Jump to content

Model Output Discussion 31/05/14 onwards.


Recommended Posts

  • Replies 1.1k
  • Created
  • Last Reply

Top Posters In This Topic

ECM ens keep high pressure to the south west of the uk, though the ridge keeping most of the UK dry until week 2 when there are signs of the high moving west, usual caveats apply though.

Posted Image

Posted Image

 

This week looks rather warm, though there could be cloud issues towards the end of the week as a tropical maritime flow establishes itself with a very large sea track coming over the top of the Azores high.

Edited by Captain shortwave
  • Like 1
Link to post
Share on other sites

well the 06z gfs in fi is pretty dire, about as poor as it can get with the expected high retreating westwards and allowing a miserable cool low pressure to dominate our weather from the east....

 

but its fi....

Link to post
Share on other sites

It is dire, but it's so dire, I'm finding it hard to believe. Ive noted the GFS has tried to pull off a few of these 'almost record breaking cool' stunts in the past, and generally fails. I do think the GFS is struggling with the pattern, as it often does that far out (and the signal is not very robust anyway with intra-model disagreement)... I'm starting to agree with John H now that the ECM is the model to keep an eye on perhaps, as I'm not having much confidence in the GFS at the moment.

 

Do we think the Scandi trough element is being overplayed a tadge?

Edited by SP1986
Link to post
Share on other sites

Around 52% (27) of the ECM members go with the op run at D5: http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa%21120%21pop%21od%21enfo%21enplot%212014011912%21%21

 

That is, HP over the UK, all the UK with pressure over 1020. Circa 25% of the members have the HP further south (cluster 2); a N/S split. About 23% (cluster 3) have a mixture of various plots. So by D5 ECM has just over 50% support for its op run (that includes the control). This is about twice the support the GEFS have for the ECM outcome.

 

GEM has 33% support amongst its members for its sustained UK HP: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=1&mode=1&ech=180

 

The ECM op remains an outlier for upper temps D9 and D10 for parts of the UK, eg Gloucester 6c higher on the op than the mean at D10.

 

No done deal either way at the moment but the 06z GFS op and Control are both maintaining the Scandi trough though they play around with different evolutions. But by D8 both have the UK influenced fully by the trough, the op sustains this till D15+, whilst the Control has the ridge more towards Iceland and it is less prolonged and influential than the op (W/E divide).

 

Difficult to call just yet though the GFS 06z op has little support so that outcome not likely at the moment: http://modeles.meteociel.fr/modeles/gens/runs/2014060806/graphe4_1000_306_141___Londres.gif

 

 

 

 

 

 

Edited by i'm dreaming of...
  • Like 1
Link to post
Share on other sites

Its difficult to see a prolonged hot spell developing looking at the latest from GEFS

Posted ImagePosted Image

CFS ensembles concur, with west being best / days 5-15. ECM ens also trending cooler into days 10-15

Posted Image

Edited by draztik
  • Like 4
Link to post
Share on other sites

Must admit I can't see a huge difference between the GEFS and ECM except the strength and ridging further east north of the UK of the warm air by the former. (checking the upload)

post-12275-0-50294600-1402236720_thumb.p

post-12275-0-36598300-1402236730_thumb.p

Edited by knocker
Link to post
Share on other sites

Out to day 8 this morning and all models once again agree that pressure will be high over the UK meaning dry and (away from the coasts) probably reasonably sunny weather. Where the models digress significantly is over the Arctic as relatively low heights allow the Euro and GEM to put the high over the UK and draw in warm uppers while the GFS goes for a dry northerly and chilly nights. Worth noting that the ensembles largely back the GFS operational..

 

Posted Image

 

Posted Image

 

 

The major question for for me when and where the high near the UK and the high near Greenland meet up, no real agreement on that and slight adjustments seem to swing output later on from cool to hot and back again. Drier than normal conditions would be the only call I could make at the moment. Temperature wise? Not a clue.

 

Away from the coasts GFS would probably still produce reasonable maxima, it's mainly at night when the cool uppers would come into play.

