Model Output Discussion 31/03/14 onwards.

[phil nw.]

But closer to home.. With nearly all Models pointing towards unsettled weather after an initial push of Heights towards the end of the week which will only feed Low Pressure systems diving S/E, It's difficult to give maximum caution,  As this pattern has been the growing trend over the past few days.

Yes Rob have to agree with that and BA and Knockers thoughts.

That Azores ridge for Friday looks like a 2 day only offer before a resurgence in the jet starts to flatten it by early next week.

Those of us further south and east may just squeeze a decent Sunday out of it too but already modeling shows the Atlantic bringing rain into the north west by then.Maybe a little soon for exact timing and details on this but the general trend from the 00z ECM and GFS runs are going with this now.

Week 2 then shows the trough digging se into Europe again dropping a cold upper pool over the near continent again.

Naefs and ECM Ht anomalies for day 10

 

 

back to square 1 as they say-unsettled and rather cool-after a brief respite at the end of the week.

[Summer Sun]

GFS like UKMO looks promising for a settled spell to develop later this week gradually turns more unsettled from the west during Sunday

 

 

After an unsettled spell (though not a complete washout) GFS shows pressure falling over Greenland which in turn allows pressure to rise for the UK

 

Edited May 26, 2014 by Summer Sun

[Alex]

It's been touted a few times on the GFS over the last few days and I would say its time to look to our SW for a pressure rise in early June. The 06z shows some very stable summery conditions in its latter stages. This is definitely in line with a burst of westerlies triggered by a rise in angular momentum.

[summer blizzard]

Well at least I'm not alone. Looking at the ECM ops the upper air is similar to the GFS. I'm still favouring a possible build up of the Azores ridge as the Russin retreats to the east.

 

Surface analysis gives a touch more prominence to the Azores high but the UK still comes under the influence of the northern trough.

 

 

Both GFS and ECMWF continue to show a very unsettled cool/wet turn of Month from the N/W this morning.

 

 

Given the charts above and the trough over Europe i'm pretty sure that the only route out is a complete pattern change. That high to the east is only ever going to try get into the Arctic (backing the current pattern) which means the only route out is a blowtorch (strengthen the thermal gradient over the USA and give the Jet enough strength to back the high east into oblivion) because a stagnant trough is always going to want to join the weaker heights over Europe and probably reinforce a high to the north.

[knocker]

Just had a look at the GFS 06z 200hPa Geo. Ht and wind chart for the 7th June. I know.

 

Very low heights west of Greenland, and over Spain with a ridge running SW/NE west of the UK.

 

Thus the jet, which is quite strong, zips out of the US, tracks around the Greenland low, swings north then west around the ridge and passes north of Scotland. Similar setup until end of run.

 

It's possible under this scenario to get stronger ridging of the 500 hPa anomaly from the SW over the UK but the cold pool would still be around Spain so perhaps one would expect the ridging to be transient. In reality the words "clutch" and "straws" spring to mind.

Edited May 26, 2014 by knocker

[summer blizzard]

I am thinking the same as you knocker to be fair, trouble is will the other models support this or reject it?

 

They've already rejected it i'd say. I expect the 12z GFS to back the unsettled outcome again.

[IDO]

Looks like the 06z was having a bit of fun in FI:

Both op and control showing extreme pressure scenarios compared to the GFS mean (though each has some support).

Funny enough its the Control that brings the more interesting weather:

Both look well outside the mean to be taken seriously...yet.

Edited May 26, 2014 by i'm dreaming of...

[johnholmes]

Think bluearmy its very hard to tell to be honest as the AO and NAO are in actual fact pretty neutral, maybe a bit negative but not by much.Need to look at things with maximum caution at this stage methinks.

 

I think most folk who have watched the models over several years agree that, whilst the AO and NAO cannot be ignored, they have less influence than in the winter. Remember also that both are no more than indications of the predicted differences in surface pressure between north and south.

Edited May 26, 2014 by johnholmes

[Alex]

As always - caution at this stage but the latest GFS output was not a complete outlier with many members showing a warming trend into June. It could well be a little early but I most certainty would punt for a pattern change towards mid June in line with some of the changes upstream.

http://www.wetterzentrale.de/pics/MT8_London_ens.png

[Polar Maritime]

I have just had to delete numerous off topic posts/one liners, As to stop cluttering up the thread so it runs more smoothly please can we only discuss Model Output Discussion only in here. If you are unsure of the rules, Or you know it's off topic then please don't post in here.

