Model Output Discussion 18z 28/07/13

[The Northern Ramper]

Going to South Devon for two weeks on Saturday, oh how I am loving these charts

[Milhouse]

Going to South Devon for two weeks on Saturday, oh how I am loving these charts

 

Nothing is nailed on and the specifics are still to be confirmed but the idea of a warm/very warm and settled end to August is growing support. This would bring some lovely conditions for Devon and a little reminder of how stunning July was.

 

Edited August 13, 2013 by Milhouse

[The Northern Ramper]

Nothing is nailed on and the specifics are still to be confirmed but the idea of a warm/very warm and settled end to August is growing support. This would bring some lovely conditions for Devon and a little reminder of how stunning July was.

 

I am not fussed about searing heat (although I wouldn't mind whilst sunbathing on the Beach) I would be happy with dry, sunny and 20 degree's.

[ANYWEATHER]

We have high pressure building strongly and quickly from the weekend onwards! The big question is how long will the fine weather last:? Models are not convinced on the long length of the settled spell, even how warm it will be? To be honest I Really think this is a late summer burst of good weather, perhaps September will buck the trend  

[ANYWEATHER]

Going to South Devon for two weeks on Saturday, oh how I am loving these charts

Next week looks good.perhaps second week nots so good

Edited August 13, 2013 by ANYWEATHER

[Man With Beard]

Been away a few days, come back and I must say how well the mid-range forecasts did last week - many predicted HP rising from 20th Aug and today the higher definition runs are still predicting HP rises on 20th Aug. Good stuff!

[draztik]

Glorious! HP incoming without the debilitating heat of July! The gfs ensembles look a pretty picture tonight!

[Summer Sun]

Not bad at all from ECM July all over again minus the intense heat for now

 

 

[Frosty.]

The Ecm 12z rounds off a great day of model viewing as far as i'm concerned, there is now very solid support for the increasingly warm and anticyclonic outlook, I think the heat potential will increase as time goes on because there is a very good chance the high will become centred to the southeast or east of the uk at some point during the last third of august, this looks like being the perfect ending to an excellent summer, and the met office update today was very encouraging.

[Captain Shortwave]

Looked through the GFS ensemble members and only found I think 4 members showing this shortwave, a couple more show a kink in that vicinity and the rest show nothing. 

The importance of the shortwave if it were to verify would be pretty high for many reasons good or bad.

If it tracks into the UK of course it brings more rain though it would be reasonably warm.

If it tracks north of the UK it could trigger a surge of warm uppers from Spain.

Or it may not exist at all, but with both the GFS and ECM ops showing this, it's definitely worth keeping tabs on in future runs. 

I would be lying if I said I was sure most areas would be dry from the 20th, also if I said there was no chance of any significant heat in the 7-10 range.

Settled and warm looks the form horse after the coming weekend which will please many. More specifics beyond this pending further runs.

Will update this with the ECM ens when they come out in a few minutes.

Well ECM keeping it's cards well and truly hidden, pressure highest to the South/South west with the jet over the far north of Scotland.

Edited August 13, 2013 by Captain shortwave

[J10]

At this stage looking good for the Bank Holiday weekend, the models must be faulty.

 

Seriously though if this comes off, this will mean each summer month has had a good spell of weather, cannot remember the last time that happended.

Edited August 13, 2013 by J10

[Captain Shortwave]

At this stage looking good for the Bank Holiday weekend, the models mut be faulty.

 

Seriously though if this comes off, this will mean each summer month has had a good spell of weather, cannot rememebr the last time that happended.

Must have been 2003. June, July and not forgetting the first 10 days of August. All 3 months had good hot summer spells.

[William of Walworth]

Delighted by all of today's detail, thankyou all for posting it, and thank you for the class level of analysis!

 

Next week looks lovely, up to and including Bank Holiday/my birthday weekend, with very little dissent showing for this greatly improving trend (for summer lovers).

 

Somewhat downbeat personally though, in the very short term -- this coming weekend** looks very unlike next week for those preferring DRIER conditions. All lies in the detail still.

 

**Weekend counts as Thursday 15th to Monday 19th. Major last-big-festival-of-summer based driness/non muddiness needs for South Devon .... in my case ... I'm none too too optimistic ...

[MP-R]

2005 also in this neck of the woods.

[johnholmes]

'short wave' gawd the dreaded phrase from winter posts!

I assume folk mean the developing low pressure on all the models around T+144?

 

On another topic-the projected heat wave/spell which some are making a lot of, indeed it shows on the synoptic models. A word of caution. The anomaly charts do not show any strong signs of ridging, to some extent they all, ECMWF-GFS, NOAA, NAEFS all show the idea of a westerly flow out to about T+240 (10 days), two models show some sign of +ve anomalies, one does not, and none of them apart from ECMWF this morning show any real ridging at 500mb. Until this is shown on all the anomaly charts then at best it may be a short spell of extra warmth. Of course the synoptic models may have it better than the anomaly charts but I have to say that is rare, possibly very rare.

What causes me to hold off agreeing with heat wave is that there is no real agreement between the anomaly charts, 1 shows ridging developing (ECMWF), one does not (NOAA) and one is a sort of half way house between these two (GFS). The NAEFS, link below shows small height anomalies nothing more from about T+192 moving in from France and keeps these small anomalies out to the end of its run, increasing them slightly (about 16dm as far as I can judge from the chart at the bottom rhs).

 

http://www.meteociel.fr/modeles/naefs_cartes.php?ech=0&code=0&mode=0

 

and between me posting the chat and realising I had not posted the link it has updated, so the 12z issue is a bit different from the 00z (I assume it was the 00z?) and shows a bit more positive anomalies and earlier.

