Model Output Discussion 31/03/14 onwards.

[Captain Shortwave]

Well the GFS/GEM and UKMO hold firm this morning and the ECM backtracks a little

Heights building over the south as opposed to over the whole of the UK. 

[Gibby]

HERE IS THE LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM TODAY THURSDAY 8TH MAY 2014.

 

THE CURRENT GENERAL SITUATION. Troughs of low pressure are crossing East over England and Wales today. Scotland lies under a more showery but light Westerly flow and this will spread to all areas tonight behind a cold front.

 

GFS GFS continues to project unsettled conditions for the next week with the better conditions shown yesterday put back by several more days as another depression and associated front cross the UK later next week with further rain and wind at times. In it's later days the run suggests pressure rises of sorts over the UK though sustained fine weather for any one place is not guaranteed with Low pressure shown to continue to brush close to UK shores at times both towards the North and South.

 

UKMO UKMO is still looking very disturbed through next week with Low pressure continuing to be dominant across the UK with rain or showers at times in a sometimes blustery WSW wind in average temperatures at best.

 

GEM The GEM operational develops better conditions later next weekend as High pressure builds up from the South bringing drier and brighter conditions generally with the centre relaxing across Southern Britain by 8-10 days time bringing drier and much warmer weather for most away from the NW.

 

NAVGEM NAVGEM shows High pressure building North just to the West and SW of the UK in a week or so with the unsettled weather giving way to dry and brighter weather with some sunshine for all by the end of the run but with a chill North breeze possible towards the NE.

 

ECM continues to be the joker of the pack with a much stronger rise of pressure North through the middle of next week pushing the Low that other models show moving East over the UK much further to the NW restricting it's influence to the NW while Southern areas become drier and warmer from Wednesday. However, it is much less marked than yesterday with a SW flow maintained to the NW which extends SE late in it's run on a band of rain and a trough before the end of the run suggests renewed and cooler High pressure pushing in from the West temporarily though pressure on this from the NW looks high again by Day 10.

 

MY THOUGHTS  This morning's output continues to show rising pressure across the UK later next week following another 5-7 days of very unsettled and breezy weather with rain at times and cool conditions. The marked improvements shown by ECM in recent runs is not unexpectedly less pronounced this morning as the High pressure rise from the South becomes stalled from pressure from a SW flow over the NW. However, despite all this there is still enough cross model evidence to suggest something of an improvement towards less Atlantic driven weather as we move through the middle of the month with some dry and bright weather around for many though suggestions of high Summer being likely still look a fair way off this morning.

[IDO]

ECM at T216:   Yesterday's 0z for the same time: 

 

Big differences. Not knocking ECM as this looks a difficult one to call, though their tendency over the last 6 months to run with a pattern on their op for several days when other models are showing Shannon Entropy does surprise me.

 

Interestingly GEM are going with HP over the UK from T174 to T240:  

 

The GEFS are still showing scatter from about the 15th:

 

   

 

The two hi-res runs show the variance:

 

D10 op:   D10 Control:  ECM D10: 

 

Edging closer together but a little way to go yet. 

Edited May 8, 2014 by i'm dreaming of...

[Frosty.]

I like this a lot, the GEFS 00z mean charts blossom into an early taste of summer with much warmer and more settled weather spreading from the south, becoming very warm and sunny towards the end of next week onwards, perhaps locally hot in the south with +10 T850 hPa  encroaching into the south of the uk, there will be even hotter solutions among the 00z perturbations but the mean looks fantastic to me, eventually pressure springs a leak but it stays warm and becomes more humid with an increasing risk of thundery showers, with the PFJ forced way north, these charts are summery...from T+168 / 192 hours..LET THE GOOD TIMES ROLL.

[Summer Sun]

Still big differences between UKMO and ECM for early next week

 

UKMO at t120 at t144

 

 

ECM for the same time

 

 

Up to and including t192 ECM maintains its high pressure though northern Scotland looks prone to unsettled weather

 

 

Its at t216 and t240 its backed away will be interesting to how this sits with the ensemble run later

 

[knocker]

There is still no conformity between the GFS and the ECM for next weekend regarding the upper anomaly and following on from that the surface synopsis. By the end of the week the ECM has high pressure dominating the Atlantic and not over the UK as previously. I don't see the STs being as high as some if the ECM is correct. A big if of course.

