Model Output Discussion 12z 10/05/13

[Milhouse]

ECM still liking its deep low pressure.

 

[Frosty.]

The Ecm 12z shows a narrow ridge of high pressure building in from the west on saturday so at least half of the weekend would be fine, sunday is nasty though, NE'ly gales and heavy rain. So, we have the gfs 12z showing a weak ridge for next weekend which would make it a fine weekend apart from a few showers and the ecm which starts fine and high pressure is close to the west and northwest which would bode well for the following week, and the ecm for T+192 looks allwhite to me.

[Summer Sun]

Associated with that low next weekend could be an area of fairly warm uppers in the East

 

 

For some reason ECM on wetterzentral here is showing something totally different to meteociel

 

 

EDIT

 

Its now sorted its self out all is correct again

Edited May 12, 2013 by Gavin.

[Frosty.]

Folk in the north and west of the uk will love the Ecm 12z in FI with high pressure slowly pushing southeast and  warmer, fine and sunny weather at long last after weeks of strong cool winds and rain, for the southeast of the uk it's cool and unsettled but slowly improving, this run in FI is chalk and cheese compared to the 00z. Beyond T+240 it would be an early start to summer.

[Gibby]

Good evening. Here is tonight's assessment of the 12 noon output of GFS, UKMO, GEM, NAVGEM and ECM for today Sunday May 12th 2013.

The pattern for this week has long been resolved with Low pressure sinking South over the UK with rain and showers for all in generally cool or rather cool conditions. Later in the week the isobars open out over the UK meaning lighter winds and slow moving showers and possibly more prolonged heavy rain in the SE.

GFS then shows a steady but slow improvement starting in the SW and gradually working it's way slowly North and East over the UK, eroding away at the unstable NW flow covering the UK with further rain and showers. By the middle of the second week pressure has built markedly to form a UK based High which steadily moves East sucking up increasingly warm conditions over the UK with sunny spells. Most of the UK is then dry towards the end of the run with no more than the risk of a thundery shower in the SW for a time.

The GFS Ensembles show much improvement tonight with warmer air progressively taking control over our weather, particularly in the second week. After frequent outbreaks of rain in the first week the second week sees progressively drier conditions slowly take control.

The Jet Stream shows a deep troughing of the flow over the UK this coming week before the pattern collapses and the Jet stream becomes split with a flow East over Africa and a very weak Northern arm blowing into Northern Scotland from the West in a week or so.

UKMO continues to keep Low pressure near to the UK to start next weekend, centred over Germany with a Northerly flow over the nation with further showers and cool conditions especially near the East coast. The NW would see the brightest and driest conditions.

GEM tonight has a slight improvement too over recent output showing a trend towards ridging from the Azores High for a time next weekend. However, the trend is a slow one and a temporary one with scope for further showers over the UK until the end of the run at least as a slack Low pressure area from the North regains some control over the UK weather.

NAVGEM maintains broadly unsettled conditions over the end of it's run with winds based from between West and North with further rain and showers at times in generally chilly conditions.

ECM tonight shows a showery end to the week followed by a nasty Low pressure deepening over Germany and moving West to Holland on Sunday with a cold and very wet day for many Southern and Eastern areas in a strong Northerly wind. The North and West would see the best of a bad day with less rainy and less cold conditions though still windy. Towards the end of the run the drier NW will extend it's weather steadily South over the UK as pressure builds strongly to the North and the offending inclement Low slides SW then South over France with an Easterly flow blowing over England and Wales still with scattered showers. The run ends with the slow improvement continuing with any remaining showers restricted to the SE while East coastal counties stay rather chilly with an onshore breeze. Some warm sunny spells would develop in the North and West.

In Summary tonight there are slender signs of improvement, notably from GFS and it's Ensembles as warmer conditions are well supported with time. There is still a lot of room for improvement between the other models and ECM becomes notably unpleasant next weekend before pressure builds down from the North in the second week with more promising synoptics developing as the run ends. It's too early to say whether tonight's embryonic improvements are likely to be sustained and expanded upon but there is definitely room for some optimism tonight as we move towards the end of the month.

