Model output discussion - 1st December onwards

[winterof79]

38 minutes ago, ANYWEATHER said:

Evening, It really makes my heart beat faster that people come on here hoping for a White Christmas! How often does that happen? Once in a lifetime? Ecm has dropped its stupid southern European high and gives us the Atlantic, Much better than its previous run. It does look like some folk will see some snow over the Christmas period, upland areas of course favourable, just want the jet stream to dig a little further south and some folks will be happy during Xmas day. Folks the Atlantic is in full control as per normal , So in summary... Wet and Windy , Mild , Sunny , Sunny intervals , cloudy and cold , damp , snow on hills /Mountains ,Stormy, Ice and slush, Drizzle, a few tornadoes,. sunny with blue skies and frost. In reality  the  Atlantic has a lot to offer,

Last year we were 24 hrs from a white Christmas as it snowed heavily on Boxing Day.Happens more than some think if NIMBY ism is taken out of equation

http://e.infogr.am/white_christmas_over_the_years?src=embed

 

Edited December 13, 2015 by winterof79

[seaside 60]

So the models are showing a huge area well above average from USA, Europe and more.

So where is the other side of this ie the well below average regions.

Does anyone not feel that there will be a nature re balance and extreme below temps soon.

[Eskimo]

10 minutes ago, seaside 60 said:

So the models are showing a huge area well above average from USA, Europe and more.

So where is the other side of this ie the well below average regions.

Does anyone not feel that there will be a nature re balance and extreme below temps soon.

Huge area of low pressure above the pole (polar vortex) locks in the cold weather across the high latitudes. The mid-latitudes (Europe and the US) can't tap into any of that cold. Quite normal. 

[Mair Snaw]

5 minutes ago, Greenland1080 said:

18z rolling out...I sense a eureka moment for cold and Xmas

I hope your right Greenland1080 somethings got to give soon surely this cant go on and on and on.... pattern has to break sometime right??

 

[Duane S.]

2 hours ago, JOPRO said:

At what point are we in barttlet set up? 

This gets banded around every year. The vast majority of the time incorrectly, however this is as close to a proper one setting up as I've seen for a while. Hopefully it won't get to that but IMO it has to at least be a possibility this time around.

The mid month window of opportunity for a cold spell is all but a distant memory, we need the minor strat warming due in a few days time to be the start of the fight back against it. Get some wave activity going and stop the raging vortex having it all its own way. There are tentative signs but alas only that right now..

Hopefully we will see more of this in the coming days...

If only for something nice to look at least :-) 

[Stormyking]

As much as the charts are a complete horror show for coldies, and dont get me wrong I would love it to get cold with Snow, frost, ICE etc. Though as true and proper Weather Enthusiast, i'm finding the potential for the December high temperature to be broken is very Interesting.

 

Still time for things to change on the road to Christmas or just after, though not looking very promising, we all know how sudden things can happen at times.

 

Still also have January, February and even March too :D, in the meantime, I find this incredible Mild weather quite interesting

[Nick F]

50 minutes ago, seaside 60 said:

So the models are showing a huge area well above average from USA, Europe and more.

So where is the other side of this ie the well below average regions.

Does anyone not feel that there will be a nature re balance and extreme below temps soon.

Much of Siberia west to NW Russia stays pretty cold. 

A real dearth of positives to conjure some pattern change for the rest of this month, though the ECMWF still driving the MJO wave into phase 7 by Dec 27th, which can trigger tropospheric blocking,

 

... this coherent MJO goes against the general El Niño climo which tends to subdue the MJO into the circle of  death. Though Australian Bureau of Meteorology seems to suggest Nino has reached its peak now with a gradual easing ahead. The are even comments over on the US forums that there has been a pattern over N America more typical of  La Niña (western trough/eastern ridge) rather than El Niño (southern trough/northern ridge) in November and so far this month, so the pattern upstream by no means typical of an El Niño response so far, though this may change.

