Model Output Discussion 12hrs. 01/10/13

[Summer Sun]

GFS shows things slowly turning milder in the south as we move through the week

 

 

Almost 20c somewhere in the London area

 

 

So whilst it stays cooler in the north (especially northern Scotland) the south will be turning milder and at times wet this week though in drier spells it should feel quite pleasant give the temperatures

Edited October 13, 2013 by Summer Sun

[Skullzrulerz]

GFS shows things slowly turning milder in the south as we move through the week

 

 

Almost 20c somewhere in the London area

 

 

So whilst it stays cooler in the north (especially northern Scotland) the south will be turning milder and at times wet this week though in drier spells it should feel quite pleasant give the temperatures

LOL Scotland cooler? Judging from it more like colder.

[shaky]

Morning All-Things are certainly NOT the norm at the moment with the hemispheric picture.....The fledgling polar vortex is wedged over to the East of Svalbard- leaving the the upstream westerlies weaker than usual - hence the continued +VE heights over Greenland & residual split flow towards western Greenland-(last year the vortex got stuck over the Canadian Maritimes & pretty much stayed there)Im sure some have noticed over the last few days the models correcting & correcting south- this is because ( as mentioned before ) they will have some sort of background assumption about the general trends of the jet- IE seasonal increase in eastward flow over the atlantic-Take for example the ECM at 168 2 days ago-http://www.meteociel.fr/modeles/ecmwf/archives/2013101100/ECM1-168.GIF?00 look at the jet to the North-http://www.meteociel.fr/modeles/ecmwf/runs/2013101300/ECM1-120.GIF?13-12 Now look its further south-Its easier to see in the 850's168 -http://www.meteociel.fr/modeles/ecmwf/archives/2013101100/ECM0-168.GIF?00 0c along Shetland...http://www.meteociel.fr/modeles/ecmwf/runs/2013101300/ECM0-120.GIF?13-12 0c over England- -6 into ScotlandIf you think North of 60 N is in a funny shape- look where the jet is @ 240 on the ECM-http://www.meteociel.fr/modeles/ecmwf/runs/2013101300/ECH1-240.GIF?13-12Somewhere along the line of spain heading East, where as usually its heading NW towards Iceland- that's a LONG LONG LONG way south.In Summary, Its October, I doubt any of us really hope for bitter cold this time of year including me, however the winter coldies are coming out of hibernation & firing up for November.Also the cold hasn't quite filtered to the whole of the UK- because the summer High over Europe hasn't quite receeded yet ( but it will do)What I would say is whilst we cant guarantee any of this will sustain through into Winter it would seem that something is very usual this year- & if that continues things are exactly how we want it- with all the cold loaded to the ENE & pressure blocking over Greenland ( remember the sausage high)If this continues expect early snowfalls over Scotland in North Easterly flows......SPS the NOAA daily & seasonal composites site is not working now due to the US government which is very frustrating.

i was just going to say steve that the northern hemisphere profile looks brilliant for cold weather lovers!!one thing i have noticed aswell is that over the past few days the models have pushed the colder air ever closer to the uk and there is also more undercutting than previously thought!!one question steve!do you think the models will backtrack to such an extent where they show the cold air tracking straight across the uk?

[SMU]

No i dont think there will be a total reversal, maybe a smidge more south...

A bit more shelflife for the summer euro high to go before its finally surpressed-

S

[MR EXTREMES]

No i dont think there will be a total reversal, maybe a smidge more south...A bit more shelflife for the summer euro high to go before its finally surpressed-S

well said steve excellent though seeing each day on the models the low in the alantic correcting south as I said I think half way situation the gem is the poorest of all models just blasting through into northern Europe this is not realistic and the euro heights are starting to retreat.

overall though I reckon a couple more days and we will see perhaps real signs of something colder and wintry into Scotland slowly building ready for November possibly the end of October and indeed very exciting hemispheric pattern setting up.

[Robbie Garrett]

CFS end of November ala 2010, needs to be watched carefully just in case there is a trend we are missing.  Is it me or does climatology say that if the Polar Vortex forms over mostly Russia, and not near Canada/Greenland that high pressure will build that way, or is that only the recent case?

 

 

Edited October 13, 2013 by Robbie Garrett

[Captain Shortwave]

The war looks set to continue with both northern and euro blocks looking stubborn to budge. This is kind of where you would like the Atlantic to power up as it might flatten the Euro ridge, but conversely the major driver for that would probably be for falling pressure to our north. So a bit of a stalemate at the moment, unfortunately all rain seems to be directed straight at us.

What will the endgame be, will heights over Europe finally flatten or will the polar vortex play a power play and slam into Greenland, going to be crucial as the eventual outcome of November could be very well dependent on how the next couple of weeks pan out.

Edited October 13, 2013 by Captain shortwave

[Frosty.]

LOL Scotland cooler? Judging from it more like colder.

