Model Output Discussion 12z 10/05/13

[NeilN]

Was that the June it snowed? I see to remember May/June 1991 as ropey....then a warm summer.

It will pick up I am confident.

[Carlrg]

After the cold pool passes through on the 16th the BOM drags in a slighly warmer Easterly. This Is the best for the warm lovers I can find but overall not great. Unfortunately It looks like another rinse and repeat at 240h +.

 

http://www.meteociel.fr/modeles/bome_cartes.php?&ech=6&mode=0&carte=0

Edited May 10, 2013 by Carlrg

[Panayiotis]

Another poor GFS run with the best charts I could find is for the SE where some warm-ish uppers clip the area:

 

Would probably feel decent if there is any sunshine but I doubt it with the center of the more or less over that region, with heavy, thundery downpours likely along with the rest of the British Isles:

Edited May 10, 2013 by Panayiotis

[JP1972]

Was that the June it snowed? I see to remember May/June 1991 as ropey....then a warm summer.

It will pick up I am confident.

 

It will "pick up" based on what?

 

The last few springs have been average followed by very average summers, if not very wet.

[Fozfoster]

It will "pick up" based on what?

 

The last few springs have been average followed by very average summers, if not very wet.

Glass still half empty. JP :-)

[summer blizzard]

Still looking to day 15-20 (25th May onward) for a pressure build to the north and east of the UK in my opinion for any attempt at warmth.

 

At least the Jet Stream is pretty weak though, just in the wrong place.

[johnholmes]

Was that the June it snowed? I see to remember May/June 1991 as ropey....then a warm summer.

It will pick up I am confident.

yes it stopped cricket at Buxton, mind you the town is around 1,000ft.

In Manchester day maxes went from 6-7C to 25C in either 5 or 7 days I cannot remember which and yes the summer was often hot in the Manchester area.

[Gibby]

Good morning. Here is the report on the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Saturday May 11th 2013.

All models show a cool and changeable weekend with sunny spells and outbreaks of rain and showrs moving Eastwards across the UK periodically. It will be generally on the cool side. Some of the showers will be heavy especially towards the East today. The best of the dry weather will be in the West later today and tonight and in the East tomorrow. Through the early days of next week a new Low pressure drifts down from the NW with further rain and showers for all with a more prolonged spell of rain likely in the SE by midweek while some of the showers elsewhere may be heavy and thundery.

GFS then shows towards the end of the week the winds change to a NE feed as the Low pressure sink away to the SE with cool and cloudy weather with occasional rain or showers occurring for all areas at times. This weather extends through the weekend too with winds backing Northerly then NW and eventually back to Westerly through FI around a deep Low to the NW of Britain. It would become somewhat less cool in a Westerly breeze but changeable weather would be maintained though the South might become drier and less cold for a time before the whole Low pressure area slides back Douth with an Easterly unsettled feed setting up again with a High pressure block to the North keeping Northern areas drier then.

The GFS Ensembles show a continuation of the cool and unsettled spell through the two weeks with suppressed temperatures and spells of rain and showers in just broef drier and bright interludes.

The Jet Stream flow shows the split flow continuing for a time with the northern arm extending South of the British Isles towards Southern Europe with the Western end of the Northern arm then weakening and dissolving leaving just a portion of the flow remaining near Spain and North Africa later next week and weekend.

UKMO today shows slack Low pressure over and near to the SE and NW of the UK with unsettled conditions continuing with rain or showers at times and quite cool conditions too outside of any sunshine.

GEM today shows a very unsettled end to the week and weekend too as Low pressure refuses to give ground once it sinks over the UK through the week and is reinforced by a new centre close to the North over next weekend keeping the showery and unsettled theme going.

NAVGEM continues to show the Low sinking South of the UK later next week with an Easterly or NE flow developing with the rain and showers concentrating more towards the South by next weekend with longer drier if cool spells in the North with some sunshine.

ECM finally maintains it's cool and unsettled feel still today with Low pressure never far away from UK over the next week to 10 days with rain and showers for all areas in cyclonic windflow patterns. Temperatures would often be suppressed but it could feel OK in any sunshine. Towards the end of the run the Lo centres drift to the East setting up a cool Northerly with showers though pressure is building slowly in from the NW

In Summary today the weather will remain often cool and showery over the next 10-14 days as a UK trough continues to be the form horse over the period. As always in slack low pressure some areas will see some lengthy dry and bright spells and wonder what all the fuss is about while others see more than their share of often heavy and persistent showers or more prolonged rain. However, nowhere would be guaranteed to stay dry for too long under such synoptics with the impression from the distant output that we may remain in this rut for a while beyond the end of the output range this morning.

Footnote: For those wanting to view my forecast pages within my website today will notice they are not updated this morning. My web Host appears to be down across their entire website this morning meaning I can't update so sorry for that. Access to the site and the Live portions of the site are all updating ing fine though. Hopefully will be OK for this evening though.

