Model output discussion - 7th January onwards

[Radiating Dendrite]

3 minutes ago, Ali1977 said:

This is a pretty cold chart for 192 from the ECM, but it looks so complicated and full of variables I imagine FI is nearer 144. I think it’s take another 24/36 hours to have a better idea on what is going to happen next Thurs/Fri. 

Yes, think we will need the weekend runs to get a firmer handle on things. 

[Cheshire Freeze]

1 minute ago, bluearmy said:

ECm mobile again ..... was hoping yesterday’s op symptomatic of the higher res picking up a slowing flow but clearly not 

back to expected transition although that day 9 could easily disrupt more as it ticks down  

Day 10 packed with potential...again

[Lloyds32]

12 minutes ago, That ECM said:

and taking the ukmo and ecm just for balance?

Looks colder but still transient and mobile. Atlantic High Pressure in control. 

[KTtom]

Don't seem to have moved on much in the last 24 hrs, still plenty of promise from ec46, but little signs from the operational and nothing on view you wouldn't get from a routine zonal winter....

BTW nice to come on here in the mornings to get a balanced view from members before the slightly biased members who seem to spend all day hunting for a cold chart get out of bed!

Edited January 11, 2019 by KTtom

[knocker]

The ecm is ding what it gas done in the last two runs, That is amplify the subtropical high around T156 enough that the energy struggles to split it.

From here to saturday the ridge hangs on with fronts struggling to move east with a cold pool developing over the UK and a widespread severe frost on Saturday morning. And through Saturday the energy and the front do manage to remove the ridge and quite possibly some transient snow along the leading edge but obviously at this range mere speculation at the moment;

 

Edited January 11, 2019 by knocker

[SMU]

Very wintry ECM-

plenty of snow kicking about as well- more so for the North & East..

[Cheshire Freeze]

Just now, KTtom said:

Don't seem to have moved on much in the last 24 hrs, still plenty of promise from ec46, but little signs from the operational and nothing on view you wouldn't get from a routine zonal winter....

BTW nice to come on here in the mornings to get a balanced view from members before the slightly biased members get out of bed!

Hard to see how we're going to get a significant Greenland ridge in the near future. But in the EC46 we trust...kinda.

[Roger J Smith]

15 minutes ago, Mizzle said:

Me too. Keep trying to work out what is meant but still not too sure - would someone be able to help me with a brief explanation of a 'slider'?  

Slider is a low moving NW to SE within a deeper trough, along a frontal boundary with arctic air to the northeast, resulting in snow to the north of its track. A "Channel" low might be a form of slider in some cases, but refers more to any low that runs west to east near the Channel, with snow on its northern flanks. 

While we're at it, toppler refers to short-lived north-south high pressure ridges that fall southeastward and change the flow rapidly from cold northerly to milder southwesterly. 

And polar low refers to any small-scale but vigorous circulation embedded in a cold northerly that could produce locally heavy snow as it moves south to southeast (some current examples can be seen near Norway).

Faux cold if you run into that term refers to low mean temperatures that occur when near-to-UK high pressure stagnates and radiational cooling produces arctic-air-mass like temperatures but uppers are not conducive to snow if a front appears. 

 

[That ECM]

2 minutes ago, Lloyds32 said:

Looks colder but still transient and mobile. Atlantic High Pressure in control. 

Therefore an opportunity for lowland north and east to see snow imo. I have little in this initial game, a northerly, North westerly and even to lesser degree a north easterly rarely delivers for this part but if I was in the north or east I would be encouraged by the t144 output this morning. We, down here, will wait and be patient because we always watch others enjoy before we get our fun.

[knocker]

Intriguing first week of Feb with the EC46 with a pattern seen previously in the last few months. A negatively tilted  north Canada vortex and ridging into Iceland/east Greenland. Ergo tending to a split flow of the still vigorous energy exiting the eastern seaboard with the main flow running south of the aforementioned complex. Fine margins

Edited January 11, 2019 by knocker

[Ali1977]

If the EVM isn’t a cold outlier we can assume late next week into the weekend is still looking good for the first decent snowfall in places, obviously if it’s warmer than many of the ENS the further that snow risk migrated south etc...The METO mention snow risk late next week so no reason to think we will be too far from the ECM at the worst!! 

[winterof79]

Another morning of reading the thread and gleaning nothing as moods determine model output.....

Looks fine to me UKMO 144Z and ECM as slider moves through.All good.

[northwestsnow]

27 minutes ago, Steve Murr said:

Very wintry ECM-

plenty of snow kicking about as well- more so for the North & East..

Looks very snowy across much of the north by day 10...

[Cheshire Freeze]

Just now, northwestsnow said:

Looks very snowy across much of the north by day 10...

-6 uppers should be conducive for snow anywhere above about 100m.

[northwestsnow]

Just now, CreweCold said:

-6 uppers should be conducive for snow anywhere above about 100m.

