Model Output Discussion 31/05/14 onwards.

[Weather Boy]

You hardly ever see those sort of charts come to fruition in Winter let alone in Summer.

 

This morning is all change again anyway.

 

 

Classic "return of the westerlies" chart I would say. Decent weather holding on to the south, especially SW, whilst Scotland and N Engalnd and NI have rain bands and showers to contend with, with a fresh breeze.  Whether the Azores high would nose in from there is open to conjecture, but then the premise of that conjecture (ie the model prediction) is educated conjecture anyway!

 

It doesn't surprise me that the models would toy with such a scenario which is hinted at in the Meto long range, but that doesn't make it right and at this range it is highly likely to be wrong, especially as it's the GFS which is poor in low res.

[knocker]

Now looking at ECM ops for Glastonbury. Grim.

 

The 500mb anomaly completely loses the ridge to the west and has the cold Scandinavian air stretching to Greenland and influencing most of the UK under an unstable westerly flow with the cold pool still west of Spain.

 

Not good news for the surface analysis. Thursday not too bad with a shallow low west of Ireland and dry in the UK. But by Friday the low has developed and is 992mb over northern Scotland giving a strong NW in southern parts with frontal activity, Saturday the low 988mb is west of Norway and the AZ high is centred west of Spain pushing NE. This leaves the UK in a strong NW with again fronts affecting the south. Still there so much fluidity in the set up at the moment I'm sure this will change, probably by this PM.

Edited June 18, 2014 by knocker

[Summer Sun]

UKMO remains settled this morning with variable cloud and pleasant temperatures

 

 

The deep low for the time of year over the Glastonbury weekend doesn't have ensemble support from ECM thankfully

 

Op

 

 

ens

 

 

Edited June 18, 2014 by Summer Sun

[Man With Beard]

As many in here thought would happen ... the latest attempt at bringing in a Scandi trough looks set to be another fail, with dry, settled weather continuing into next week:

[knocker]

As SS rightly says the ECM ens isn't as bullish as the ops. The upper air still has a weak ridge just to the west of the UK and the cold Scandinavian air further east The result it doesn't develop the low. Although I'm not sure I'd have too much confidence in this either.

Edited June 18, 2014 by knocker

[SteveB]

Classic "return of the westerlies" chart I would say. Decent weather holding on to the south, especially SW, whilst Scotland and N Engalnd and NI have rain bands and showers to contend with, with a fresh breeze.  Whether the Azores high would nose in from there is open to conjecture, but then the premise of that conjecture (ie the model prediction) is educated conjecture anyway!

 

It doesn't surprise me that the models would toy with such a scenario which is hinted at in the Meto long range, but that doesn't make it right and at this range it is highly likely to be wrong, especially as it's the GFS which is poor in low res.

 

Plenty of fine settled warm weather away from Northern Scotland & East coast of England to enjoy before then.

 

 

 

Edited June 18, 2014 by SteveB

[SP1986]

The 06z demonstrates that the GFS (and possibly models in general) are really struggling with the generally pattern within 3 days from now, which is quite amazing really. The 06z shoves things back west again for the weekend, allowing a slack northerly influence to return, compared to the few previous runs that were suggesting more of an influence from the Azores ridge. Interesting the models cannot get a grip on the pattern, at a time, when this pattern would normally be set and nailed at this point.

Edited June 18, 2014 by SP1986

[summer blizzard]

No real consensus this morning. GFS and GEM do their best to hang onto the high, Euro goes for Autumn.

 

[knocker]

Re, Glastonbury GFS 06z. All change.

 

Dropping the low west of Ireland and for the Thursday, Friday Saturday has HP SW of Ireland giving a dry, tranquil three days. The only wet area is Scotland as a low skirts around north of there.

[SteveB]

GFS 6z has the UK placed on the edge of the UK High northerly battle with neither winning out.