[Frosty.]

We are still on course for a warmer spell in late may with higher pressure according to the Gefs 00z mean and the Gfs 00z op run in FI but it looks like the current cool and unsettled spell will persist for the next few weeks with sunshine and heavy showers being the main weather type but add to that occasional persistent rain and stronger winds with temperatures struggling in the low to mid teens celsius, the one saving grace is the sun is so high and strong so in any sunny periods it will feel pleasantly warm. The coolest weather looks like being the middle of next week according to the gefs mean, thereafter, the upper air (T850 hPa) slowly warms but we remain showery with the trough remaining in situ but slowly filling and drifting slowly away to the west/northwest along with the polar front jet retrogressing towards greenland. The form horse beyond T+240 hours is for the formation of a large scandinavian anticyclone which will be influencing our weather through the last 7-10 days of may and hopefully into june whilst pressure looks low across Greenland but the gfs 00z shows high pressure in that region for a while although the op run bears no resemblance to how the gefs 00z mean evolves.

 

In summary, a generally  showery/cool cyclonic spell for the next 10-12 days and then trending drier and warmer (in my opinion)

Edited May 11, 2013 by Frosty039

[johnholmes]

I think you may be a bit premature with your timing frosty, at least according to the anomaly charts. Out to about 24 May they really show little sign of the trough shifting enough and the upper ridge in the Scandinavia region building west sufficiently,to give the dry and warmth that you suggest the GEFS mean is showing.

Personally I would back the anomaly charts but I suspect that by the end of May the upper ridging will be starting to have more influence than the trough. Just how much of a warm up that causes is still open to doubt.

[Frosty.]

I think you may be a bit premature with your timing frosty, at least according to the anomaly charts. Out to about 24 May they really show little sign of the trough shifting enough and the upper ridge in the Scandinavia region building west sufficiently,to give the dry and warmth that you suggest the GEFS mean is showing.

Personally I would back the anomaly charts but I suspect that by the end of May the upper ridging will be starting to have more influence than the trough. Just how much of a warm up that causes is still open to doubt.

Hi John,

 

Yes I think I was being too optimistic there but I still think there are encouraging signs of a more sustained pressure rise towards the end of the month and for rather warmer weather to become established but a generally cool and unsettled couple of weeks ahead with just the occasional fine day here and there, today and most of next week look very showery with hail and thunder on most days.

[Purga]

I think you may be a bit premature with your timing frosty, at least according to the anomaly charts. Out to about 24 May they really show little sign of the trough shifting enough and the upper ridge in the Scandinavia region building west sufficiently,to give the dry and warmth that you suggest the GEFS mean is showing.

Personally I would back the anomaly charts but I suspect that by the end of May the upper ridging will be starting to have more influence than the trough. Just how much of a warm up that causes is still open to doubt.

Absolutely - there is no sign of any real or prolonged warm and dry weather from the anomoly mean charts.

GFS ENS show some very wet solutions and average or cool temps for the forseeable future

 

 

If the upper air temps do rise it looks like being accompanied by a lot of rain so it will remain cool at the 2M level.

[Frosty.]

Absolutely - there is no sign of any real or prolonged warm and dry weather from the anomoly mean charts.

GFS ENS show some very wet solutions and average or cool temps for the forseeable future

 

 

If the upper air temps do rise it looks like being accompanied by a lot of rain so it will remain cool at the 2M level.

I don't think it's as bad as you suggest, yes it's a sunshine and heavy showers outlook which is a very interesting weather type and something we mostly missed out on in april due to it being so cold and easterly dominated. And there is hope of a warmer and more settled end to may.

Edited May 11, 2013 by Frosty039

[johnholmes]

I do find it amusing that two folk comment on one post from someone else and see different things from it?

I've been stuck in front of this machine for 90 mins trying to get Prom tickets. I'll take a break and come back and show the charts I was commenting on then everyone will know what I based my remarks on.

Edited May 11, 2013 by johnholmes

[Iceaxecrampon]

I do find it amusing that two folk comment on one post from someone else and see different things from it?

I've been stuck in front of this machine for 90 mins trying to get Prom tickets. I'll take a break and come back and show the charts I was commenting on then everyone will know what I based my remarks on.

 

Prom Tickets...

 

When the Proms are on it always remind me that summer is over.

 

Ooops!  - shouldn't mention that on here.

 

Feels like it today CH nearly went on up here.

 

Ian

[Frosty.]

