Model Output Discussion 12z 23/05/13

[Frosty.]

http://www.meteociel.fr/cartes_obs/gens_display.php?x=306&y=141&run=12&ville=Londres&runpara=0&type=1&ext=1

 

And this link for the uppers - http://www.meteociel.fr/cartes_obs/gens_display.php?x=306&y=141&run=12&ville=Londres&runpara=0&type=5&ext=1

 

Looking like ECM is going to take the easterly route as well tonight

 

 

UKMO and GFS to compare at t144

 

These charts look so good for next week and it's now within the reliable (ish) timeframe, summer 2013 now looks like starting on a high note.

[Alex]

I'm afraid I have some less favourable news tonight, since the beginning of the year we have been in a positive AAM state, this in the last few days has turned negative which in turn could start to be signs of a la nina type developing, this is coupled with a weak MJO which for me is concerning longer term,

http://www.esrl.noaa.gov/psd/map/images/reanalysis/aam_total/gltotaam.sig.90day.gif

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml

The negative trend of AAM and a slightly favourable phase 1 MJO will help pressure rise over the UK over the next few days and I expect a decent first half of June maybe even with a thundery warm breakdown as progged by the GFS tonight but longer term I have concerns - the upstream patterns are starting to indicate a la nina type may be developing and recent summers have been spoilt by this. I just hope a upturn in AAM can help prevent this during the summer months.

Add me ln twitter at @alexbweather

Edited May 30, 2013 by Alex

[Summer Sun]

Could be some thundery downpours in the south and SE more settled the further north and west you are

 

Edited May 30, 2013 by Gavin.

[Barry12]

Could be some thundery downpours in the south and SE more settled the further north and west you are

 

 

Surely it would turn cooler?

[Summer Sun]

Surely it would turn cooler?

 

Uppers still remain around average thanks to a warming continent

 

Edited May 30, 2013 by Gavin.

[Frosty.]

One word describes this chart..........EPIC

[J10]

Indeed, this also evident on the pressure suite;

image.jpg

After a dry and settled start to next week, something more conducive to warm sunshine and scattered heavy showers/storms looking favourable, with SLP relaxing to average values of 1015mb - 1020mb across the south.

GFS Op FI looks to have developed any troughing too much, with something much shallower and average favoured amongst it's ensembles too.

 

A very good analysis there,the op run may well be right in picking a trend in slightly lower pressure pushing up from the south, allowing for some thundery outbreaks. I do think  there a possibility of a rinse and repeat pattern over the next couple of weeks.

 

The actual run though is very much at the outside extreme in terms of pressure and therefore rainfall, so in itself the detailed outcome shown in unlikely.

 

I have moved on to the latter period as the short term period pattern of High pressure ridging/moving North East seems likely.

 

ECM has come out and High Pressure looks more likely to be in control, but even here, low pressure towards the South East gives the potential for some heavy showers pushing up from the continent.

Could be some thundery downpours in the south and SE more settled the further north and west you are

 

 

Indeed definitely a possibility of a storm or two, perhaps something for everyone in tonight's run.

[Summer Sun]

The high keeps its grip on the UK at t240

 

Edited May 30, 2013 by Gavin.

[Frosty.]

The Ecm 12z looks nice and warm next week, a very anticyclonic start but then the high drifts northwest to become centred close to northwest scotland and that would mean that the northwest of the uk then has the sunniest and driest weather but other areas also remain warm or very warm and become more humid with sunny periods and a risk of thundery showers beyond midweek as pressure falls slightly but really this is a peach of a run from this weekend onwards with summery weather for all, really very summery charts dominate the 12z output this evening.

[Gibby]

Hi everyone. Here is my take on the 12 noon outputs issued by GFS, UKMO, GEM, NAVGEM and ECM for today Thursday My 30th 2013.

All models show High pressure steadily building NE towards the British Isles over the coming few days and over the weekend. Progressively drier and brighter conditions will develop from now on across the UK although conversely Northern Ireland and Scotland will see more cloudy weather with some light rain or afternoon heavy showers tomorrow and more cloud and light rain over the weekend.. It will be warm tomorrow over England and Wales and rather less so over the weekend as fresher air replaces the current humid air still covering England and Wales. There will be plenty of sunshine in average temperatures though to replace it. Early next week sees all models support the evolution of High pressure extending NE towards Scandinavia and an Easterly flow developing across Southern areas with the threat of showers rising here by midweek.

GFS then shows the slow but progressive fall in pressure continuing later next week with more and more showers in Southern Britain day to day. As we reach the weekend and FI some longer spells of potentially thundery rain are possible in the South extending further North. The end of the run then becomes cool and unsettled with showers or rain at times mixed with some brighter and drier spells.