 

The further south you are the warmer the conditions, below is an example of what you could expect over the next few day's

 

 

Edited June 18, 2014 by SteveB

[Bobby]

Noticed Meteociel have the new FIM model now which is expected to replace the GFS

 

http://www.meteociel.fr/modeles/fime_cartes.php

 

These charts present the data model American FIM (Flow-following finite-volume Icosahedral Model), which is probably the successor of GFS. The runs of 0z and 12z go to 240h. The maps are updated from 7am to run for 19h 00Z and 12Z of the run, they have a resolution of 0.5 °. Warning: updates the runs are long enough as it is experimental model

[bluearmy]

Noticed Meteociel have the new FIM model now which is expected to replace the GFS

 

http://www.meteociel.fr/modeles/fime_cartes.php

 

These charts present the data model American FIM (Flow-following finite-volume Icosahedral Model), which is probably the successor of GFS. The runs of 0z and 12z go to 240h. The maps are updated from 7am to run for 19h 00Z and 12Z of the run, they have a resolution of 0.5 °. Warning: updates the runs are long enough as it is experimental model

 

 

not as far as i know it isnt. its an experimental product and unless it gives better results than the upgraded gfs later this year, i think it is unlikely to survive, PRHW14 is the upgraded GFS model due to go live in the autumn (running in paralell at the moment).  no idea where the charts can be viewed.

[mushymanrob]

oh dear

 

 

just what we didnt want to see.... total disagreement.just as we are approaching the pivotal part of summer, the outlook has two distinct but different options. ok, i guess the truth will lie somewhere in between... whilst the gfs gives hope of dry warm sunny weather, the ecm goes for a more mobile, unsettled westerly. if that establishes i wouldnt place much hope on anything sustained and settled for july, the hight of summer.the ops however appear to me to paint a rather 'normal' picture, not too wet, but no lasting heatwave, looking to me like summer 14 will be remembered for being more average then one given to extreme rain or heat.

[Gael_Force]

not as far as i know it isnt. its an experimental product and unless it gives better results than the upgraded gfs later this year, i think it is unlikely to survive, PRHW14 is the upgraded GFS model due to go live in the autumn (running in paralell at the moment).  no idea where the charts can be viewed.

 

More details here -

http://www.emc.ncep.noaa.gov/gmb/wd20rt/vsdb/prhw14/index.html

http://webcache.googleusercontent.com/search?q=cache:C9oec36sFlEJ:ftp.emc.ncep.noaa.gov/exper/nova/CCS-science-Qtrly/7-Derber-GFS.pptx+&cd=1&hl=en&ct=clnk&gl=uk

 

Score card screen shot.

 

 

and here

[johnholmes]

oh dear

 

test8.gif

 

just what we didnt want to see.... total disagreement.

just as we are approaching the pivotal part of summer, the outlook has two distinct but different options. ok, i guess the truth will lie somewhere in between... whilst the gfs gives hope of dry warm sunny weather, the ecm goes for a more mobile, unsettled westerly. if that establishes i wouldnt place much hope on anything sustained and settled for july, the hight of summer.

the ops however appear to me to paint a rather 'normal' picture, not too wet, but no lasting heatwave, looking to me like summer 14 will be remembered for being more average then one given to extreme rain or heat.

 

 

come on mushy, stop being a pessimist, sure if it is correct, ECM, then about 10 days does not look very summery but to suggest it covers the whole of July is a step too far in my view. No please don't tell me if it happens it sets things up, nowt of the sort. It does not look good for the time scale. Go back and look at the issues over the past week to see that. Good guidance for the period it is for-not a lot more, and not even that, as you rightly point out, with no agreement between the two, take a look at the NOAA outputs r my burblings most days.

Edited June 18, 2014 by johnholmes

[mushymanrob]

come on mushy, stop being a pessimist, sure if it is correct, ECM, then about 10 days does not look very summery but to suggest it covers the whole of July is a step too far in my view. No please don't tell me if it happens it sets things up, nowt of the sort. It does not look good for the time scale. Go back and look at the issues over the past week to see that. Good guidance for the period it is for-not a lot more, and not even that, as you rightly point out, with no agreement between the two, take a look at the NOAA outputs r my burblings most days.

