Model Output Discussion - The Start Of Winter

[Frosty.]

There is plenty of cold interest on the Gfs 06z operational run with frequent pm incursions and limited mild intrusion, the most potent cold tends to sweep across Scotland but colder air does dig further SE at times. If this run verifies, the risk of snow, frost and ice will continue, especially further north and more widely during Christmas and I can see the gfs is tinkering with a much colder pattern by the end of the run, all that bottled up Arctic air could be uncorked soon.

Edited December 13, 2014 by Frosty.

[Buxton Codge]

There is plenty of cold interest on the Gfs 06z operational run with frequent pm incursions and limited mild intrusion, the most potent cold tends to sweep across Scotland but colder air does dig further SE at times. If this run verifies, the risk of snow, frost and ice will continue, especially further north and more widely during Christmas and I can see the gfs is tinkering with a much colder pattern by the end of the run, all that bottled up Arctic air could be uncorked soon.

 

Complete opposite of what the models actually show!

[Ali1977]

Let's home the 12z GFS's and the ECM flip today and start showing some FI candy....then maybe Ian F will have more positive news from the professionals.

[EML Network]

Some mouth watering charts on offer deep into FI on the 06z 

 

A greeny High seems to be the favorite option on the table. 

 

It's a case of take your pick, far too many showing something similar for it to be a one off, I feel this is the start of something exciting ust in time for the end of the year, as per Met Office 15-30 hints. 

 

Control run last frame 

Run 1

Run 2

Run 4

Look at run 7 !! 

Run 8

Run 15

Run 16

 

PLENTY more runs showing a Greeny high in FI, but that's the pick of the bunch for me, if it's trends your looking for then today has given us  the best charts of the season so far all be it in FI and completely out of the blue too. 

 

Hope to see some firming up on this as we go into the next week ??

[Potent Gust]

Again I have to say I think the Met Office have been pretty spot on so far this winter. The updates that Ian gives us are invaluable. He stated well over a week ago that the Met were pretty sure that the NW/W flow would continue but it would slowly become milder with the winds veering more W/SW. From looking at the model output as it stands at the moment that certainly appears to be the case. At least we have some PM shots to look forward to. I know some people are downbeat but the winter so far has been much more interesting than last years already. I personally have experienced 7 frosts already! Virtually as many as the whole of last winter!

 

Anyway I am hoping the MET are onto something with the potential pattern change later in the month. I will be watching the Met Office and Ian's updates with keen interest. Thanks once again Ian

[bluearmy]

Let's home the 12z GFS's and the ECM flip today and start showing some FI candy....then maybe Ian F will have more positive news from the professionals.

No eye candy likely for another few days yet on ECM op. maybe a bit more amplification end this week but that's it. I think Monday's 12z at the earliest and at the moment, ECM suite seems a bit slower than ncep so perhaps wed/Thursday.

[Frosty.]

I think the general rule of thumb is the further north you are, the colder it looks for most of the time with hardly any noteworthy mild air whereas southern england looks mildish at times, especially midweek but the northern half of scotland in particular looks decidedly wintry at times with frequent shots of pm / arctic air and snow showers.

Edited December 13, 2014 by Frosty.

[Snowman.]

Anoms

 

T240

 

 

T384

 

 

Mean

 

T240 - Possible above average temps in the south.

 

 

T384 

 

 

Turning unsettled further south as troughs make further inroads into Europe. 

[BM4PM]

Hello don't normaly post on here but wanted to ask a question.it seems to me that the 6z and 18z charts seem to favour cold solutions more than 0z and 12z.is there a reason for this?. Cheers

[Jason M]

Looking through GEFS they build further in the last couple of sets towards pattern change. I'm wondering though if we might initially end up with a west based -NAO.

We are at least back in the game though during the Christmas and new year periods.

[J10]

Latest snow blog now out. showing an analysis of GFS for the coming week.

 

https://forum.netweather.tv/blog/189/entry-4854-alps-weather-forecast-13-december-2014/

[MattH]

Just a quick one but the 00z EC ens do pick up on the evolution as per the 06z GFS for example with a trough - ridge - trough pattern, starting over the E USA (trough) into the N Atlantic (ridge) and then down over the UK or NW Europe (trough) in general.

This is within the final block of the ENS between 264hr and 360hr of which there are 3 clusters and these are split 24, 16 and 11. The 24 and 16 members are still far more mobile with temp NW'lies at best through Xmas but the 11 are the blocked regime (and thus produce a cold christmas) so for now at least the most unlikely outcome.

Whilst the general evolution within the EC ENS has been consistent of late they have produced some wild solutions too. I'm a fan of cold weather just as much as the next person and with regards Christmas I think this is the potential saving grace *IF* it comes off. The thought of a mild mT SW'ly at Christmas, as per every year, fills me with dread and disappointment.

So in summary if you're looking at Christmas and the final week of the year (or so) then it's mid atlantic ridging that needs to be watched for as per the 06z GFS, some of its ensemble members and as per 11 of the 51 EC ENS members. An outlier solution for now, but you just never know this could be a weak signal that develops and it'll develop quite quickly no doubt if it's going to happen in the coming days.

Regards. Matt

[Banbury]

Presumably you mean for for potential afterwards, because to my untrained eye it looks like a SW flow with rather mild temperatures

5c , 7c , 5c , 5c , 11c , 12c , 9c , 5c , 5c , 11c , 11c , 6c , 6c , 3c , 3c , 10c

Quite a mixed bag I'd say with no weather on top mild or cold.

