Model Output Discussion 29th December - Into mid-Winter.

[Singularity]

The two lows associated with the trough running up the Eastern Seaboard become separated days 6-7 of the ECM 12z, which is a new development - one of the complications I've been musing about - but with a two-faced impact; the leading low engages with the one ahead of it in the mid-Atlantic sooner and shortens the time window for that one to disrupt against the high in our vicinity, but in being the smaller feature it's not able to do much to change the overall angle of the jet to one that points SW-NE, which means the second low moving into the N. Atlantic follows a more or less W-E path and runs along the base of the mature trough, now positioned just NW of the UK. 

The stage is then set for further disturbances to do the same, but increasingly far south as the lack of stratospheric support for a tight tropospheric vortex over Canada begins to take effect (or so it looks to me at this time). I believe a retention of a more active MJO through phase 3 would help with this process.

 

Shorter-term I notice we've lost just a bit of latitude in the ridge Mon-Tue, not much at all in the grand scheme of things yet enough to allow Atlantic air to some some inroads even before the trough disruption comes into play. This may be related to the behaviour of the very shallow low that drifts across parts of Wales and England this weekend - this being an odd system indeed in that it moves generally W-E in an area with no such upper flow to guide it. The 12z runs take it a bit further east than previous ones which is important because it then drops south toward Europe, and the further west it does so the better for keeping a continental airmass in place across the UK.

[chris55]

We eventually get the high pulling back west, just that its so far north and east it is of little use to our patch, however until we actually settle on a clear trend in the 7-10 day time frame (which we probably wont) im just hoping we can see the westward correction Steve M is always talking about!

 

[chris55]

Plus comparing GFS and ECM both at day 10 just highlights why the ECM is so much more favourable in its general evolution.!

240 GFS

240 ECM

Edited January 20, 2017 by chris55

[Stuie]

11 minutes ago, chris55 said:

Plus comparing GFS and ECM both at day 10 just highlights why the ECM is so much more favourable in its general evolution.!

240 GFS

240 ECM

Bolded a part, more realistic?, more hopeful? Or just wishing this is the direction we could take?

Not meant in any "funny" way Chris.

Edited January 20, 2017 by Stuie W

[numbnutts(uk)]

just can,t belive everyone gets so hung up on one run of charts when they will prob change by tomorrow

Edited January 20, 2017 by numbnutts(uk)

[ANYWEATHER]

We can rest assured that the block to the east of us wont do us any good in terms of deep winter. in the next ten days, yes it will slow the Atlantic down but next week in what ever shape or form as at least some influence from the Atlantic.......  .........But Winter is far from over

[NeilN]

I don't know whether it's me, but it seems the temperatures are being down-graded more - none of this mild stuff seems to be coming over and even we in North Somerset aren't doing too badly lately  

[chris55]

52 minutes ago, Stuie W said:

Bolded a part, more realistic?, more hopeful? Or just wishing this is the direction we could take?

Not meant in any "funny" way Chris.

I meant that it is a more favorable evolution if your looking to eventually back that cold west. No runs showing this but if you compare those two charts I posted GFS simply rides the jet over the top to our north and flattens the pattern, ECM offers an undercut of sorts, but as I said way to far away in terms of distance for us. 

Hopeful/realistic.... at this range neither is applicable.

Though definitely would like to see this kind of direction gather some support  

Edited January 20, 2017 by chris55

[bluearmy]

Spreads on the eps show the trough could still dig to our sw in the short term and in the extended, the upper trough sinks a bit further to our sw so that undercutting the ridging seems even more feasible (not quite as yet  so you would see CAA this far ) and at the very least, runners in the base of the upper trough approaching the south of the uk (as in the 12z op) are likely 

the run ends with upper ridge just east of Iceland and upper trough western med. that's a potentially wintry envelope if the bits in between line up 

Edited January 20, 2017 by bluearmy

[geordiekev]

What can I say,  once again like on Xmas and Boxing Day,  perhaps it's time for a quick, sharp reset as this can help move the Azores high into the Atlantic, in the hope it can rise as it has done for months, but hopefully this time in a more desirable position. 

Yeah lrf models called a blocked first half.  Unfortunately, being an island only 90 miles in width in parts,  it's like a lottery getting the high to rise in the sweet spot but it did rise,  it did block, but a smidgen too Far East.

However, 2016 and 2017 have proven the block is king, I only hope any ssw doesn't miss our small dartboard. 

Hope is the keyword as ever, but still plenty of time to get lucky.

To add a lrf of my own in the theme of recent posts this week without models to back up,  I expect a milder period to show up from about July lasting about 2 weeks. 

[legritter]

evening all ,just hoping that something pops up in future runs perhaps high pressure over nw russia backing west so we can at least get a low tracking to our south .even better a SSW  event would be good especially if the dice falls right ,tonights ECM in its later runs with a bit of a push could produce the goods so hopefully next runs could be interesting ,i,m currently suffering man flu plus chest infection so only popping in this forum now and again ,cant beleive i,m waiting for a possible wintry shower event tomorrow night and early sunday ,if i see a flake i,ll try to take a photo of it ,cheers gang .

[Great Plum]

The 18z gfs gives the south east another week (until next Friday) of air frosts - this would be nearly 2 weeks worth on the trot and it's been a long time since that happened... interesting within the context of a 'mild' winter...

[January Snowstorm]

34 minutes ago, geordiekev said:

What can I say,  once again like on Xmas and Boxing Day,  perhaps it's time for a quick, sharp reset as this can help move the Azores high into the Atlantic, in the hope it can rise as it has done for months, but hopefully this time in a more desirable position. 