 

[Summer Sun]

ECM ensemble showing things becoming more settled during next week with high pressure moving up from the south the ensemble shows the high moving away west at day 10 allowing things to turn slightly more unsettled especially the further north you are

 

[knocker]

Hmm. The jet isn't strong. In fact it wouldn't be reportable.

[Milhouse]

ECM and GFS handling things somewhat differently but both agree on high pressure becoming more of a player in our weather over the next 10 days. UKMO taking sides with the GFS meaning that the likelihood is we will have to wait a while longer than the ECM is suggesting. But the signs are there.

[Man With Beard]

ECM ensemble showing things becoming more settled during next week with high pressure moving up from the south the ensemble shows the high moving away west at day 10 allowing things to turn slightly more unsettled especially the further north you are

 

Hmmm, ECM extremely persistent both in op runs and ens. This level of consistency from ECM usually means it's got a grip on things. I sense the GFS and UKMO will move towards its solution soon.

 

Edit: And there you go, the infamously progressive GFS 06Z makes a big move towards the ECM - compared with its 00Z, the low in the Atlantic is being held 500 miles further back by T132:

 

[Milhouse]

ECM and GFS handling things somewhat differently but both agree on high pressure becoming more of a player in our weather over the next 10 days. UKMO taking sides with the GFS meaning that the likelihood is we will have to wait a while longer than the ECM is suggesting. But the signs are there.

 

Well what do i know. Its all up in the air now. The GFS 6z throws up a magnificent run with things drying out and temperatures rising from midweek. Will the UKMO follow this?

[Milhouse]

Things only get better from the 6z. But in typical Spring fashion it all goes pear shaped in FI.

 

 

 

 

 

Edited May 8, 2014 by Milhouse

[Milhouse]

Definite signs from the ensembles of things warming up.

 

[IDO]

Hmmm, ECM extremely persistent both in op runs and ens. This level of consistency from ECM usually means it's got a grip on things. I sense the GFS and UKMO will move towards its solution soon.

 

Edit: And there you go, the infamously progressive GFS 06Z makes a big move towards the ECM - compared with its 00Z, the low in the Atlantic is being held 500 miles further back by T132:

 

 

 

Not so sure ECM has nailed it. If you looks at the ECM D10 anomaly, comparing the op with the mean:

 

Mean:   Op: 

 

 

 

The op has mid-North Europe under a higher anomaly; the mean a lower anomaly (500mb).

 

This shows up on the De Bilt temps: 

 

This shows the op is on the high side of its ensembles from D7-10 suggesting the op may be over doing the pressure rise & warm uppers (though support from the control). Bearing in mind the op was similar yesterday and has since been downgraded, I would not be surprised if the 12z also downgrades the op run again.

 

The mean keeps the Euro trough from D7-10, though it is a weak affair, indicating pressure build is kept further south and west compared to the op.

 

Even looking at the means (0z), ECM still has the pressure rise further north by T168: 

 

GFS:   ECM:  GEM mean: 

 

GEM mean is closer to GFS mean and GEM's mean or ENS do not support the GEM op run.

 

But this may simply be timing issues, as it does seem likely that all models have support for at least a few days pressure build sometime in week 2.

Edited May 8, 2014 by i'm dreaming of...

[Frank Trough]

Not so sure ECM has nailed it. If you looks at the ECM D10 anomaly, comparing the op with the mean:

 

Mean: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifEDM101-240.gif  Op: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifECM101-240.gif

 

The op has mid-North Europe under a higher anomaly; the mean a lower anomaly (500mb).

 

This shows up on the De Bilt temps: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifeps_pluim_tt_06310 (1).png

 

This shows the op is on the high side of its ensembles from D7-10 suggesting the op may be over doing the pressure rise & warm uppers (though support from the control). Bearing in mind the op was similar yesterday and has since been downgraded, I would not be surprised if the 12z also downgrades the op run again.