Summery weather arrives a few days before the official meteorological start of summer on the Gfs 06z with a strong scandi high and warm continental SE'ly winds covering the uk, the cool trough finally out of the way to the northwest by then. Overall, the 6z is not bad, yes we have a very unsettled and showery spell as we head towards the middle of next week which seems to be the peak period of the showery activity, it begins to wane beyond midweek but a risk of some heavy rain in the southeast later next week but trending drier and brighter for other areas. Then as an atlantic ridge topples southeastwards next weekend, saturday looks fine and warmer but by next sunday the ridge is subsiding quickly and another unsettled and cooler spell is incoming for the following week with rain followed by sunshine and showers and cold enough for ground frosts in the north, but then the azores anticyclone begins to ridge northeast towards and then across the uk and at the same time, the scandi high is finally forming so there are good signs looking ahead to late may with warm and anticyclonic weather eventually gaining the upper hand.

 

Tomorrow looks a nicer day in the far east of the uk with a mainly dry day with sunny spells and temps up to 15c, cooler and more unsettled for the western side of the uk with rain spreading east, eventually the rain spreading to all areas by tomorrow evening/overnight.

[johnholmes]

my take on the 500mb anomaly charts, copied into the other thread as well

anomaly charts as of sat 11 may 2013 their view.pdf

[Purga]

my take on the 500mb anomaly charts, copied into the other thread as well

anomaly charts as of sat 11 may 2013 their view.pdf

Great analysis again John, thanks.

So very much underlining the cool temps and mean trough (wet / damp) theme set to dominate the UK for much of the next 2 weeks.

May CET is running a tad +ve atm but could we be heading towards yet another -ve CET for May?

[Frosty.]

Great analysis again John, thanks.

So very much underlining the cool temps and mean trough (wet / damp) theme set to dominate the UK for much of the next 2 weeks.

May CET is running a tad +ve atm but could we be heading towards yet another -ve CET for May?

Why are you accentuating the negatives when there is also expected to be some nice pleasant sunny spells at times despite the showery outlook?

 

The models could be a lot worse, I can see a mixed outlook with high pressure ridging across from time to time and some unsettled spells just like the 6z shows, even the latest met office update offers some fine spells between the showers/thundery rain and a warming fine trend for the south later.

Edited May 11, 2013 by Frosty039

[legritter]

Hello gang ,Certainly not boring weather on the horizon going by charts but some would certainly love a long warm spell especially those in weather sensitive jobs especially the british holiday sector .i certainly would not want to bet past day 10 ,certainly one to watch past midweek and where that boundary of different air masses sets up along with an increasing stronger sun things could get very interesting .remember all those mild very windy winters over a period of say 18 /20 yrs well its certainly changed now and summers seem to be running in a string of similar fashion .its a very hard Nut to crack the reason why and although its possibly some sort of cycle its the cause which is very interesting for us weather watchers .once again the Fax charts should make interesting discussion as we approach next weeks possible clash of different air masses .

[Methuselah]

Great analysis again John, thanks.

So very much underlining the cool temps and mean trough (wet / damp) theme set to dominate the UK for much of the next 2 weeks.

May CET is running a tad +ve atm but could we be heading towards yet another -ve CET for May?

Not quite sure where you get the 'wet/damp' theme from...It looks like a typical sunshine & showers mix, to me. Which, if you're interested in growing things, hardly seems catastrophic.

[Frosty.]

Not quite sure where you get the 'wet/damp' theme from...It looks like a typical sunshine & showers mix, to me. Which, if you're interested in growing things, hardly seems catastrophic.

Agreed, it's good weather for gardeners and growers, a tad cool but pleasantly warm in any prolonged sunshine and a good mix of weather for everyone.

[rory o gorman]

The potent trough over southern Ireland on Wednesday is looking increasingly good for a first proper chase this season. ECM showing signs of the western ridge having more of an influence out into F.I so not to displeased with latest outcome personally.

[Nick_W]

Why are you accentuating the negatives when there is also expected to be some nice pleasant sunny spells at times despite the showery outlook?

 

The models could be a lot worse, I can see a mixed outlook with high pressure ridging across from time to time and some unsettled spells just like the 6z shows, even the latest met office update offers some fine spells between the showers/thundery rain and a warming fine trend for the south later.

 

Because he is a t w a t.

[IDO]

Agreed, it's good weather for gardeners and growers, a tad cool but pleasantly warm in any prolonged sunshine and a good mix of weather for everyone.

Quite. The 500mb anomaly charts give us a synoptic pattern but are not always great for surface conditions. The trough next week has been modeled mostly to be a weakening affair, with little renewed energy coming from the NW, so not seeming to provide further frontal/low based precipitation, after the initial sinking. If that is the case, we should see the AH help to dampen that flow (from Greenland), with some attempted ridging from the SW/W.

The 12z highlights this in the next 8 days, with some average, to warm feeling days, that is, inbetween the showers:

Thursday: Friday:

Sat: Sunday:

Tuesday and Wednesday look the wet ones, as the low is dragged down the BI.

The following week (D9+) does indeed look cooler and wetter at the moment, but there is time for this to also improve.

Edited May 11, 2013 by i'm dreaming of...