If the other anomaly charts changed that much on each run then I would be loathe to use them for doing any predicting. I'll take a look tomorrow at their next issue.

Edited August 13, 2013 by johnholmes

[J10]

Must have been 2003. June, July and not forgetting the first 10 days of August. All 3 months had good hot summer spells.

Probably right, 2006 has very good weather in June and July, but August was not so good.

[Captain Shortwave]

The shortwave is present on the 18Z too

 

Stark differences here with 12-14C uppers over the south, but rather wet and windy in the north

Until the models resolve this little low we won't know really how things are going to shape up. One thing for sure is that if the low does verify it will drag some very warm and humid air towards us.

[Tamara]

'short wave' gawd the dreaded phrase from winter posts!

I assume folk mean the developing low pressure on all the models around T+144?

 

On another topic-the projected heat wave/spell which some are making a lot of, indeed it shows on the synoptic models. A word of caution. The anomaly charts do not show any strong signs of ridging, to some extent they all, ECMWF-GFS, NOAA, NAEFS all show the idea of a westerly flow out to about T+240 (10 days), two models show some sign of +ve anomalies, one does not, and none of them apart from ECMWF this morning show any real ridging at 500mb. Until this is shown on all the anomaly charts then at best it may be a short spell of extra warmth. Of course the synoptic models may have it better than the anomaly charts but I have to say that is rare, possibly very rare.

What causes me to hold off agreeing with heat wave is that there is no real agreement between the anomaly charts, 1 shows ridging developing (ECMWF), one does not (NOAA) and one is a sort of half way house between these two (GFS). The NAEFS, link below shows small height anomalies nothing more from about T+192 moving in from France and keeps these small anomalies out to the end of its run, increasing them slightly (about 16dm as far as I can judge from the chart at the bottom rhs).

 

http://www.meteociel.fr/modeles/naefs_cartes.php?ech=0&code=0&mode=0

 

and between me posting the chat and realising I had not posted the link it has updated, so the 12z issue is a bit different from the 00z (I assume it was the 00z?) and shows a bit more positive anomalies and earlier.

If the other anomaly charts changed that much on each run then I would be loathe to use them for doing any predicting. I'll take a look tomorrow at their next issue.

I don't think the true emphasis has been on any heatwave though - it has simply been about the evolution to a late summer settled spell..with the possibility of some very warm weather later. Taking that into consideration then I think expectations have been sanguine enough  The definitively unsettled weather leaves soon enough early next week from southern uk but it looks like some northern parts may have to wait a little longer with fronts close by through next week. However the signal is good for a settled and increasingly warm spell of weather in the last third of the month, that, hopefully with time include the greater part of the BI  The signals are there and have been well covered without any further need this evening till fresh data appears tomorrow

Edited August 13, 2013 by Tamara Road

[Captain Shortwave]

Any bank holiday heat seekers, the GFS says the east coast of Greenland is for you!!! 

*note chart posted for amusement purposes only*

Edited August 13, 2013 by Captain shortwave

[draztik]

Gfs 18z looking less settled and less warm tonight in fi, compared to earlier runs..

support for a hot spell, seems to be slipping! Edit : tho if you ask me, that support was limited in any case.

Edited August 13, 2013 by draztik

[Tamara]

The shortwave is present on the 18Z too

 

Stark differences here with 12-14C uppers over the south, but rather wet and windy in the north

Until the models resolve this little low we won't know really how things are going to shape up. One thing for sure is that if the low does verify it will drag some very warm and humid air towards us.

I think that the micro detail at this range is obviously very unreliable and prone to exaggeration and inaccuracies  The larger scale UK suggestion is the possibility of a warm front getting stuck over the UK with warm and humid air to its south and cooler air to its north. But where this division boundary is a week away will be a mugs game let alone the problematics of a day ahead forecasting (if it occurs at all). Chances are the models will either over play the feature, it will disappear, or more likely (at least at this time) in terms of the suggested macro pattern, it will get adjusted further north westwards.

[The Northern Ramper]

We have the full set now going for the pressure rise from the south next week, excellent stuff

[Man With Beard]

One high pressure next week, but a multitude of options regarding heat:

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=306&y=141&ville=Londres 

 

 

Anything from Autumn to Egypt on that!

[shedhead]

GFS continues to advertise a slowly improving picture next week, but it's going to be the weekend before those across Scotland, N Ireland and the far north of England finally settle down. FI is of course FI, irrespective of what is shows, but for now a 4 or 5 day warm/very warm spell looks quite feasible.

 

ECM settles things down 24-48hrs quicker on a nationwide basis, but the little feature running in from the west could ensure a fair bit of midweek cloud, so it could again be Fri-Sat before sunshine becomes the predominate feature.

 

 

Overall confidence continues to firm up on a quiet, settled spell post T+168hrs, but there are still some big question marks over just how much sunshine we'll see and consequently how warm it becomes, before a possible Atlantic return for the final few days of official Summer.

 

Will be interesting to see if the 06GFS handles the little midweek feature in the same way as it did yesterday. 

Edited August 14, 2013 by shedhead

[Nick F]

Anyone who's looked at the synoptic charts for Saturday can see a distinctly autumnal flavour with that deep low scooting past northern Scotland  - in fact it looks like we're all in for a spell of wet 'n' windy weather by the end of the day:

 

00z ECM deterministic looking a little more robust with pressure/heights building across the UK by the end of next week, which would lead to some hot weather for the Bank Holiday Weekend. GFS flattens out any upper ridge fairly quickly, but surface pressure remains high across the south, so we may still gets some warmth building across England and Wales and it's looking pretty dry all week across the S and SE. Would be very wary for the north and far west though, as we may still see fronts grazing though here bringing cloud and rain at times.