Link to post
Share on other sites

GEM showing high pressure firmly in charge at t150

 

Posted ImagePosted Image

 

UKMO continues to improve with the low to our east only really affecting parts of Scotland at t120 it looks fresher for Scotland at t144 on UKMO but remaining warm the further south you are

 

Posted ImagePosted Image

 

GFS also shows high pressure over us with temperatures ranging from the high teens to mid 20's though some showers can't be ruled out in places

 

Posted ImagePosted Image

  • Like 4
Link to post
Share on other sites

Once again this evening we have UKMO and ECM in disagreement for the position of the high on Friday

 

Posted ImagePosted Image

 

I'm surprised these two are not in agreement by now maybe they'll get closer tomorrow

 

Beyond that ECM now suggesting the low to our east will move in with it turning fresher in the north

 

Posted ImagePosted Image

Edited by Summer Sun
  • Like 1
Link to post
Share on other sites

The GFS at 12z 500mb anomaly has the cold air from the Arctic to Scandinavia and eastern Europe. The Atlantic dominated by the warm air with the eastern edge of the Azores ridge over the UK.

 

The ECM upper pattern for the weekend broadly similar.

 

Surface wise this leaves the UK under the influence of the high to the west except briefly a trough from the east pokes it’s nose into Scotland on Sunday. Temps around normal but a tad below in n. Scotland.

 

 

post-12275-0-42933500-1402255245_thumb.p

post-12275-0-50226700-1402255252_thumb.p

post-12275-0-45487000-1402255261_thumb.p

post-12275-0-02542600-1402255275_thumb.p

post-12275-0-44661300-1402255282_thumb.p

post-12275-0-05609500-1402255290_thumb.p

post-12275-0-90106400-1402255299_thumb.p

  • Like 1
Link to post
Share on other sites

All 4 ensemble forecast runs from the updated CFS ens showing a negative temp anom into days 5-10 & 10-15 for the UK. Usually we see quite a lot of variation between the models. Tho all singing from the same hymn sheet atm

Posted ImagePosted Image

Edited by draztik
  • Like 3
Link to post
Share on other sites

The outlook looks good up to and including Saturday now, plenty of fine and reasonably warm weather.

The models are again trying to pull a more significant northerly down into week 2, again will it end up like that or will high pressure end up closer to the UK keeping conditions warmer.

 

Could we reach the halfway point of June with temperatures and sunshine amounts above normal? Certainly possible given the output. The Metoffice seem keen on a north/south split developing and continuing through mid-month.

Edited by Captain shortwave
  • Like 1
Link to post
Share on other sites

Yes PM,could be a pattern change on the way as we head towards mid June with pressure falling

to our east and heights to the west/north west and would be quite a cool down over scandi compared to the last few weeks.

 

ECM mean anomalies at day 10.

 

 

Looks like a decent match for the MJO phase 4 composite as well.

 

 

 

  • Like 4
Link to post
Share on other sites

The ECM ens is not a million miles away from the ops. later next week a suggestion that the colder air to the east may not have given up the ghost.

post-12275-0-50152000-1402261191_thumb.p

post-12275-0-48845200-1402261198_thumb.p

post-12275-0-99339800-1402261212_thumb.p

post-12275-0-25812600-1402261222_thumb.p

post-12275-0-82817600-1402261234_thumb.p

Edited by knocker
  • Like 6
Link to post
Share on other sites
 

The outlook looks good up to and including Saturday now, plenty of fine and reasonably warm weather.

The models are again trying to pull a more significant northerly down into week 2, again will it end up like that or will high pressure end up closer to the UK keeping conditions warmer.

 

Could we reach the halfway point of June with temperatures and sunshine amounts above normal? Certainly possible given the output. The Metoffice seem keen on a north/south split developing and continuing through mid-month.

 

Nice to read something a bit more positive for the near term rather than just focusing on the cool pattern showing for a week ahead onwards. 

 

However, unfortunately for some, the GFS 18z does continue a trend for heights to gradually move West into the Atlantic working their way up towards Greenland. This just doesn't do us any favours if it is hot weather you are after...and I can understand the despondency from those that may suffer from potential cool cloudy weather along some coastlines. (If it verifies this way)

 

If the sun comes out, it would at least be pleasant enough getting into the high teens and around 20 degrees in the South. Nights would be cool/chilly though with single figures in some areas. Eastern areas may also see showers, being furthest from the High pressure and with the Low pressure to the NE in Scandi.

 

Not the worst weather outlook compared to other recent Summers and their trains of Lows, but personally I see this as something more akin to mid-Spring rather than Summer.

