Model Output Discussion 22/07/12 Onwards.

[Robbie Garrett]

Do you mean, not until after??

Affirm. Thanks, will correct.

[PubliusEnigma]

What surface obs did you use to place the cold front? It's 1830Z now and no change has gone through Cardiff, but that analysis suggests it should have. If it's based only on the satellite imagery, that's a risky business.

Things moving nicely along now, a dry cold front has cleared through your neck of the woods. It would have really only have been noticeable as a drop in temps. The next one is knocking on your door now and again temps will fall further behind that one. A week front is across London right now and down towards Isle of Wight. That is moving east slowly with some high level shower activity which is dying out now. The thundery risk has passed for the south east albeit some heavy showers possibly with a rumble out in the channel off the coast of Sussex and Kent will be around for a few more hours. Chart below shows how the modelled cold fronts have arrive about 6 hours earlier than the official forecasts.

[Bobby]

Things moving nicely along now, a dry cold front has cleared through your neck of the woods. It would have really only have been noticeable as a drop in temps. The next one is knocking on your door now and again temps will fall further behind that one. A week front is across London right now and down towards Isle of Wight. That is moving east slowly with some high level shower activity which is dying out now. The thundery risk has passed for the south east albeit some heavy showers possibly with a rumble out in the channel off the coast of Sussex and Kent will be around for a few more hours. Chart below shows how the modelled cold fronts have arrive about 6 hours earlier than the official forecasts.

I can see the cold front approaching here from the NW, a layer of high-mid cloud. Can't come soon enough IMO.

The GFS 06z has brought the troughing closer over us than out to the W like the 00z, more in line with the ECM and more likely I think. Next week could be a bit of a washout for some.

GFS rainfall accumulation

NAEFS has been showing the troughing anomaly fading into the second week of August, so perhaps things turning a bit more settled again. No sign of a proper pressure build though, so things probably staying mixed if not a washout.

NAEFS +300

The blocking over Greenland remains so still dodgy.

Edited July 27, 2012 by Barb-

[johnholmes]

true enoug Barb but

The link below for the 500mb ECMWF-GFS output from this morning, valid for 6 August, shows much the same. What it also shows is that the upper winds, thanks to the probable upper ridge over the Greenland area and, what the NAEFS does not show, is that an upper low/trough, will give mostly a flow from south of west. This should mean temperatures, away from the exposed NW and possibly western fringes, will generally be a reasonable level. Unsettled weather for much of the time over the country but something of a NW-SE split seems probable with less unsettled and thus warmer conditions the further away from the exposed NW you are.

http://www.meteo.psu...0z/hgtcomp.html

the NOAA output shows much the same, so with similarity over the past 2-3 days from all anomaly charts one can have a reasonably confident idea of the overall weather patterns going into the second week of August.

Edited July 27, 2012 by johnholmes

[Scorcher]

I agree John, still lots of overly negative posts in here about the next week. Maybe that's due to the preferences of the posters for cool, unsettled weather but I think some of the posts are misleading. Some suggesting the only positive is the fact that it's going to be 'better than June'. That's a big understatement in my view as the south should reach at least the low 20s for much of next week. Compare that with June's temperatures which were widely in the mid teens for much of the month!

[Gavin P]

Here's todays 8-10 Day model based ideo musing:

Very Unsettled Weather Coming Back: http://gavsweathervids.com/

Overall, low pressure back in control next week.

[Summer Sun]

Cheers Gavin its looking very uninspiring again and hope that gps suggestion of the trough blowing westwards is the case as the charts next week look pretty rancid to say the least.

Although it may look uninspiring I don't think we'll see conditions as bad as we have done so far this summer, most areas should get a mix of sunshine and showers some areas in the north may see longer spells of rain at times but I think the south and east will see some decent bright spells, whilst all areas will get drier periods at times

Edited July 27, 2012 by Summer Sun

[Frosty.]