The GFS Ensembles show a warmer spell to come as uppers rise above the June mean and persist that way for much of the two weeks. There is though a trend towards more unsettled conditions for Southern and Central areas with time with the driest conditions reserved for Scotland.

The Jet Stream shows the flow disrupting and becoming weak and diffuse before a split flow results in arms flowing North and South of the UK with a huge area of slack upper winds affecting much of Europe including the British Isles in a week or so.

UKMO tonight migrating North towards midweek with lower pressure gradually developing from the South. At this time point though the weather will still be dry and fine for all with some sunny spells with the warmest conditions developing in the West and North.

GEM shows a similar evolution moving on to take High pressure way to the NE of the UK. Pressure will fall steadily, especially in the South where Easterly winds would bring showers up from Europe and perhaps more general rain in the SW at the end of the run. While all this is going on in the South the North remains dry and pleasant with sunny spells and the best warmth in the West of Scotland.

NAVGEM shows the same pattern with showers developing from the South to the South from midweek.

ECM tonight also shows High pressure moving away North at the midweek point though maintaining a ridge down across the UK sufficient enough to keep most places dry through the week. It opts for High pressure South of Iceland late in it's run and the UK ridge is under pressure from the disturbance close to the East of England with the increasing threat of showers towards the weekend. Temperatures would be pleasantly warm in the sunshine though with a drift from the east for the middle and end of next week North Sea coasts would feel very fresh. Things though are generally on the decline by Day 10 as High pressure finally relinquishes it's grip.

In Summary all models show High pressure moving North of the UK later next week following several days of fine and warm weather with sunny spells. The net result of this is as I said this morning what happens to the weak disturbances caught on the underside of the High. GFS and GEM show a more substantial breakdown than ECM tonight but it wouldn't take much of a shift in any of the outputs to show either a wet South or a dry South and I think several more days of shifts and changes will occur before any concrete foundation can be put to any particular likely evolution so my advice is enjoy the guaranteed good weather over the weekend and early next week.

[Iceaxecrampon]

An absolute peach of a run from GFS tonight with some very warm maybe even hot air getting dragged into the SE

 

 

With a low tracking up from France there is the potential there for some torrential thunderstorms given the heat across the south

 

 

 

Of course at this it goes belly up further in FI

 

So familiar the last two charts for the similar weekend to one posted from the archives from 1982 - I always remember the "activity of that weekend" as I was out in it on a hot summer all night up to "no good"

 

Astonishing heat and convection around the 11th and 12th then in NW England - two direct strikes on the properties behind my parents - stir rod rainfall and thunder to burst your ears!

 

[049balt]

I'm afraid I have some less favourable news tonight, since the beginning of the year we have been in a positive AAM state, this in the last few days has turned negative which in turn could start to be signs of a la nina type developing, this is coupled with a weak MJO which for me is concerning longer term,

http://www.esrl.noaa.gov/psd/map/images/reanalysis/aam_total/gltotaam.sig.90day.gif

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml

The negative trend of AAM and a slightly favourable phase 1 MJO will help pressure rise over the UK over the next few days and I expect a decent first half of June maybe even with a thundery warm breakdown as progged by the GFS tonight but longer term I have concerns - the upstream patterns are starting to indicate a la nina type may be developing and recent summers have been spoilt by this. I just hope a upturn in AAM can help prevent this during the summer months.

This post is interesting, can anyone else add to what Alex has said?

[Frosty.]

The Gefs 12z mean looks even better than the 6z with more extensive azores ridging at times, it shows a generally warm and settled run which would contain a good deal of very strong sunshine and light winds, very blocked and summery pattern, after the dismal spring we have had, early summer looks more benign with high pressure all over the charts for a change, still need to watch out for some shallow weaknesses (troughs) but many areas are in for a good week of weather from tomorrow although the far northwest looks a little more unsettled until this weekend's high builds in, there are few things to resolve, the ecm 12z shows the high drifting to the northwest, most of the other 12z output shows the high migrating northeast, it implies the driest weather will be across northern britain and there is a risk of showers later next week but overall it's a big improvement on recent times.

[Carlrg]

Very pleasant rather than hot according to the 2m temps on the BOM.

 

http://www.meteociel.fr/modeles/bome_cartes.php?&ech=6&mode=8&carte=0

 

Combined with the 850's it will definately be what the doctor ordered.

 

http://www.meteociel.fr/modeles/bome_cartes.php?&ech=6&mode=1&carte=0

 

LP skirts Ireland and the West of Britain in the latter timeframes but gets pushed back into the Atlantic.

 

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

[East_England_Stormchaser91]

If you think end is already in sight for the high, you may possibly need to think again !

 

 

 

Could be seeing a big European heatwave similar to 2003 by looking at this! 