 

[pyrotech]

The operational is an outlier but that would be very bad news for Cumbria

lets see what the GFS decides, but yes european Ski looks bad before New year and mild and wet most likely for the UK

[knocker]

Going through the motions here but looking at tonight's anomalies no sign in the foreseeable of any change from periods of wet and windy weather, with possibilities of severe gales. The temps should slowly descend from the current above average levels to around normal. The ext out toT360 indicate much of the same.

 

[Ali1977]

Much better angle of jet on the pub run at day 8, should get slightly cooler uppers coming in on day 9/10

infact 850s on day 9 are 10c colder than the 12Z!! And is that some WAA over Canada showing at T222

Edited December 13, 2015 by Ali1977

[Stormyking]

Slight better look on the 18z, looks more like a cold zonal shot for a time, still not looking good though, though I think any coldie would take babysteps for anything remotely cold :L

[Geordiesnow]

Its interesting the last 2 GFS runs want to develop some sort of ridge of high pressure between Scotland and Iceland which may enforce a pattern change sooner than people would expect however the Euro models are having none of that and look a lot more flatter and zonal whereas the GFS may hold a little bit more of an interest. 

Regarding the mild weather, some subtle differences, it looks like the real milder air will arrive a bit earlier along with its rainfall but is forecast to clear on Wednesday  quicker than this mornings model runs have indicated and Thursday mildest day has somewhat gone as the cold front is forecast to head through quicker than previous runs. 

On Friday, the GFS does show something marginally different with what I mentioned in me first paragrapg which whilst on this run does not really affect the overall pattern but may have some sort of influence in future runs if the GFS is on the right track. 

Also I agree with Stormyking comments about that this very mild spell is interesting because the potential is there for the temperature record to be broken(ECM definately shows this potential) so its one too keep an eye on for this week. Also the minimum temperature record could well be broken this week on Wednesday night for sure. 

[Mucka]

8 minutes ago, Ali1977 said:

Much better angle of jet on the pub run at day 8, should get slightly cooler uppers coming in on day 9/10

infact 850s on day 9 are 10c colder than the 12Z!!

 

Yes and perhaps more importantly some amplification behind the trough.

 

Edited December 13, 2015 by Mucka

[nick sussex]

4 minutes ago, Ali1977 said:

Much better angle of jet on the pub run at day 8, should get slightly cooler uppers coming in on day 9/10

Thanks to that ridge extending in towards Svalbard this helps divert some energy se'wards. The fact that the GFS 18hrs is an improvement shows how bad things are for cold!

 

[Ali1977]

Strat is warming , pattern is changing!!! Good pub run...

[Mucka]

Just now, nick sussex said:

Thanks to that ridge extending in towards Svalbard this helps divert some energy se'wards. The fact that the GFS 18hrs is an improvement shows how bad things are for cold!

 

LOL that is very true.

But this has been the first signs of any amplification upstream around day 10 so all we need now is for that to gain in strength and the jet profile out of the states to be more favourable - should be a doddle. 

[Cheshire Freeze]

As some have noted, a better day 10 chart with blocking back over Siberia and better NH profile overall

 

[Cheshire Freeze]

5 minutes ago, Ali1977 said:

Strat is warming , pattern is changing!!! Good pub run...

Warming is more defined as it's trop lead....see Siberian ridge. Always treat these scenarios with caution!

[knocker]

Frankly I would think this the worst of both world's. if of course it came to fruition, with severe gales and not a little rain.

 

[snowray]

Every attempt at a Northwesterly/Northerly, even in deepest FI la la land is scuppered by the almighty Euro high. Its a case of Euro high rules ok!

Can't believe that we cannot even get a half decent toppled by the end of the month. Still some chance for a white Christmas though for high ground in the North, maybe Wales and Ireland too, in the meanwhile blow torch temps for many this coming week particularly Thursday down here, maybe 16/17c where the sun comes out.

Edited December 13, 2015 by snowray

[nick sussex]

Tragic, any amplification sees the Euro high and disappears . Its like this synoptic has now been etched onto Europe for ever more.