Iv'e seen the much derided EC snow depth experimental and it shows lots of snow, but west of the m6 snow shield fully operational..  (western north west England)

[Mizzle]

25 minutes ago, Roger J Smith said:

Slider is a low moving NW to SE within a deeper trough, along a frontal boundary with arctic air to the northeast....

Thank you so much @Roger J Smith you are a

[Tom Quintavalle]

Having watched both the 00z GFS  (parallel run) (which seemed to take forever) and 00z ECM run come out in full, I remain very positive regarding our chances of some cold, wintry weather arriving in the U.K. My mind harks back to a telephone conversation I had with local Meteorologist, Ian Currie, on Saturday evening.  Mr.Currie suggested that a significant pattern change was on the cards for around 20th/21st Jan, Having viewed all the overnight runs, I would suggest that Mr.Currie isn't going to be too wide of the mark, with his thoughts. He felt that Arctic air would attempt to flood down across the U.K., in stages. He didn't foresee strong blocking over Greenland but the pattern change would involve a strong ridge from a mid-Atlantic High, with low pressure diving S.E, down it's eastern flank. Both the above Models show attempted Northerly incursions from about 14th/15th Jan. Mr.Currie did suggest, it may take a few "bites of the cherry" before a Northerly succeeds.

Having looked at the overnight runs, these Northerly attacks seem to want to begin around 14th/15th but are just glancing affairs, at first. But each subsequent attack seems to be backing the Synoptic pattern a little further westward, each time.

He did also state that he thought that any Scandinavian blocking, was more likely as we enter February and not before

The 00z ECM finished on a very interesting note with a trough disrupting over the U.K with another ridge of High Pressure about to be thrown Northwards, in mid-Atlantic. Obviously way off in the distance and very much speculation but if this kind of situation were to unfold, it's possible we may start to see tentative signs of height rises, to our N.E.

Regards,

Tom. 

 

 

 

Edited January 11, 2019 by TomSE12

[mb018538]

Just looks like a higher ground event to me. Can't see any widespread snow at lower levels in the short to mid term output on offer this morning. Showing 5-6c maxes here, which is just normal for January. The wait goes on...

[karlos1983]

Not really what I was hoping to see this morning, but why buck the trend of morning misery from NWP... bloody hard work this is... UKMO is ok, but I’m not sure how prolonged any cold would be there, ECM is a bit of a mess really, GFS(P) still trying to figure out its gender. 

To coin a phrase..... more runs needed 

[Newberryone]

One can only hope the commencement of these northerly incursions from around the 14th/15th will eventually lead to something more substantial in terms of sustained blocking. Can’t honestly say I find the wording on the latest outlook from the met service here to be overly interesting. This for example is how they see things panning out from next Wednesday onwards..

”Further outlook: A changeable more mobile Atlantic regime is probable, with damp or wet and windy episodes, alternating with drier and brighter interludes. Temperatures will tend to trend closer to average, with an increased risk of night-time frosts” 

[tight isobar]

Everything this morning continues the route -COLD-THEN COLDER..

Again ironing out smaller exactions remain the only BIG issue.

And the fact of the evolving bigger picture(interms of blocks/placements/depths of formats -as a whole)....

Deep jan, continues to open the freezer door even wider.....!

 

[Guest Delete Me]

I think next week will see a brief / failed northern incursion that will set the tone for a successful attempt around the 21st

[Duane S.]

It certainly is a slow old burner.

Robust heights from ridging northwards has not and remains not a viable option for the foreseeable. We need the Arctic profile to fall right for us. It could and If it does, it could be spectacular. If not we may need to sit out the rest of January and put up with tranisent snow events, mainly confined to the hills. I wouldn't be surprised to see a massive cold plunge for North America though, come the final third of the month. Reprocussions of that could go either way!

Anyway, with the ongoing SSW and strat dispruption in general + likely Pacific forcing into Feb,  I just don't see a return to full on zonal mobile for the remainder of the winter. Plenty of hope for February and March. Each to their own, but I would happily take a repeat of last year please.

But for January, I will continue to put my hope in the evident model entropy.

[karlos1983]

Ok that’s cleared a few things up at least.

ECM loses its way around D7.. 

southern England 

Edited January 11, 2019 by karlos1983

[Roger J Smith]

We seem to have this long-lived Euro high on the ropes and hopefully it will be down and out by late next week. Attempts to revive it on some models appear a little dubious but never say never, I suppose. 

As for the cold regime, it would be nice to turn the wrench one more revolution, the thicknesses fall to acceptable but not astonishing values. Last Feb-Mar we saw values as low as 504 dm, and most would consider 516 dm the onset of severe wintry cold and snow guarantees for low elevations, 522 dm is fairly conducive to snow but with mixing issues near sea level in maritime flows, and 528 dm can drop snow on hills but rarely at lower elevations. So I notice that some of the colder days on GFS approach 520 dm thickness values, it's all a lot better than this mild Atlantic garbage (to quote a famous NW person) but we can hope for upgrades. The low now moving inland over northern Norway is unusually deep for a low tracking in that direction up there, perhaps it's a sign that events are moving a little faster than the models have sussed out and we'll see little nudges in the right direction later.