 

This warning only apply's to a very small handful of persistent members, For the rest keep up the good work and please continue.

 

Many Thanks

Edited May 26, 2014 by Polar Maritime

[knocker]

I was thinking that some movement of the cold pool west of Greenland might help, certainly could reposition and weaken the jet and perhaps allow some build up of heights in Europe and/or to the SW. Perhaps a glimmer? I know it's way down the line but I'm just having a senior moment. Time for a power nap.

Edited May 26, 2014 by knocker

[knocker]

It's been touted a few times on the GFS over the last few days and I would say its time to look to our SW for a pressure rise in early June. The 06z shows some very stable summery conditions in its latter stages. This is definitely in line with a burst of westerlies triggered by a rise in angular momentum.

 

I'm afraid you will have to explain that to me as angular momentum must remain constant. Conservation of angular momentum. As I understand it to achieve the latter if a mass of air changes it's position on the earth's surface such that its distance from the axis of rotation also changes then it's angle of velocity must change. No doubt I'm being a tad thick.

[Milhouse]

GFS 12z looking rather decent for next weekend. Still cant rule out the risk of a shower but in light winds it should feel pleasant.

 

And heading on into Monday, low pressure being held back to the northwest allowing the fine conditions to persist.

 

[Summer Sun]

UKMO and GFS are both maintaining a settled end to the week this afternoon, can't rule out the odd isolated shower but on the whole a settled end to the week looks likely at this stage

 

GFS keeps the low further west this afternoon so I wouldn't be surprised if the high hangs around longer on this update

 

 

UKMO

 

Edited May 26, 2014 by Summer Sun

[draztik]

big differences between the gfs and gem around day 6

Gem and gfs at t150

[ANYWEATHER]

big differences between the gfs and gem around day 6

Gem and gfs at t150

I think the 12z ecm will be closer to the gem rather than gfs....

[phil nw.]

The GFS at day 6 send more jet energy sliding under the block to the NE which would make for a different outlook in week 2.

UKMO continues with the earlier suggestion of flattening the Azores ridge as does the GEM.

Let's see if the ECM will support the GFS later but at the moment it is on it's own against the other Operationals and the 00z ens means.

[Captain Shortwave]

Certainly hope the GFS is onto something with rebuilding heights over Scandinavia (GFS ens)

With the main upper trough west of the UK, temperatures would be on the up with the most unsettled conditions in the south as precipitation tries to come up fro the continent.

Edited May 26, 2014 by Captain shortwave

[Summer Sun]

ECM continues with this growing trend now to a more settled and warmer end to the week

 

Edited May 26, 2014 by Summer Sun

[Captain Shortwave]

Well the ECM decides to not back any other output

Though given the past week or so, should we really be surprised. ECM throws the low over Eastern Europe back towards us after a reasonably good weekend weather wise. Again I feel that heights are being eroded and removed far too progressively, but on the other hand we simply can't get any settled spell over the UK either

Edited May 26, 2014 by Captain shortwave

[knocker]

Just a quick comparison of the last two GFS anomaly runs for the 7th. Not a huge difference but moved the trough a bit further west and the warm air to the east further east. Of course not reliable.

[SP1986]

Some positives tonight I feel, the GFS not so keen on bringing the low pressure in quite so readily on this run.. it's only one run so we can't say whether it is definitively correct, however it is matching it's ensemble members, which have been quite consistent. 

 

The ECM showing signs on the 12z of a slight gradual change towards the GFS. Perhaps this is going to be a middle of the road episode! Which would be ok!

[Milhouse]

Low pressure forming over Greenland on this run. So while we still have high pressure in the wrong place we dont have low pressures attacking the UK from off the Atlantic. A rather messy sort of pattern is the result with mostly light winds, average temperatures and a scattering of showers likely.

 

[shaky]

Big improvements from all the models with high pressure sticking around for a bit longer than previously shown!!hopefully the models can build on it over the next few days!!

[ANYWEATHER]

Complete contrast between T+168 for gfs and ecm,,,,,,,I think the Money is on Ecm........