This evening's ecm 12z is showing a mainly unsettled 7-10 days ahead but with a glimmer of hope towards the end of the run with high pressure building from the southwest but the first full week of the olympics looks like having a mixed bag of weather but will probably be the best part of the uk to be with warm dry spells between the rainy days and the further northwest you are in the uk looks likely to be the coolest and most unsettled but in general it's a return of the poor weather which has dominated this awful summer.

[BLAST FROM THE PAST]

This evening's ecm 12z is showing a mainly unsettled 7-10 days ahead but with a glimmer of hope towards the end of the run with high pressure building from the southwest but the first full week of the olympics looks like having a mixed bag of weather but will probably be the best part of the uk to be with warm dry spells between the rainy days and the further northwest you are in the uk looks likely to be the coolest and most unsettled but in general it's a return of the poor weather which has dominated this awful summer.

We've had that hope and forecast before now...........

BFTP

[Frosty.]

We've had that hope and forecast before now...........

BFTP

It's been that kind of summer hasn't it Fred, very often reduced to glimmers of hope in FI but at least southern britain has had a hot sunny spell this week with temps touching 30.7c in london yesterday but the models are not looking good for next week with low pressure spreading in from the west and then sticking around for a few days but not a total washout and the southeastern corner especially looks warm and dry at times with temps back into the low to mid 70's being closest to the anticyclonic hot weather over france but with rain and cooler temps in the low-mid 60's F on some days but the worst weather will probably be in the northern half of the uk next week.

Edited July 27, 2012 by Frosty039

[Bobby]

I guess the crickets and tumbleweed in here reflect the current output, all the models looking unsettled for the forseeable future with plenty of rain for many.

Tuesday-Wednesday looks especially wet after a few days of showery weather

It seems the main trough is sucking in smaller troughs which are helping to keep it going,

ECM +240, trough still in charge

The NAEFS now shows the blue anomalies reappearing later, no sign of a proper pressure build for sure. So mixed or unsettled for the first half of August would be my bet.

The Greenland high doesn't want to go anywhere this year.

[Methuselah]

But, with the LPs around NW Scotty instead of S England, temperatures shouldn't go too low? Pretty average stuff, I'd imagine?

[Summer Sun]

The Greenland high doesn't want to go anywhere this year.

You can be almost certain it will vanish come Autumn and Winter leaving the coldies to say, if only it had stayed where it was in summer

Anyway short term and GFS paints an unsettled picture this morning right out to August 13th, of course it won't be rain all the time but more a case of sunshine and showers, with temperatures closer to average

UKMO is also unsettled

ECM also paints an unsettled picture

The south and east should see some decent weather but that's about it really

Edited July 28, 2012 by Summer Sun

[mountain shadow]

But, with the LPs around NW Scotty instead of S England, temperatures shouldn't go too low? Pretty average stuff, I'd imagine?

Certainly better towards the south east but the summer wash out continuing pretty much everywhere.

[William of Walworth]

You can be almost certain it will vanish come Autumn and Winter leaving the coldies to say, if only it had stayed where it was in summer

Anyway short term and GFS paints an unsettled picture this morning right out to August 13th, of course it won't be rain all the time but more a case of sunshine and showers, with temperatures closer to average

UKMO is also unsettled

ECM also paints an unsettled picture

The south and east should see some decent weather but that's about it really

All true, and I agree with that summary right now, but I would still advocate caution for FI (by which I mean beyond days 7 to 10 from now). As always for any FI really!

We've seen a fair few switches in prospects over the last few days. That being so, we should still be watching out for possible changes in detail and positioning over coming runs/days.

If anyone is ruling out any chances of more of a HP influence (note emphasisis -- I don't necessarily mean any kind of FULL pressure build) nearer the S into week 2 (ca 8-10 August?) -- well that might prove over confident at this still-early stage.

[Bobby]

You can be almost certain it will vanish come Autumn and Winter leaving the coldies to say, if only it had stayed where it was in summer

To be fair the last 2 winters out of the past 3 had plenty of high pressure blocking over Greenland producing 2 of the coldest winters ever. If the blocking over Greenland continues as it is then another cold winter might not be unexpected...