Look at them 20's racing across the med towards France and us ! Deep in FI i know, but this earlier on had the HP fade away. Instead, it has shown a reload from the SW to push over us and become a Euro/Scandi high with temperatures that should be mid to high 20's (80F+) easily.

Really quite awesome! (y)

Edited May 30, 2013 by East_England_Stormchaser91

[summer blizzard]

Oh baby, GFS18z just gets hotter and hotter.

 

[PB22]

Ooof, I'm glad I no longer live near the east coast, could be pretty cool and dull at times later next week IMO with that north-easterly flow:

 

http://www.wetterzentrale.de/pics/Rukm1441.html

 

Parts of Wales could be the best place to be next week.

 

Overall not a bad outlook and certainly a vast improvement on recent weeks, but that wouldn't be difficult.  Must admit thought that I'm not totally excited by the outlook from a warmth and sunshine point of view...I think some may end up pretty disappointed but having said that most places should at least get a couple of decent days out of this next week, and some will see a week of good weather, but beware those close to the east coast and that cold, cold North Sea...

[mushymanrob]

hmmm.... make the most of the nice weather mon-weds, after that it starts to become very uncertain as the high loses its grip. that pesky trough over denmark looks set to drift our way and spoil the sun/temps with heavy showers, some thundery.

 

theres no real sign that after the forthcoming sunny spell, there will be anything else. the ecm this morning goes messy (in fi), with no strong areas of high or low pressure.... i dont like messy synoptics. the gfs in fi is worrying, with a jet aimed straight at our southern regions, fireing in a succession of atlantic troughs with higher pressure over greenland.

 

summer might kick off on a nice note... but if concerns posted by alex last evening come to fruition and a la nina develops, summers could yet well be yet another washout.

[Frosty.]

Summer 2013 is going to hit the ground running, we have cross model agreement for high pressure to be slap bang on top of the uk during the early part of next week so a good supply of sun cream will be needed instead of those brollies and raincoats. We now have several days of nationwide pleasantly warm (trending warmer by the day) sunny days to look forward to until at least the middle of next week but eastern coasts will have cooling onshore breezes and a risk of sea mist/fog but sunny spells too, synoptically, we are looking at a very blocked set up next week, high pressure migrates slowly to the northwest and it's a huge area of high pressure which covers a large part of the atlantic so no lows will be coming from that direction, however, there are small shallow troughs embedded within this generally anticyclonic slack pattern which will promote the formation of heavy showers with hail & thunder where they occur but equally, if you avoid these pesky features, you should be in for a prolonged and warm settled spell, 

Edited May 31, 2013 by Frosty039

[ANYWEATHER]

hmmm.... make the most of the nice weather mon-weds, after that it starts to become very uncertain as the high loses its grip. that pesky trough over denmark looks set to drift our way and spoil the sun/temps with heavy showers, some thundery.

 

theres no real sign that after the forthcoming sunny spell, there will be anything else. the ecm this morning goes messy (in fi), with no strong areas of high or low pressure.... i dont like messy synoptics. the gfs in fi is worrying, with a jet aimed straight at our southern regions, fireing in a succession of atlantic troughs with higher pressure over greenland.

 

summer might kick off on a nice note... but if concerns posted by alex last evening come to fruition and a la nina develops, summers could yet well be yet another washout.

Yes the trends from both ecm and gfs shows low pressure developing to the south of the Uk, with high pressure yet again migrating to the north of the Uk, seems a familiar pattern now! Anyway, Im gonna enjoy some fairly typical Summer like weather, in the next few days, before the weather insults us again!  

[johnholmes]

It will depend on where you live in the 6-15 day time frame how warm and dry it will be.

The upper pattern is going to be different from what we have seen for so many weeks but with contour heihts higher to the north by then and lower elsewhere, then this will govern how long warm dry and fairly sunny you are. The output from the ECMWF-GFS this morning gives some indication of the rather complex upper pattern that may be around for the early part of June

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

How stable and long lasting this will be is not easy to judge. Other factors will come into play. How much effect the MJO may have on things is not easy to judge as various MJO predictions suggest it not being far from the origin. In my view that leaves using it as a guide to how the upper air may be as very suspect. The professionals suggest little risk of a change in ENSO but others on here suggest that may not be the case.

One thing seems fairly clear and that is that the start of summer is going to be a different one to last year. As PB has commented above close by the east coast is not the place to be for warmth and sun though either in the short term or perhaps longer until the sea starts to warm up from its rather low values (lower than average).

Overall there is little sign that the surface weather is going to slip back into the cold unsettled type of the past many weeks, unsettled for some with showery outbreaks and the occasional frontal input but also some warm sunshine at times for a good deal of the country. How warm and where/when the showery outbreaks is for the shorter term synoptic outputs.

Edited May 31, 2013 by johnholmes

[Gibby]

Good morning everyone. Here is the report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Friday May 31st 2013.