 

Still...we got this week to get through - let's see what the models look like towards the end of it...

  • Like 4
Link to post
Share on other sites

 

 

 

Nice to read something a bit more positive for the near term rather than just focusing on the cool pattern showing for a week ahead onwards. 

 

However, unfortunately for some, the GFS 18z does continue a trend for heights to gradually move West into the Atlantic working their way up towards Greenland. This just doesn't do us any favours if it is hot weather you are after...and I can understand the despondency from those that may suffer from potential cool cloudy weather along some coastlines. (If it verifies this way)

 

If the sun comes out, it would at least be pleasant enough getting into the high teens and around 20 degrees in the South. Nights would be cool/chilly though with single figures in some areas. Eastern areas may also see showers, being furthest from the High pressure and with the Low pressure to the NE in Scandi.

 

Not the worst weather outlook compared to other recent Summers and their trains of Lows, but personally I see this as something more akin to mid-Spring rather than Summer.

 

Still...we got this week to get through - let's see what the models look like towards the end of it...

 

Indeed, a fair amount of time and considering the uncertainty we have seen recently, I would say that cool weather wasn't a given just yet into week 2.

Given even the worst solutions from the GFS you can still see that even a 100/200 mile shift east and suddenly the surface conditions would be warm and sunny for near enough all. At the range in question that is certainly possible.

This morning the GFS and GEM both pull the high to the west of Ireland

Posted Image

Posted Image

Both similar in developing a second ridge over the Eastern US and into Canada, this teases our ridge further west.

 

UKMO on the other hand has high pressure slap bang over the UK

Posted Image

Eastern areas might be ok in a slack northerly around the high.

 

Looking at the GFS ensembles, there are suggestions that the operationals might be overdoing this evolution and tend to keep high pressure close to the UK.

Posted Image

Posted Image

Not a bad mean to be honest.

 

So not a bad week this week (in fact the GFS has a high of 27C for Friday). Weekend and beyond isn't sorted yet so hopefully we can get a better set up than a long drawn cloudy north easterly. One thing is for sure, it looks mostly dry for many for the foreseeable future once we get the showers out of the way today and tomorrow.

Edited by Captain shortwave
  • Like 2
Link to post
Share on other sites

The GFS thoughts for the upcoming weekend.

 

The 500mb anomaly has the cold pool over the Arctic troughing down to Scandinavia and the cold pool stretching way to the east.  The warm air western Atlantic/Greenland with large ridge NS over the UK to Azores high.

 

Leading to a relatively simple surface analysis.

 

Saturday through Monday an area of high pressure to the W/NW of Ireland 1032mb.  Northerly winds becoming NE by Monday.  Saturday wet over the UK otherwise fairly dry. Temps on Saturday slightly above normal but cooler through the next couple of days and slightly below normal by Monday.

post-12275-0-29450500-1402293732_thumb.p

Edited by knocker
  • Like 2
Link to post
Share on other sites

Still difficult to call on the GEFS for week 2 although a swing in favour of UK HP on the 0z run.

 

D7 mean: post-14819-0-97077700-1402293739_thumb.p  D9 mean: post-14819-0-97471500-1402294016_thumb.p

 

It looks like the placement of the ridge-trough is going to settle very close to the UK, and for instance if we get the Control run we are in for 10 days of settled weather:

 

post-14819-0-25270800-1402293965_thumb.p  post-14819-0-88001800-1402293973_thumb.p

 

Even around D7 there are about four different clusters so the uncertainty remains. This carries over to ECM ENS; their 5 day ensembles had 5 clusters and only 20% support for last night's 12z op: CLUSTERS.

 

GEM has what appears to be the favoured solution of the GEFS up until this morning, an Icelandic ridge at D7:

 

 post-14819-0-91187700-1402294213_thumb.p  With the Scandi trough digging NE to SW through the UK:post-14819-0-36525300-1402294428_thumb.p

 

UKMO sort of closer to this morning GFS mean at D6, with the ridge further east: post-14819-0-28389100-1402294325_thumb.g

 

Hopefully the 0z GEFS suite will trend during the next few runs; London 2m temps: post-14819-0-53446100-1402294560_thumb.g

 

 

 

 

Link to post
Share on other sites
Guest
This topic is now closed to further replies.
×
×
  • Create New...