[ANYWEATHER]

Its looking more like Autumn then late Spring! Out to t+168 ecm and gfs differ greatly! Gfs shows more of a kinder weather pattern, Ecm  shows some nasty weather conditions for the southern half of the Uk in picticular. All I have to say with this set-up is that I feel I when Im sitting in my chair looking at the models[ despite FI predictions ]

is a case of "de ja vu" last years model predictions look a lot like  they do now! Would love some nice weather for all, but cannot see anyway out at the moment, but of course in these scenarios, some folk do better than another...!  

[Frosty.]

Its looking more like Autumn then late Spring! Out to t+168 ecm and gfs differ greatly! Gfs shows more of a kinder weather pattern, Ecm  shows some nasty weather conditions for the southern half of the Uk in picticular. All I have to say with this set-up is that I feel I when Im sitting in my chair looking at the models[ despite FI predictions ]

is a case of "de ja vu" last years model predictions look a lot like  they do now! Would love some nice weather for all, but cannot see anyway out at the moment, but of course in these scenarios, some folk do better than another...!  

It's true the good weather is in FI but there is increasing ensemble support for a fine and warm spell close to the end of may, the met office are also predicting a marked improvement towards months end so it's not just pie in the sky, it has substance.

[ANYWEATHER]

It's true the good weather is in FI but there is increasing ensemble support for a fine and warm spell close to the end of may, the met office are also predicting a marked improvement towards months end so it's not just pie in the sky, it has substance.

Well the met=office  predictions flutter all over the place, and the ensemble support is something ,but Ive seen this synoptic situation time and time over again! With respect  to you Frosty,I hope youre right, I want to air that damn tent and have a good few days in it!  

[William of Walworth]

Our first outing for the tent is next weekend -- Thursday to Monday, Derby! (yes the festival season is about to start for us).

From very recent output, I'm REALLY struggling to predict whether we get a cold and shower dominated weekend or a slightly warmer and less wet one. Models seem all over the place right now.

Keen model watching the way forward, as for everyone. Detail is ever changing right now.

Edited May 12, 2013 by William of Walworth

[Summer Sun]

Not bad at all from the ECM ensemble a steady rise in pressure as we move towards 10 day

 

 

GFS ENS and ECM at t240 (day 10)

 

Edited May 12, 2013 by Gavin.

[Tamara]

Well the Azores/Scandinavian ridging is illustrated well on tonights ECM by day 10, but rather earlier than suggested this morning, though taking into account the agreement in trend with the GFS for this sort of change further down the line than it might have some merit - albeit perhaps a bit too progressive with the trend. However hopefully signs of things changing for the better tentatively emerging as we get towards the end of May In the meantime however there is a week to 10 days + of potential downpours to get through and the ECM still wants to make quite a lot of the continental low close to the east and south east next weekend. 

[Guest pjl20101]

Judging by the CPC 8-14 day chart it looks like the menacing trough that was going to be a main feature of the weather is starting to weaken now with a hp influence from the ne bulldozing in to our shores and becoming more evident too:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

Looking very encouraging for a possible pattern change then and like what matt Hugo said on twitter of getting out of the +nao pattern.

[AWD]

A rather notable depression for mid May on the UKMO 0z raw output this morning for Sunday;

Would certainly be a few tree related issues if that verified. GFS 0z has it further east over the continent however, with the UK under slack showery conditions next weekend.

[mountain shadow]

GFS 0z horrendous for any dry Spring warmth.

Unsettled throughout with the British Isles stuck under à mean trough due to extensive blocking to the North.

[mushymanrob]

well... the ecm this morning suggests a gradual improvement towards drier, warmer, sunnier, calmer weather over the next 7-8 days, becoming pleasant early next week. this mornings gfs 00z is having none of it, keeping us in a cooler unsettled regime.

 

meanwhile theres several cool showery days to endure with some very heavy and persistent rain tues - wedns morn for southern areas.

[Jezzer]

Matt Hugo's latest tweet backs up the potential for a rise in pressure later in the month...

 

 

"The consistency is growing for a pressure rise later in the month as again illustrated by latest GEFS 00z" courtesy of @MattHugo81

 

[johnholmes]

Judging by the CPC 8-14 day chart it looks like the menacing trough that was going to be a main feature of the weather is starting to weaken now with a hp influence from the ne bulldozing in to our shores and becoming more evident too:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

Looking very encouraging for a possible pattern change then and like what matt Hugo said on twitter of getting out of the +nao pattern.

If only it were that simple!