All models show complete agreement in the sequence of events synoptically and weather-wise over the next week or so making my job rather easier this morning. A slack Northerly flow over the UK exists at present under steadily rising pressure from the SW. Today will see bright weather as a result and with rather humid air over England and Wales still it will feel warm this afternoon. A weak front crossing Scotland could trigger an odd shower and will carry fresher air down over the UK tonight with lower temperatures than of late. The weekend then shows High pressure moving in over the UK by the end of Sunday with bright days with good sunny spells and cool nights for all. Early next week the High over the UK moves north with little change occurring though an Easterly drift to the wind will develop over the South by Tuesday. Through the remainder of the week all models support pulling the High pressure well to the North of the UK with a slack NE or East flow developing over the UK. Many places will remain dry but upper air features will become caught up in the airflow over the UK sufficient enough to promote the development of showers later in the week, these more likely towards the South.

GFS then moves through next weekend with one such feature drifting West over Scotland while pressure falls to the South of the UK too with more widespread rain or thundery showers edging up from the South over the weekend. Through FI today a more changeable pattern is apparent with some dry and bright days under a transient ridge before we end up back to square one to end the run with the UK under a slow moving trough with rain or showers at times and very average temperatures at best for June.

The GFS Ensembles have taken a step back this morning with most members now supporting very average temperatures over the coming weeks with little sign of any significant warmth. Nevertheless, a lot of dry weather is shown especially for the North. The South too shares this dry weather in the first week with a trend towards more unsettled conditions here from later next week indicating Low pressure moving up from the South or SW.

The Jet Stream falls light and insignificant to NW Europe over the coming days and that's how it stays for much of next week before a trend to set up an arm way to the NW between Iceland and Greenland is shown by the ensemble end.

UKMO is covered within the above text from the first paragraph.

GEM moves towards the end of next week and weekend with increasingly unsettled conditions developing, especially over the South with rain or showers very likely. The North would stay dry for the most part though even here a shower could not be ruled out later. Temperatures shown are close to average for all.

NAVGEM ends it's run with High pressure to the North and a strengthening Easterly flow developing as Low pressure deepens to the South of the UK replacing the otherwise showery conditions in the South with the threat of more persistent rain edging up from the South. The North would stay largely dry and bright with the warmest conditions in the NW. Elsewhere temperatures look like being close to average.

ECM today shows a very complex slack pressure pattern over the UK late next week and through the weekend. In essence the weather would be characterized by a lot of dry and benign weather conditions with plenty of bright weather around but with the ever increasing risk of showers from midweek as upper air disturbances become embroiled in the slack airflow pattern. Late in the run a more marked breakdown with Low pressure is shown moving it's way North towards Southern Britain from Spain.

In Summary this morning we have universal agreement that the weather will be set fair for the next 5 days or so with plenty of dry and pleasant weather with warm sunny spells and light winds. Night temperatures will be rather chilly and day temperatures will be near to average for many. From midweek there is good support this morning for pressure to leak away over the UK with the increased threat of showers and probably longer spells of rain to the South later as Low pressure pushes up from the South ala GFS, GEM and ECM. However, despite this talk of rain many places will continue with 'OK' weather between any showers but those wanting a heatwave I'm afraid there is little evidence of that this morning, none more so when looking at the GFS Ensembles. What is apparent if these charts verify UKMO mid term outlook yesterday made a good call on their forecast and I expect it to be further backed up today on it's usual Friday more comprehensive outlook.

[Purga]

Cool over the weekend then average temps and dry for the first part of next week looks consistent and it will be pretty pleasant for most.

Towards the end of next week the temps remain about right for June and the threat of more unsettled conditions increases

 

Pretty much as has been shown for some time. A pleasant spell coming up then a mixed bag.

My METO iphone App is showing today as the warmest down here in the south (19C) and with temps at max 15/16C and quite sunny for the next 5 days. Very nice!

Edited May 31, 2013 by Purga

[Costa Del Fal]

Yes the trends from both ecm and gfs shows low pressure developing to the south of the Uk, with high pressure yet again migrating to the north of the Uk, seems a familiar pattern now! Anyway, Im gonna enjoy some fairly typical Summer like weather, in the next few days, before the weather insults us again!  

Very pessimistic post. On the whole I think theres a fair few more than a 'few' days of fine weather. Maybe a few showers next week but it seems clear to me that unless theres a fat 1030mb high constantly over the country you will never be happy. The Gfs 00z Op was an outlier for pressure at the end too with all members and even the control going for higher pressure. I recommend all members take a look at the ensembles before posting misleading comments.

[bringmesunshine]

Seems that (to some) anyone seeing a spell of fine weather in FI is 'hopecasting', while the showery breakdown at the end of next week is a nailed on cert.