Edited December 13, 2014 by ajpoolshark
edited out comment that could be misconstrued as sarcastic

[Frosty.]

There is growing support for a more prolonged cold spell by the new year and it's also pretty clear from the models that the weather pattern is going to stay broadly similar to now for at least the next two weeks with cold incursions from the west and north west bringing wintry showers and night frosts but with less cold / milder wet & windy spells, any settled weather looks very brief..the carrot is being dangled for a more widespread wintry pattern during January 2015..hope it happens :-)

[Barry12]

Afternoon all,

 

while everyone is looking at the potential end of December pattern change, I thought I'd take a look at the end of the week into the weekend. During Friday evening we get another cold PM airflow, with the cold air moving south into the UK. Initially, this will only effect the Northern half of the UK. But, snow will again be a possibility for some, especially over higher ground after a temporary mild spell.

 

 

 

As we move into Saturday temperatures start to struggle, snow would be possible at lower levels, especially for the Northern half of the UK.

 

 

 

Sunday would be the day that things start to get really interesting though, with snow possible to lower levels in the south. We may not have to wait until the end of December to see widespread UK snow.

 

 

Yes, this is at day 7-9, but it is interesting to look at seen as though next weekend could be the time the snow wait is over, and would pretty great to consider it was before any possible pattern change.

[bobbydog]

Accuweather are expecting the Eastern States to go into the Freezer by end of this month which will fire up the jet across the Atlantic. Early days, but I would expect January to be a stormy one across Northern Europe similar to January 2014

in your expert opinion?

cohens forecast states that they expect wave breaking activity to increase by the end of the month leading to an SSW. this would (should) in turn lead to high level blocking and colder outbreaks in eastern USA. and europe. Considering that the models (such as Glosea and not just the ones we can see) are hinting at signs of a pattern change at the very end of their range, this would tie in with cohens forecast. too many people expect that a high SAI and a negative OPI mean 3 months of snow for the UK and are disappointed when it doesnt arrive. however if we read the information provided by the experts who are involved in this research, they actually state that the likely timescales for the effects (proper winter weather) to emerge are into january and even february. in this case, signals are emerging that the earlier option is more likely. by months end we could be looking at some juicy cold charts within the "reliable" and possibly even some actual proper cold weather

[Frosty.]

I'm very optimistic that parts of the UK will have a white Christmas due to the topsy turvy pattern of mild alternating with cold day to day, it should be mentioned that milder air looks like having more success next week, especially through the midweek period but overall it's rather chilly with wintry ppn in the north and occasionally across the south too. At least we are in with a shout for Xmas day to be white instead of the usual green but we require a bit of luck with timings.

[Panayiotis]

GFS 12z clearing some of the PV from Greenland at 144hrs which should allow the Azores to ridge up a bit further in this run, giving us a colder NW...

[Winter Cold]

Yes, its younger brother P also very similar at the same time. Its good to see the Azores high kept further at bay tonight from GFS's

 

[Mucka]

All this mornings talk of mild and no sign of pattern change has me scratching my head a little even though the 00z runs weren't that appealing.

 

We currently have the output moving toward another chilly W/NW outbreak in 5 or 6 days time and it won't be mild out to then either with temps lifting from a little below average to around average generally before falling a little below again.

That takes us out to about day 8 where temps will recover to around average again and thereafter there is some uncertainty whether the Azores high will exert enough influence to bring in a drier milder regime for a while or we keep the same pattern that has been bringing us these brief warm sectors between colder PM flow. (But remember the AH has been repeatedly modeled to play spoiler yet as we come into the more reliable modeling time-frame the troughs have always been backed West and deeper and the AH displaced keeping a more amplified pattern)

 

The last week of December there is a signal for a pattern change with significant height rises in our sector. 

We cannot know if this will develop or how it will develop in line with Ian's thoughts but the signal is there and it favours an Atlantic ridge which would bring a higher probability of colder weather affecting the UK.

Edited December 13, 2014 by Mucka

[winterof79]

Not a bad 144z from UKMO shame the 850 chart is not available

http://www.meteociel.fr/ukmo/runs/2014121312/UN144-21.GIF?13-17

[Barry12]

Last winter we would see cold charts pushed back continuously, this winter it seems the opposite with any mild weather pushed back well into FI. Apart from some slightly above average temperatures it remains below average throughout the reliable, looks like December will finish below average, while not massively so it is 1-0 to the OPI right now in my opinion, as most seasonal models predicted a mild December. If they were wrong about December, surely they can be wrong about the winter as a whole?

[TEITS]

As many know I am a cold ramper but lets be honest some of the comments with regards to the output are way off!!

 

Comments such as "mild weather pushed back into F.I" are wrong. For example the GFS is predicting max temps of 12C next Wednesday.

 

http://www.wetterzentrale.de/pics/Rtavn9617.gif

 

A more realistic assesment of the output is this. Turning milder next week especially midweek before turning colder again next weekend. Thereafter becoming mild again around Xmas before possibly turning colder again after Xmas especially in the N. At this stage no notable cold spell is likely and any snowfall more likely for the higher ground during the colder snaps with the driest weather in the S.

[bluearmy]

low res on the parallel would be more than interesting if it didnt make such a complicated mess of the atlantic troughing.   shame - could have been some eye candy.

[Ali1977]

GFS P FI (360) looks good with heights pushing north and into Greenland, this is what we need to be seeing. This mornings GEFS showing more on this, 12z GEFS may follow.