The 6-10 and 8-14 were fairly different but reasonably consistent in changes over that time scale. The 8-14 as above did show less signs of the trough and some indication of the upper ridge edging westwards. However it is too early to be sure this is going to happen.

The ECMWF-GFS this morning, see link below, is so different, on either model, to what they showed previously that considerable caution is required as to what the upper air pattern will be 6-15 days from now let alone making assumptions about the surface pattern.

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

the post from mushy indicating differences between GFS and ECMWF is indicative of the uncertainty in the models as to just what is likely to happen beyond about 5-6 days and more so the further out we go.

Edited May 13, 2013 by johnholmes

[Frosty.]

The GEFS 00z mean is looking very encouraging again this morning with the Azores anticyclone becoming a major feature for the uk by early next week, also the ECM 00z is trending towards a much warmer and settled azores high dominated outlook, some very nice charts to start the day.

[Gibby]

Good morning everyone. here is my report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Monday May 13th 2013.

All models maintain the theme of this week that has been shown for many runs now. An unsettled week ahead looks likely with Low pressure slipping South over the UK exacerbated by a disturbance running East into Southern Britain tomorrow bringing showers and in the South a particularly wet day tomorrow. By Wednesday Low pressure will be centred over the UK with a mix of sunshine and scattered heavy showers over the UK though some parts as always in showery setups may miss them and see a lot of dry and reasonable weather. By Friday Low pressure will be more likely centred to the South or SE of Britain and developments from their may bring some thundery rain NW across Southern and Eastern Britain to set us up for a cool and breezy northerly flow at the weekend with further showers or rain at times.

GFS then moves us into next week with a NW flow, so still staying on the cool side with further showers running down in the flow, particularly to the North and West where some longer spells of rain are possible, close to Low pressure to the NW. Unfortunately this morning the improvements of last night are muted from GFS with slack Low pressure maintained near to the UK with further rain at times right out to the end of the run.

The GFS Ensembles today although a slight step back from last night still show some signs of optimism as the trend is still upwards, especially later in the run with rainfall amounts reducing with time. The operational was a cold outlier late in the run over Northern locations.

The Jet Stream shows the anticipated trough in the flow developing over the UK through the week. Then we will see the trough disrupt and decay as a split flow develops again with the Southern arm well South near North Africa while a Northern arm moving East or NE just to the north of the UK in a week's time.

UKMO today has a deep Low over the Southern North Sea on Sunday with a chilly Northerly flow over the UK. It will be a cloudy and windy spell with very cool conditions too with cloud and outbreaks of rain scattered around over the UK, perhaps heavy and prolonged towards the East.

GEM today shows the low pressure further East over Germany at the weekend with a NW flow down over the UK with showers likely. It then draws further Low pressure down towards the Northern North Sea with further rain and showers likely well into next week.

NAVGEM is trying hard to get improvements into the UK with the help of the Azores High ridging towards Scotland late next weekend and into the following week. However, it is a slow trend and Low pressure remains stubbornly close over the near Continent maintaining a chilly feed of air down from the North with showers in the East lasting well into next week.

ECM is the pick of the bunch today with High pressure ridging strongly NE from the Azores early next week removing the chilly and showery conditions with dry and increasingly warm conditions especially in the west. By the end of the run High pressure has total control of the UK weather centred close to the NW with some very warm temperatures possible here by midweek next week. Further South and East there will also be some dry and settled weather but here Eastern coasts would become cool and grey with low cloud lapping in off the North Sea which could move SW in the flow over much of Southern Britain each night, burning back slowly through each day.

In Summary there are mixed messages again from the outputs this morning. After an unsettled week agreed upon by all output this week there are various options on the table this morning. GFS, GEM and UKMO look like there would be a slow road to improvements in the weather next week which may be scuppered by further developments from the NW. However, NAVGEM and more especially ECM bring the Azores High towards the UK breaking us out of the pattern of cool and showery weather with some welcome sunny weather especially in the NW although I doubt Eastern Coastal Counties would be clapping their hands at the prospect of a spell of NE winds under an anticyclone this early in the season.

[Summer Sun]

Good to see ECM sticking to its guns this morning by rising pressure early next week once the unusually deep low from Germany clears away back into eastern Europe

 

 

All in all a very positive run from ECM again this morning and its one that has ensemble support which is even better

 

 

Edited May 13, 2013 by Gavin.