Wow yes it looks cold in scotland   

[smithyweather]

No i dont think there will be a total reversal, maybe a smidge more south...A bit more shelflife for the summer euro high to go before its finally surpressed-S

When do you think that I on the northern end of NI could see my first snow? Do you think those -6c uppers on the 18th could reach me?This is off topic and if the moderators want to move it somewhere else thats fine. Edited October 13, 2013 by smithyweather

[lorenzo]

With the vortex where it is continued interest in the Snow Advance with respect to a Siberian High establishing.

These for days 5 and 10.

 

ECM Mean and Det. different with the heights over Greenland, and reminds us of Chionos all that glitters post a couple of days ago when looking at Anomaly output. Postage stamps worth a check.

 

 

Nice post about the Jet patterns Steve, again also annoyed by the re-analysis suite being busted, a right nuisance..!

[phil nw.]

Yes a good summary by Steve M on the current pattern.The mean trough across the Atlantic has trended further south in the last couple of days allowing the colder air to move closer to Scotland for a while.

Certainly with the jet remaining south in the next week or so then the cold to our north and east will continue to establish along with snow cover.

Unfortunately at this time of year it will produce bands of rain and unsettled conditions with frontal systems crossing the Uk from time to time so essentially we will still see the Atlantic type of weather albiet from a slightly different setup.

The one thing that has caught my eye in later modeling is the tendency to lower the heights more across our side of the Pole with  a deepening and expanding upper Canadian trough.

ECM mean day 8

http://www.meteociel.fr/modeles/ecmwf/runs/2013101300/EDH1-192.GIF?13-12

 

This would continue to feed the Atlantic jet which would prolong the unsettled spell possibly to month end.

[Frosty.]

The Ecm 00z ensemble mean shows cold air pushing south into northern scotland for a while in the week ahead and in fact, scotland looks colder than further south throughout, especially when the wet weather pushes north, I would think there is a risk of wet snow across some of the scottish mountains later in the week as the polar sourced & milder airmasses clash. It's a very interesting run, a mild outlook is in no way certain, at least the further north you are although it does still look like becoming relatively milder across central and especially southern britain by the second half of the week with winds veering sw'ly. more of a colder se'ly for scotland and the far north and isles could be in the colder polar airmass for most of the next 10 days, it's finely balanced in my opinion, one thing is certain..it looks like an unsettled spell for the foreseeable with spells of rain and showers for all.

Edited October 13, 2013 by Frosty.

[Cloud 10]

The Ecm 00z ensemble mean shows cold air pushing south into northern scotland for a while in the week ahead and in fact, scotland looks colder than further south throughout, especially when the wet weather pushes north, I would think there is a risk of wet snow across some of the scottish mountains later in the week as the polar sourced & milder airmasses clash. It's a very interesting run, a mild outlook is in no way certain, at least the further north you are although it does still look like becoming relatively milder across central and especially southern britain by the second half of the week with winds veering sw'ly. more of a colder se'ly for scotland and the far north and isles could be in the colder polar airmass for most of the next 10 days, it's finely balanced in my opinion, one thing is certain..it looks like an unsettled spell for the foreseeable with spells of rain and showers for all.

 

The 06z shows just that,with the frontal zone setting up over northern areas which would give a protracted spell of wet weather which we haven't seen for some time.

 

[Summer Sun]

06z shows a big temperature difference in the UK later in the week with parts of Scotland struggling to get above 3 or 4c whilst in England and Wales we are a lot milder with temperatures close to 20c in places

 

Before that the change starts from mid week with milder air spreading up from the south across most of England, Ireland and Wales with only Scotland staying colder

 

 

Next weekend is when we see a huge difference cold in Scotland mild in England (especially Manchester south), Ireland and Wales the North east of England may be cooler through the weekend depending on how far south the colder air gets

 

 

BBC weather for the week ahead also says it will be turning milder

 

By Thursday the mild air sweeps across all of England, Wales and Ireland with just Northern Scotland stuck under the colder air

 

Edited October 13, 2013 by Summer Sun

[gottolovethisweather]

The Ecm 00z ensemble mean shows cold air pushing south into northern scotland for a while in the week ahead and in fact, scotland looks colder than further south throughout, especially when the wet weather pushes north, I would think there is a risk of wet snow across some of the scottish mountains later in the week as the polar sourced & milder airmasses clash. It's a very interesting run, a mild outlook is in no way certain, at least the further north you are although it does still look like becoming relatively milder across central and especially southern britain by the second half of the week with winds veering sw'ly. more of a colder se'ly for scotland and the far north and isles could be in the colder polar airmass for most of the next 10 days, it's finely balanced in my opinion, one thing is certain..it looks like an unsettled spell for the foreseeable with spells of rain and showers for all.

 

Indeed, as stressed by others previously in this thread, I am finding the emergent short-term NH pattern quite fascinating. In my location and for most of us in the UK, on a local level, the weather on the ground will feel relatively autumnal and perhaps depressingly dreary. However, we should also always look at things, from a global perspective and IMHO (as shown by several of today's posts), there are some most intriguing developments taking shape. Which route these developments take, as we enter the final third of October and progress into the final month of Autumn is an area of focus right now.