[shedhead]

Not a lot of model discussion going on in here again, which kinda lends weight to the arguement that (as in Winter) most members are only interested in model discussion when the models are showing what they want to see.

Looking at the short to medium term LP still looks set to be the dominant feature, so remaining unsettled, with showers or longer outbreaks of rain giving a rather Autumnal feel at times. On a +ive note though London and the SE should escape the worst of these conditions, with pressure remaining high enough to at least occasionally give some half decent weather and temps close to normal.

The period around T+168-192hrs is now starting to look interesting to me, with the chance of LP remaining far enough SW to allow a drier, warmer continental flow to develop for England and Wales in particular.... nothing written in stone there yet, but maybe one to keep and eye on.

Edited July 28, 2012 by shedhead

[camiscool]

Looks like my holidays going to be a washout even in rhodes is this an error?

http://www.bbc.co.uk/weather/6301777/extended

[Methuselah]

Not a lot of model discussion going on in here again, which kinda lends weight to the arguement that (as in Winter) most members are only interested in model discussion when the models are showing what they want to see.

Looking at the short to medium term LP still looks set to be the dominant feature, so remaining unsettled, with showers or longer outbreaks of rain giving a rather Autumnal feel at times. On a +ive note though London and the SE should escape the worst of these conditions, with pressure remaining high enough to at least occasionally give some half decent weather and temps close to normal.

The period around T+168-192hrs is now starting to look interesting to me, with the chance of LP remaining far enough SW to allow a drier, warmer continental flow to develop for England and Wales in particular.... nothing written in stone there yet, but maybe one to keep and eye on.

Which is, IMO, all the more odd - considering that the latest runs contain something for just about everyone. Barring any of Piers's 'hail tornadoes' that is...

[Summer Sun]

Looks like my holidays going to be a washout even in rhodes is this an error?

http://www.bbc.co.uk...301777/extended

3 days of sunshine and light showers with temps no lower than 34c is hardly a wash out those showers may not even arrive which is what is shown here - http://www.holiday-w...t/fourteen-day/

GFS 06z follows on from the 00z with unsettled weather taking over again so a mix of sunshine and showers with temperatures close to average and feeling warm in the sun

Edited July 28, 2012 by Summer Sun

[camiscool]

why do both these websites have such different forecasts ? all i wanted was a week of sun and thats what i was expecting ...probs wont happen now ?

[Frosty.]

A quick mention about the olympic opening ceremony last night..it was stunning BUT the models today are far from stunning and the week ahead looks like delivering a lot of rain to the uk. Monday is probably the best day of the week, especially in the south as a flat ridge pushes east but tuesday looks rainy in london and across the rest of the uk but then the main focus of the rain looks more concentrated in the north and west of the BI with london and the olympics possibly having a few drier and brighter days before the rain returns with a vengeance next friday. The ecm 00z is not looking as promising at the end of FI as the 12z last night with no hp building from the sw and instead the 00z has a trough in control, there is a moment on the gfs 06z when things are looking better but that soon changes and the 6z is a generally unsettled run, warm at times in the se but most of the uk is coolish and unsettled..a quick look at tomorrow indicates some heavy and frequent showers which will also affect the olympics but then monday looks better.

Edited July 28, 2012 by Frosty039

[bluearmy]

The 06z op digs the trough to our sw sharper than other runs and is not good for the games. Let's hope it's not a trend setter. It does look familiar though.

[Snowy Easterly]

im surprised no one has commented about the UKMO meteociel charts being faulty for days now, it keeps showing sundays 2 AM chart at T120 and showing intensely low heights in tenerife and north africa,

[Summer Sun]

A deep low for the time of year is showing up on the 12z tonight welcome to August

By Thursday it moves away

One thing that looks fairly certain is it won't be all that cold with temps in the high teens low 20's for most of england and wales

The remainder of GFS is unsettled with sunshine and showers likely for many