 

pessimist or optimist john?... if the gfs version varifies it will be very pleasant.

i dunno john, in the years that we have had a 'good' july/summer it has more often then not shown its hand by the first week in july. i cannot recall a long hot summer starting in the second half of july when the preceeding weeks have been nothing but normal. now id suggest that so far this summer has been 'normal', theres certainly been no widespread long hot spell. so for those of us looking for one, i would certainly bet against one IF theres nothing showing by week 2 of july.

now if you or anyone can correct this notion of mine, please do!

as for the ecm varifying, who would bet against a freshly invigoured jet stream  not sticking around for a while. as i see it, once its established as the ecm anomaly suggests it might, its unlikely to be a short lived affair.

 

itll be interesting to see what todays noaa charts reveal.... as i said earlier i expect what we actually get will be something between the two 'extremes' i posted earlier.

[Gael_Force]

If you want pessimism, Chinese monthly ensemble for July is the place to look. Thankfully, it has been wayward in its predictions recently and the overall pattern of surface temperature anomalies looks very odd - such a hemispheric difference between warm and cold.

[Summer Sun]

Looking more and more likely now that this high will continue into at least the first half of next week

 

 

 

Cloud could be a problem at times but in any sunshine it will be feeling warm

Edited June 18, 2014 by Summer Sun

[Captain Shortwave]

pessimist or optimist john?... if the gfs version varifies it will be very pleasant.

i dunno john, in the years that we have had a 'good' july/summer it has more often then not shown its hand by the first week in july. i cannot recall a long hot summer starting in the second half of july when the preceeding weeks have been nothing but normal. now id suggest that so far this summer has been 'normal', theres certainly been no widespread long hot spell. so for those of us looking for one, i would certainly bet against one IF theres nothing showing by week 2 of july.

now if you or anyone can correct this notion of mine, please do!

as for the ecm varifying, who would bet against a freshly invigoured jet stream  not sticking around for a while. as i see it, once its established as the ecm anomaly suggests it might, its unlikely to be a short lived affair.

 

itll be interesting to see what todays noaa charts reveal.... as i said earlier i expect what we actually get will be something between the two 'extremes' i posted earlier.

I will say that the ECM might look bad, but again it could be picking up a signal and over-doing it. The models have been doing this a lot recently in regards to the significance of Scandi troughing.

Anyway this mornings ECM was backed up by the UKMO at days 5/6, luckily the UKMO is a lot better this afternoon and builds heights nicely into the UK by Monday.

 

GFS looks decent too

 

The one thing an increasing Atlantic jet could do is finally push the high anomaly over or even to the east of the UK and banish that Scandi trough which has brought some pretty disappointing conditions for some. An Atlantic trough would be very useful to force a warmer and brighter pattern.

Edited June 18, 2014 by Captain shortwave

[mushymanrob]

I will say that the ECM might look bad, but again it could be picking up a signal and over-doing it. The models have been doing this a lot recently in regards to the significance of Scandi troughing.

 

i absolutely accept this and i hope the ecm anomaly is wrong. i did say that we will probably get something between the two (i just dont want to be seen as only pessimistic, thats only one option).

[bluearmy]

this is one of those days when that chart mushy posted is  poor for any guidance. ecm op is 'off on one' in fi and as such its 6/10 day mean representation of the op is also going to be odd.

howeverr, it should be noted that the anomolys through week 2 are very weak and as such, anything is possible.

[Milhouse]

Remaining mostly dry and pleasant for another week if the GFS is correct. Lots of dry weather around and temperatures fluctuating between average and above average. The warmth really building next week as the Azores high pushes in.

 

 

 

[Tamara]

The ECM operational as it stood this morning looks unlikely within 10 days - at least for the time being. The ensembles show it clearly amongst the highest level members for windspeed which suggests it is probably premature in its latter stages with the the way it deepens the phasing of the troughing from the atlantic into the Scandinavian trough as the jet stream flattens out to the north.

 

http://www.weathercast.co.uk/meteo/eps/ensemble-ff-london.gif

 

However, in terms of general outlook it is one scenario being played out as events change over the other side of the NH in the Pacific

 

Much as suggested the other day, the modelled High pressure has favoured giving the most summery weather conditions to the west and north west and the coolest and more cloudy conditions to the east and south east as clockwise winds around the perimiter of the High pressure carry North Sea influences to these parts.