Edited October 13, 2013 by gottolovethisweather

[Frosty.]

The Gfs 06z op run shows much milder/warmer air from the azores pushing up across the southern half of the uk from midweek, especially further south where temps could soar into the mid 60's F across southern england. Tuesday looks like being the driest day nationwide with some early fog clearing to bring sunny spells but clouds thickening across the southwest later with patchy rain arriving, through the midweek period, heavy rain and milder air will be pushing from southwest to northeast but the frontal rain looks like grinding to a halt across central scotland and there is even a risk of some wintry ppn for the scottish mountains, the far north could remain dry and a bit colder throughout. Looking further ahead, a much more active atlantic than we have seen so far this autumn with a typically unsettled, occasionally wet and windy spell with depressions chasing each other across the atlantic with gales and severe gales at times, especially across the more exposed northwestern corner of the uk with the airmasses alternating between tropical maritime and returning polar maritime towards the end of october, I will only believe it when I see it because we have had these type of charts in FI before and they always fail to arrive.

Edited October 13, 2013 by Frosty.

[Bobby]

Looking at the GFS ensembles there are only 1 or 2 somewhat settled peturbations out to the end of the runs, the rest are unsettled with a zonal looking trend around day 10. Have noticed a decreasing number of anticyclonic peturbations over the past few days. I would wager anticylonic weather is most likely for the forseeable looking at current indications, not particularly warm nor cold but rather wet and windy especially in the N and W as usual. Standard October fare really.

 

Seems to tie in with the MetO further outlook.

Edited October 13, 2013 by Bobby

[Summer Sun]

Wednesday shows the first signs of this milder air spreading northwards

 

 

By Thursday just about all the UK is under a minimum of +4 uppers

 

 

Less cold air is also moving into parts of Scandinavian

Edited October 13, 2013 by Summer Sun

[Snowman.]

 

 

Higher heights over the pole compared to the 6z, High to the south has spread further north as well.

[Summer Sun]

Colder uppers further north on this run so far

 

 

Compared to the 00z

 

 

A milder run so far this afternoon

 

Edited October 13, 2013 by Summer Sun

[AWD]

Jesus Gav, I had to squint to see the difference in the 0c Isotherm positioning there. Whilst technically you are correct, I think the differences between the 0z and 12z charts you show, show there is minimal to say the least. The GFS, as you know, is a global model, so you will always have slight variations the closer you zoom into a certain geographical area.

Like you say though, less cold air looks favourable to sweep up from the south/south west through this week bringing surface temperatures back up to average, perhaps slightly above in the south at times. All in association with a slow moving trough to our west so whilst the air might measure milder on the thermometer, how mild & pleasent it will feel under various bands of rain and showers, especially in the west, is less certain.

Edited October 13, 2013 by AWD

[Captain Shortwave]

Jesus Gav, I had to squint to see the difference in the 0c Isotherm positioning there. Whilst technically you are correct, I think the differences between the 0z and 12z charts of show there is minimal to say the least. The GFS, as you know, is a global model, so you will always have slight variations the closer you zoom into a certain geographical area.

Like you say though, less cold air looks favourable to sweep up from the south/south west through this week bringing surface temperatures back up to average, perhaps slightly above in the south at times. All in association with a slow moving trough to our west so whilst the air might measure milder on the thermometer, how mild & pleasent it will feel under various bands of rain and showers, especially in the west, is less certain.

To be honest it pretty much sums it up, cold air stuck to the north which never makes any real progress south, meanwhile we have very warm air reaching northern France which doesn't look like crossing the channel. Average to mild and pretty wet as Atlantic energy squeezes through the gap between the high to our north west and the high to our south east.

I don't think the heights over Greenland will diminish as quickly on this run compared to the very progressive 06z run.

Question is, is there any feasible route out of this stalemate, at the moment I've seen nothing really. So whilst the synoptics look quite intriguing, the actual weather patterns look pretty stand Autumn fair with rain at times, especially in the south western half of the UK. Mild for many but cooler air might flirt with the north from time to time as shortwaves eject north east across the country. 

Edited October 13, 2013 by Captain shortwave

[Summer Sun]

Whilst the difference may be difficult to see on the maps you can see it better on the temperature charts take Scotland as an example

 

06z

 

 

12z

 

 

A rise of 10c

 

We also have 20c back on the maps for the London area

Edited October 13, 2013 by Summer Sun

[Skullzrulerz]

 

 

Higher heights over the pole compared to the 6z, High to the south has spread further north as well.

Will that do anything?

[Summer Sun]

Will that do anything?

 

The main thing for now is it will send low pressure systems our way with colder air struggling to get down

 

 

Although still wet at times the 12z is certainly a milder run

 

 

With less cold air shown to sweep across parts of Scandinavian and early snowfall could soon be lost

 

For us its a more Autumnal pattern with deep low pressure systems coming our way bringing with it rain, strong winds and mild ish air though it wouldn't feel so mild under any rain.

Edited October 13, 2013 by Summer Sun