandic low expands, edges E/SE, moving the Atlantic trough east. That's where the models and ensembles show scatter and more runs needed, though the liklehood is more trough dominated weather with the SE on the warm side.

 

[Milhouse]

The push of heat from the south showing up well on the UKMO

 

 

[Evening thunder]

With mean uppers of 12C into the SE I'd have thought the GFS ensembles are at least hinting at a possible plume there. Not all members showing it but some probably are. Also the ensemble 2m temps often underestimate maxima due to their low resolution (both GFS and ECM). 12C uppers could easily bring high 20's in places with enough sunshine.

 

The GEM seems to change and has seemed a tad more unreliable than other models to me, so I look at the ECM/UKMO/GFS before it, although the GFS aint always great (like them all at times).

 

As posted above the UKMO which is on average a bit more accurate than the GEM does support some kind of plume

 

And of course shows the omnipresent Scandinavian and Finnish warmth/heat and high pressure. Time to wait for the ECM.

[Man With Beard]

I'm dreaming of - GFS op run is not an outlier. It's part of a cluster containing 30%-40% of the runs, and the other runs in that cluster peak at different times:

[linarite]

What a turnaround weve seen over the past few days, but given the way things have been going im not really suprised weve seen yet another upgrade of the warmth and dry weather. It wasnt too long ago we were seeing cool air spilling down from the north. Now its another spell of very warm and dry weather thats just around the corner.

Warm maybe - dry..I think not! Edited August 1, 2014 by linarite

[SteveB]

I said in my earlier post from this morning, wouldn't take much to tap into the heat of the continent and the models are showing that this evening for later next week. 

 

Lots more chopping and changing before then I would imagine, but for now, the South & East (after this weekend) look to stay warm and fairly settled, compared to the North & West were it looks very unsettled.

 

[summer blizzard]

Certainly not cool but as above, i don't think it's especially dry.. GFS on its own in that regard building pressure very strongly.

 

[knocker]

Well the ECM HRES 1200 is briefly showing temps at most 25C in a few places. No sign of a plume. In fact quite candy ball by Sunday.

 

 

Edited August 1, 2014 by knocker

[Guest HectorTheAwesome]

The 15 degree isotherm makes its way over the UK yet again. 30 degrees in the south east.

 

[knocker]

That's assuming a very high end lapse rate.

[Man With Beard]

Well the ECM HRES 1200 is briefly showing temps at most 25C in a few places. No sign of a plume. In fact quite candy ball by Sunday.

Indeed, ECM a little more like yesterday's 12z, so definitely 'more runs needed' - I'd offer you a friendly wager on 28C being reached somewhere next Thurs/Fri though :)Incidentally, is there a difference between ECM op and ECM Hres?

[knocker]

Indeed, ECM a little more like yesterday's 12z, so definitely 'more runs needed' - I'd offer you a friendly wager on 28C being reached somewhere next Thurs/Fri though :)Incidentally, is there a difference between ECM op and ECM Hres?

 

It's 0.125deg res.against 0.5 but don't ask me the technical details. I'm sure someone else can chip in there.

[Milhouse]

'Long dry periods' rather than 'dry' is the best way to describe next week looking at this evenings models. The ECM is the most unsettled of the big 3 but the UKMO does offer some support to the GFS in raising temperatures towards the high 20s.

[Frosty.]

Tonight's Ecm 12z op run has all the right ingredients for another very warm / hot & humid thundery spell during the second half of next week with another pulse of continental conditions extending northwards across southern, central and eastern areas, especially the southeast. This is followed briefly by fresher air from the atlantic as a ridge of high pressure builds in from the southwest, eventually turning very warm again towards the southeast with high pressure close by over the near continent. For the time being, the weather looks warm and showery but with a mass of heavy rain spreading northwards tomorrow, reaching scotland later, warm, dry and sunny weather following for the south & east once the rain has cleared away but still the risk of a heavy shower. Early next week looks warm with sunshine and scattered thundery showers, longer term, the north west of the uk is likely to become most unsettled with atlantic weather for most of the time, however, it's a very different story for the southeast of the uk with a window of hot, hazy sunshine for the south and east before homegrown Tstorms  break out again and storms drift north from france across eastern england..all in all, it's a very good early august for some of us.  

[Summer Sun]

The push of heat from the south showing up well on the UKMO

 

 

 

Yep here's the 850's becoming increasingly warmer or the 2nd half of next week on today's UKMO

 

[Frank Trough]

Well the ECM HRES 1200 is briefly showing temps at most 25C in a few places. No sign of a plume. In fact quite candy ball by Sunday.

 

all well and good but the "brief 25c" wasn't showing until recently - the trend in recent days has been to settle the weather somewhat in the early part of next week. So, next sunday being 8 days away -i wouldn't like to call.

 

I'll say this though - for the south it doesn't look that bad really.

[bluearmy]

It's 0.125deg res.against 0.5 but don't ask me the technical details. I'm sure someone else can chip in there.

 

its the same model run - just how magnified the data is.  there is only one ecm op running at a high resolution.

 

incidentally, we are running at a fairly high background re uppers and thicknesses with warm SST's so any 'plume' has to be in that context. even so, i am sniffing a mid month proper plume on the ecm 12z suite.

[knocker]

Today's anomalies Has the familiar picture of the trough centred over Iceland and lying N/S just west of the UK with the GFS and ECM. Slightly above average temps with the GFS, not quite so much with the ECM Doesn't appear to be any major movement re. the Azores high.

 

What do you mean by," running at a fairly high background re uppers and thicknesses" bluearmy? Genuine question.

Edited August 1, 2014 by knocker