 

Whilst the east of UK has stayed on the eastern periphery of the High, the influence of the Scandinavian trough as mentioned above has continued, thus far, to be overstated in the models, and this state of affairs continues to look good value into the medium term as atlantic influences begin to push any attempted cold air advection around the trough to the NE further  eastwards for the time being.

 

As already stated by some, a flatter westerly pattern often asserts itself as we head into the main centre piece period of the summer and can form a crossroads for the fortunes of the remainder of the season. We are starting to see the suggested change as muted in Fridays post towards a shift of fortunes to bring the generally warmer conditions further south, whilst the north becomes cooler and, very gradually, less settled. The current advertising of the High pressure to the west of the UK to send a toppling ridge across the south of the UK, whilst the jetstream sends frontal incursions into more north western regions looks good value at the moment with support from most of the major model ensembles and also as indicated from GEM and GFS operational output

 

That NW/SE eventual split is gaining increased confidence as a destination arrival point. Timing still uncertain however - but most likely the following weekend/ into week 2 and towards the end of June.

 

We are seeing the beginning of the process of energy transport from the western Pacific across to the states as jet stream patterns change there. The PNA has good forecasted support to flip + through the second half of June.

 

 

 

This is just a forecast as reflected by the models and these forecasts, like many forecasts, don't always verify as suggested. However this one we might have a little faith in as perhaps the +PNA signal linking to the emerging el Nino pattern in the Pacific. There is a known relationship and association between a +PNA pattern in the Pacific and El Nino oceanic warming, even though PNA movements obviously do have intra seasonal variability independant of such factors

 

The change in the Pacific jet stream pattern as indicated suggests an eastward shift in a stronger jet stream from Asia across the Pacific towards the US Pacific coast with lower pressure over the Aleutians coast and also over the SE states. The net result of the height field pattern in a positive +PNA phase is that it forces relatively colder air residing in arctic Canada to be pushed southeastward down the eastern side of the US and this will increase the jet stream energy in the atlantic, even in the summer months. Naturally such eastward pressure changes will feed downstream and it is no surprise therefore that the atlantic pattern is predicted to flatten in the way as advertised by the models and so our east atlantic High that has been close to NW UK is set to be pushed south.

 

 On our side of the NH support continues for the presence of High pressure in the eastern atlantic but could any renewed amplification of the jet stream after initial energy transport thereafter lead to reinforcement of the Scandinavian trough to dig further eastward on a more successful basis next time around? Its the scenariothat maybe the last ECM operational picked up on (somewhat prematurely in terms of the more likely evolution) and which leads eventually to more widespreadly unsettled conditions.

 

The composite +PNA pattern does show the general NH overview reflected in the varying scenarios the models are playing around with - a pronounced trough over Scandinavia as well as the eastern atlantic High. However, the presence of low heights over the eastern US at face value decreases the chances of eastern atlantic High pressure backing westwards as modelled so frequently recently and that in turn might restrict the influence of the Scandi trough to the greater part of the UK.

 

 

As suggested the other day, the longer term outlook depends on exactly how and when the atmosphere responds to any associated forcing in tandem with the warmer water Pacific oceanic signal and that remains uncertain for the time being.

 

Edit: The updated ECM operational is again very progressive with the renewed jet stream energy, as described above, and pushes this south very quickly. Another look required to see how it sits in the ensembles - but it remains, at least at this time, as going against 10 to 15 day guidance. The weather becoming more unsettled in the NW with time looks correct, but the speed and extent of the changes are questionable at this stage

Edited June 18, 2014 by Tamara תָּמָר

[SteveB]

GFS 12z shows a continuation of the dry warm theme well into next week and it's only in low res things turn unsettled and cooler.

 

In the meantime warm and dry apart from some fronts affecting the North of Scotland as they drift

around the high.

 

 

 

 

 

[knocker]

The GFS still plugging the change for Glastonbury.

Edited June 18, 2014 by knocker