At this rate the Euro high will wipe out the ski resorts for the whole festive period, ghastly, awful run.

Overall regardless of some hints at taking the jet a little further south the PV whilst sat to the north will scupper anything wintry.

Whether the MJO which Nick F mentioned earlier can shuffle the NH pattern we'll have to wait and see. The issue really is whether it can survive the El Nino or whether it weakens? Can it get to phase 7?

 

 

[Daniel*]

34 minutes ago, snowray said:

Every attempt at a Northwesterly/Northerly, even in deepest FI la la land is scuppered by the almighty Euro high. Its a case of Euro high rules ok!

Can't believe that we cannot even get a half decent toppled by the end of the month. Still some chance for a white Christmas though for high ground in the North, maybe Wales and Ireland too, in the meanwhile blow torch temps for many this coming week particularly Thursday down here, maybe 16/17c where the sun comes out.

Not that true the euro high does not seem to reside on our shores across the channel it's a different story thus we're open to attack not good for Cumbria giving way to more mobility. 

There are some rather cold N/W flows out at T+210 for instance, the run is quite a lot better compared to the last - its gone from 0/10 to 3/10, although there seems to be little suggesting sustained nationwide cold spell. There are increasing incursion of colder sourced winds enough for low level snow in Scotland. The consensus to me seems for temperatures to go to more average values into the third week perhaps slightly below in the far north not as horrendous as what's going on in mainland Europe and the Scottish hills will do well the best skiing conditions in Western Europe I imagine. Also the run shows a 1040mb block in Kara Sea just off Russian coastline which may have wider implications?

i

 

Edited December 13, 2015 by Daniel*

[BlueHedgehog074]

The models do seem reluctant to run the Polar Express service for the cold and snow weather enthusiasts at the moment with essentially some further unsettled weather at times from the Atlantic. 

The next few days, though, generally showing a bunch of Low Pressure systems digging quite far South within the upper trough in the mid-Atlantic throwing some ridges of High Pressure to the North/North-East of the UK - spells of rain moving up from the South or South-West at times. The worst of the wet weather likely to be towards South-Western or Western UK, although as the Lows out in the Atlantic start breaking through further East to the North-West of the UK, this looks to push the ridging over Northern/North-Eastern UK further East and keep heights over Europe quite strong. And, as such, target the worst of the unsettled conditions towards North-Western parts of the UK (Some people, especially those in flooded areas, could sure do with a break from the wet weather). 

The temperatures looking to also be mild at times, more so, over Southern UK (temperatures getting into double figures at times in the South). Northern parts leaning more towards cooler conditions at times, particularly across Scotland with some chilly nights. Some spots in the North, especially again over Scotland, could see a bit of a frost at times. 

Getting further on into the outlook (towards the end of this week and beyond) and you can see that the models keep the ridging and high heights to our East/South-East into Mainland Europe quite strong. A bit of a naughty High Pressure system it's being for those longing for some much colder weather (I appreciate some places do need to dry out, though). This European ridging helping to prevent Atlantic Lows dropping down into our East and continue to steer them North-Eastwards over Northern UK locking us into a mild (especially for Southern UK), windy, unsettled and, at times, cloudy spell from the South-West (example used from 12Z GFS at 144 hours below)

 

Some of this is thanks to various models wanting to spring areas of the Vortex to our North-West around the Greenland area back into full power bringing an increasingly mobile and Westerly set up over the UK.  Low pressure to North, higher pressure to South. This also promoting more of a flatter pattern over the UK with many models towards 240 hours showing hints of a generally cooler/less mild flow taking over from the West. A possibility that the UK could see a bit of a cool-down with more in the way of cool Polar air from the West getting into the mix at times. Specially for Northern areas where wintry weather could become more and more likely, even if it was just mostly for the hills

(examples from the GFS, ECMWF and GEM below. Some little differences between each model, but do seem to show possibilities of some cooler Westerly flows taking over with the European ridging perhaps becoming more suppressed). 