 

I think at this stage a lot would like to see a reset to at least some kind of weather. In 40 years of living through winters I never remember such a non descript one...

The charts this evening look as bland as ever and it's now a case of looking towards February 

[blizzard81]

Looks like there are quite a few easterlies on the ecm ensembles for debilt. Surprised nobody else has mentioned this on here tonight. Some very cold runs in that suite. Also worth adding that those that go easterly do so at day 7. We are not talking day 10 plus here. Keep the faith

Edited January 20, 2017 by blizzard81

[damianslaw]

12 minutes ago, Great Plum said:

The 18z gfs gives the south east another week (until next Friday) of air frosts - this would be nearly 2 weeks worth on the trot and it's been a long time since that happened... interesting within the context of a 'mild' winter...

Yes - i've mentioned in the CET thread, how the current mean CET value isn't representative of how things have been in the south east in particular, some places could be seeing 14 days with mins below 0 degrees, not an easy feat.

Back to the models, not much to say, only very subtle changes since yesterday, high pressure holding the atlantic at bay for a good 5-6 days at least over England and Wales with glancing frontal activity hitting the far NW by Tuesday/Wednesday. A chilly settled outlook for most.

Later next week - continued signs the atlantic will muster the high away enough to send fronts across northern and western regions at least, but struggling to make inroads into the SE courtesy of sinking heights taking a long time to move away fro our shores. ECM showing a southerly tracking jet kicking in, which would mean a very short window of mild uppers, and then cold polar maritime air feeding in, accompanied by mid atlantic ridging once again..

Apart from the brief snowy episode last week, and the shortlived wet windy spell over christmas there has been very little to talk about so far this winter, and no sign of anything especially noteworthy or unusual as we end January, but there is always February..

[feb1991blizzard]

The GFS 18z stratospherically has at least moved somewhat away from the 12z solution which did look bleak.

[kumquat]

Interesting to see how the seeds of a cold pool can be homegrown and fed when the warm uppers are cut off even over a land mass as small as ours. (OK it seeds over the southwest Atlantic - then heads towards the Scillies - fascinating energy feedback. Reverse flow jet out of NE France)

 

An unpredictable sine wave pattern setting up exiting NE USA that could see random weather types crop up at short notice.

I'd expect cold developments out of the blue from this over the next 5 days. Of course, it's GFS but it's originating in its back yard.

[Fourty Point Three Degrees]

Its been very HP dominated in Europe the last few weeks and very cold, Does anyone know if what would this mean for us if this very set up was happening in July and not January? Would we be roasting in a heatwave or what?

[feb1991blizzard]

Just now, 40*C said:

Its been very HP dominated in Europe the last few weeks and very cold, Does anyone know if what would this mean for us if this very set up was happening in July and not January? Would we be roasting in a heatwave or what?

They certainly would be, we would be hot now and once the winds veer round even more southerly, we would be seriously hot, and if they were to stay that way for any length of time like some runs over the last few days have been suggesting then we could get seriously hot and even your username might not be as far fetched as it seems right now + one big thundery breakdown when an atlantic upper trough did finally ride in over all the surface heat.

[kumquat]

5 minutes ago, 40*C said:

Its been very HP dominated in Europe the last few weeks and very cold, Does anyone know if what would this mean for us if this very set up was happening in July and not January? Would we be roasting in a heatwave or what?

You can't really equate the two as the energy distributions around the NH between those two times of year are like chalk and cheese.

[geordiekev]

6 minutes ago, 40*C said:

Its been very HP dominated in Europe the last few weeks and very cold, Does anyone know if what would this mean for us if this very set up was happening in July and not January? Would we be roasting in a heatwave or what?

Europe has had low pressure from the polar vortex sinking south of recent whilst we have had the non descript high pressure.  In summer we would be mild/hot. Just our luck, but let's hope 2017 can deliver for all 

[chris55]

2 hours ago, blizzard81 said:

Looks like there are quite a few easterlies on the ecm ensembles for debilt. Surprised nobody else has mentioned this on here tonight. Some very cold runs in that suite. Also worth adding that those that go easterly do so at day 7. We are not talking day 10 plus here. Keep the faith

London ens also showing that scatter around day 7- 10. Some very cold members showing up. Not many and not a trend as such but worth watching, the way ECM op has been toying with trough disruption/undercutting some could be pulling that cold pool west or it could be mearly a re-establishment of the Euro high with cold surface conditions. Either way would be good to see these types of runs increasing in the ens.

[Ali1977]

The runs are very uninspiring this morning, and I think this will be the case for a fair few days. I do believe we are now relying on a SSW if we are to get the chance of a decent/severe cold spell, it's only mid winter so of course we could still get something v cold but the chances are now on the slide with nothing in sight from the models or indeed the METO. All eyes on stray warm up and trop response over the coming weeks.

[KTtom]

Solid agreement for a change by the big 3 for southwesterly winds taking over followed by the Atlantic systems pushing in by next weekend.  Indications from the Met go towards increasing level of confidence that high pressure will dominate again by mid Feb I guess as a result of goings on in the strat. Where this sets up will determine if this winter goes out with a whimper...hopefully for us wanting to see at least 1 potent wintry outbreak it will be an Atlantic high and not a Euro as the continent looks like it may have an early spring.

Edited January 21, 2017 by KTtom

[Matthew.]

Yes I noticed the eradication of the cold pool for Europe by the end of next week. Not a good sign. It's potentially going Nina like for the last week of Jan. An SSW would give the best shot at cold if it happens soon enough but could linger HP to the north for summer patterns if it happens to late I feel.