 

The mean keeps the Euro trough from D7-10, though it is a weak affair, indicating pressure build is kept further south and west compared to the op.

 

Even looking at the means (0z), ECM still has the pressure rise further north by T168: 

 

GFS: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifgens-21-1-168.png  ECM: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifEDM1-168.gif

 

But this may simply be timing issues, as it does seem likely that both models have support for at least a few days pressure build sometime in week 2.

 

how often does any model "nail" day 10, though?

 

The crucial timeframe is much nearer  with regards to any "better" weather next week. It's all about the position and depth of that next low in the Atlantic to whether we see a ridge pushing up ahead of it. Until that's resolved i can't really see much point looking at day 10 mean charts. 

 

I remain skeptical about any meaningful countrywide height rises until i see the UKMO modelling it inside t+96.  

[knocker]

how often does any model "nail" day 10, though?

 

The crucial timeframe is much nearer  with regards to any "better" weather next week. It's all about the position and depth of that next low in the Atlantic to whether we see a ridge pushing up ahead of it. Until that's resolved i can't really see much point looking at day 10 mean charts. 

 

I remain skeptical about any meaningful countrywide height rises until i see the UKMO modelling it inside t+96.  

 

I think that crucially it's all about nailing where the upper ridge and trough are situated as this will drive the surface evolution. At the moment, as can be seen, the GFS and ECM don't agree which is why the situation is still in a state of flux.

[Man With Beard]

Not so sure ECM has nailed it. If you looks at the ECM D10 anomaly, comparing the op with the mean:

 

Mean: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifEDM101-240.gif  Op: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifECM101-240.gif

 

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifECM100-240 (1).gif http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifEDM100-240.gif

I'm thinking the ECM is looking strong in the D5-D8 range, backing it at D10 I agree would be rather optimistic!

GFS 06Z mean is moving towards ECM as well, I would say.

Of course we've all seen these scenarios shift drastically inside D5, but it's looking better and better at the moment, chances of some warm - very warm weather by next weekend getting above 50% now I think.

[Frank Trough]

just housekeeping still at this stage, but the METO now indicating "midweek" for something better...

 

"From midweek there are signs of a quieter spell of weather becoming established..."

[Summer Sun]

Steady run from GFS so far following on nicely from its 06z update an unsettled start to next week looks almost certain but high pressure starts to move in from the south west during Tuesday

 

 

UKMO has started to move towards the rest though the positioning of the low in the Atlantic is still open to debate with UKMO having it much closer to the UK as a result the high only really builds for the south whereas GFS and ECM keep it a lot further west allowing pressure to rise for just about all

 

 

Still some disagreements this afternoon but its a start with UKMO greatly improved compared to this time yesterday

 

We've gone from this

 

 

To this in 24 hours

 

 

GEM trickling out it too also looks like rising pressure during next week

 

Edited May 8, 2014 by Summer Sun

[Captain Shortwave]

GEM and UKMO seem to be more for a north/south split in terms of conditions as opposed to the full on unsettled conditions of the morning suite. 

GFS on the other hand is going for full blown very warm spell

Edited May 8, 2014 by Captain shortwave

[IDO]

GEM similar to UKMO at around D6: 

 

GFS Scandi High:  retrogressing to Greenland: 

 

 

Edited May 8, 2014 by i'm dreaming of...

[Summer Sun]

You have to laugh at times with GFS look at the differences in just 24 hrs

 

 

From one extreme to another in a matter of hours

 

After a settled spell GEM has the low to the north of the UK pushing south

 

 

On the other hand GFS at day 10 is completely different

 

 

Still lots to be resolved but a change to something more settled next week appears to be gaining some momentum this afternoon

Edited May 8, 2014 by Summer Sun

[049balt]

http://wxmaps.org/pix/prec4.html

 

Very dry outlook from week two.

[joggs]

Watch the ecm trend the other way now

[Captain Shortwave]

Certainly a big change with the GFS today, suddenly the end of the week looks very good.

 

GEM and ECM ens from this morning hold heights a bit further south. Interestingly all models want to retrogress the high later on in week 2, though we need to get the high in first before debating that.