. 

The 18Z GFS showing a variation of a similar theme in FI:

Nothing admittedly too exciting for all the cold weather fans (better than nothing, though, I guess) and is still far off from anything cold and/or blocked. 

Despite the usual scatter that occurs on these charts beyond a few days or so, the below 12Z GEFS ensemble air temperature ensemble graphs from the London and Aberdeenshire graphs perhaps show enough of a dip to suggest temperatures may cool down closer to average figures towards Christmas. And, in fact, in some parts towards the end of the line graphs, the 12Z GFS operational model (green line) was actually a bit of a mild outlier in parts. 

 

So is possible the GFS may be slightly underestimating the possible (slight) cool down towards Christmas and that should more of a cooler Westerly flow take over, it could be a touch more potent than what the 12Z GFS operational has portrayed. I think you sometimes find in these kind of Westerly set ups where you have very low heights to our North/North-West and High Pressure to our South, it can allow secondary Lows to get into the mix. These Lows of which often running South along the trough low heights to our North/North-West, which can provide surprise snowfalls on there Northern flanks. It is also possible that the models may be ramping up the Vortex towards the end of there runs a little too much and is possible that some of these flat(ish) patterns some of the models are showing may become a little bit more amplified within time. Just like when models can overdo amplification of High Pressure in FI at times. 

And while the ensemble means aren't really the best guide to use beyond a certain number of days, for the sake of it, the 12Z ECMWF mean does show similar scenarios to the GFS, ECMWF and GEM operational models above with low heights to the North of the UK, higher heights and pressure to our South keeping us in a Westerly flow.

It is however best, if possible, to use any available ECMWF ensemble spreads and ensemble graphs to get a better picture of the accuracy of the ensemble mean. Again, the mean does at least show that anything very cold and blocked is unlikely. But despite the good support for this sort of outcome, it's not necessarily completely definite. Was only this morning that the ECMWF operational model was showing a ridge from Canada toppling towards the UK with a brief build of pressure over us towards the end of the run - a lengthy UK anticyclonic spell being something that has been lacking. Would say it's a solution unlikely to occur at present sadly for those needing a break from the disturbed weather with an Atlantic, Westerly, dominated pattern being the more favoured option, currently.   

The 500mb means from the NOAA (both 6 to 10 day and 8 to 14 day) additionally showing quite an Atlantic dominated picture with heights likely to stay strong to our South-East over Europe. The 8 to 14 day chart showing possible hints of the pattern progressing a little bit further East with the lower than average heights over North-Western UK penetrating a touch further East with more of a direct Westerly upper flow over the UK (the 6 to 10 day version, for example, has more of a South-Westerly upper flow over the UK). This of which may allow some cooler polar to get into the mix at times, especially for Northern UK, from the West. 

 

Personally, for now, just can't see anything particularly cold or blocked occurring. While things can still change a few or more so days away, it's looking likely a more Atlantic pattern could take over perhaps with some chiller air getting into the mix at times. This again especially so for the North where some wintry outbreaks via Polar Maritime flows could be a possibility at times. That's probably the best it will get for cold weather prospects in the next week or so. There is always perhaps still the possibility that the models are being a bit flat with the pattern and maybe some of the ridging that gets held out West towards Eastern Canada at times may provide some interests regarding more amplified patterns. Otherwise anything really cold and wintry looking unlikely at the moment with the continuing El-Nino(esque) sort of pattern.

Edited December 13, 2015 by DiagonalRedLine

[bryan629]

Heck of a post DRL.. must have taken you ages to put that together... well done you and thank you 

[snowangel32]

Pub run was much better but still leaves us with the classic North, South split. But jet was much further south a small baby step in right direction. Polar Vortex is going to take some shifting away from its base camp it looks mighty powerful. But we have to remember this was the forecast for a wet, mild December so it's all going to plan so far. Let's hope the experts are right about late January and February.