[Weather Boy]

A rather notable depression for mid May on the UKMO 0z raw output this morning for Sunday;

image.jpg

Would certainly be a few tree related issues if that verified. GFS 0z has it further east over the continent however, with the UK under slack showery conditions next weekend.

 

 

Hmmmm, speaking as someone who is going to Lords for the cricket on Sunday, this certainly caught my eye as being of interest.

 

Looking at the other models, it seems that there is good agreement for LP to our east at that point.  These are the two latest runs of the ECM:

 

 

 

 

 

And the GFS:

 

 

 

Whoops, got those charts in the wrong order, but I'm sure you can see for yourself.

 

Looking on the bright side, it seems that neither of these two agree with such an aggressive and unpleasant stance as provided for by UKMO which would probably provide for a washout or at least very adverse weather conditions.  However, that is looking on the bright side ad the models seem agreed on a cold and unsettled day just wrong for cricket - with EA and the SE being the worst place in the country to be.  However, if ECM and GFS were right, then I would imagine that would translate into heavy showers rather than a total washout.

 

Oh, well, there is always the pub!

 

Longer term, it seems to me that the long term signals have favoured a rise in pressure in the latter 1/3 or at least last week of the month and that prognosis seems to be gathering pace.  A bit early to be lighting the BBQ though - it could all change!  But my instinct says not, as a general trend.

[TonyH]

I am wondering with what Gavin partridge our friend has thought about this week? As I've not visited gavsweathervids.com recently.

You could just visit?

[Bobby]

Potentially some very wet weather this week on the 06z GFS and UKMO, first tomorrow from an area of heavy rain for the S/Central areas from a developing wave moving up from the SW and then later in the week as an energetic low moves in from the E spreading more heavy rain across the country. Potentially some flooding issues? The rain looks fairly intense although the second event is uncertain, models unsure on that one.

 

GFS rainfall accumulations by the weekend

 

Edited May 13, 2013 by Bobby

[johnholmes]

Certainly an interesting 24 hours coming up with marked changes from UK Met as to how they treat the lows approaching the SW during tomorrow.

See the various options on this link using either the current ideas T+00 at 06 and T+ etc

Or go to the previous chart say for Sunday and click on the forecast postions/depths etc

http://www.weathercharts.org/ukmomslp.htm#t24

I would not be surprised to them issue some rainfall total warnings based on their latest Fax charts with considerable deepening predicted. Currently the latest movie sat picc has not even got any sign,see below

http://www.yr.no/satellitt/europa_animasjon.html

Looking at the upper air for 500mb 06z actual see link

http://www.netweather.tv/secure/cgi-bin/premium.pl?action=gfs;sess=decd4ac5414597102ae791130d23bc05

again not much to go on there but the jetstream chart link below gives a better idea

http://www.netweather.tv/secure/cgi-bin/premium.pl?action=gfs;sess=decd4ac5414597102ae791130d23bc05

if you move it on 6-12 hours one can see the change in the flow with the surface feature predicted (on GFS and it seems a reasonable match to what UK Met are probably seeing) forming as the jet breaks down briefly with the surface feature just ahead of it and then running ahead of the rear jet, almost at its left exit, a classic area for deepening.

So well worth watching for interesting meteorology in the next 24-36 hours

John

Edited May 13, 2013 by johnholmes

[Frosty.]

The Gfs 06z shows a reversal of fortunes next weekend with the north and west of the uk having a fine spell for a change with lots of sunshine and temperatures around average, the south and east look much cooler and very unsettled with wet and windy conditions which only slowly eases but by early next week, the large and strong azores ridge to the n and w slowly topples further southeast so most of the uk becomes fine for a time and temperatures recovering in the s and e to average or slightly above. The azores anticyclone continues to feature throughout FI but the 6z is not finished with cool troughs yet and the uk becomes cooler and more unsettled for a while but then later in FI a strong azores high throws another ridge northeastwards but this time, much further to the south and east which means we end up with the usual northwest-southeast split with the warmest and sunniest weather for southern and eastern parts of the uk with temperatures close to 20c but the north and west of britain, especially scotland and n.ireland become affected by atlantic low pressure once again, still, it looks like a more level playing field at last with the chances of a more anticyclonic outlook looking increasingly good, especially when you look at the latest ecm 00z ens mean and gefs mean.