Model Output Discussion - Colder but how cold and for how long?

[ANYWEATHER]

Could be throwing the towel in a bit early, but I think the up and coming cold spell should be really enjoyed next week, both models show the Atlantic coming in. I know that's a long way off ,but it's the default of the Uk weather ,and with no proper blocking in situ over the UK,  I say enjoy the snow if you get it, the snow risk for the south has now faded ,which is no surprise. Hope the gfs and ecm tame down the eventual Atlantic onslaught , we could do with weeks of cold and dry weather, if gfs is right we are back to flooding problems and wind damage, hopefully it's wrong......☺

[Weather-history]

18 minutes ago, northwestsnow said:

Breakdown is such a horrid word..

I much prefer upgrade and after seeing cluster 1 and MOGREPS this morning I suspect today will be a good day for coldies !!

ECM 0z seems to have pushed back the "breakdown" or "warming up" on the ECM 2m temps for Manchester

Look at Sat 20 Jan on yesterday's ECM 0z

Now compare with todays 0z

Notice the box has tightened up for Saturday, less milder ensembles for that day

Also note the median line for Sunday is on the red line for yesterday's 0z but on today's 0z its below the red line.

Minute detail, but if you want the cold spell to extend, you want little things like this to appear.

Edited January 12 by Weather-history

[Cymro]

2 hours ago, MKN said:

That is the most likely outcome and always has been. Everyone always gets carried away by charts 180 hours away etc. Northerly outbreaks rarely produce for the majority of the UK except for those in the far North. 

This is incredibly incorrect, Northerlies produce much snow for Scotland, Northern England, Northern Ireland, Wales, SW England and Eastern English coastal areas. The only areas that tend to struggle are central areas 50miles inland from the sea. 

But entrenched cold from Northerlies set up conditions ripe for battle ground snow across large areas of the British Isles. 

The monotonous claim about lack of precipitation and it will be dry are almost always unfounded and snow chances pop up - take a break from the models until Sunday, it will be a different picture by then, with snow chances in this set up a plenty! 

 

 

Edited January 12 by Cymro

[Fitzwis]

24 minutes ago, Nick F said:

There is a chance, as GEM shows, that the Atlantic upper troughing / surface lows disrupt more and slide SE against the cold airmass over the UK weekend of 20/21st. UKMO looks like it could head down that route too after t+168. 

Not a great deal of support from GEFS postage stamps. But still time for changes towards Atlantic trough disruption. But the return of westerlies weekend of 20/21 looks more favoured for now. 

Snow event looking likely for parts of Scotland and perhaps N England on Tuesday, as that low that forms south of Iceland in the arctic flow tracks SE towards northern Britain. Also snow showers for far north and coasts exposed to the N or NW Flow. EC has snow event back on the menu for S England Weds/Thurs next week, GFS a near miss, UKMO and GEM well south over France. Could be more back and forth on this front, though suspect it will end up south of S England. 

Cold all next week, but away from the north, can't see a great deal to get excited about if you want snow, unless the low off the Atlantic tracks further north than suggested. I see the 'but features can pop up at short notice' comments, but nothing to suggest anything popping up other than the Channel low threat for now.

Potentially the perfect set up for us here in Jersey then. Although as you well know, being a little rock 9x5 miles surrounded by sea currently at a barmy 10c, it's very touch and go. As long as the air across the continent is cold enough and we tap in to an E to SE feed, it's game on :)

[North Easterly Breeze]

12 minutes ago, Buzz said:

Certainly something to keep an eye on, I've experienced a few good events from danglers in the past.

I think we’d all like to experience a dangler or 2 over the coming week. 

[Mike Poole]

ECM extended clusters T264+:

If we recall in the previous timeframe the majority cluster 1 rebuilt the ridge - to do this it needed some WAA into Greenland, and this came from developing a powerful system on the ESB.  Not really focusing on details here, because lots of runs in this have probably got the early evolution wrong, but the trend here seems to be for that system to move east, and push up a ridge ahead of it, you can see on clusters 1,2,3,4 - but you can now see how this could end up as a Scandi high, cluster 4 the closest.  If the earlier cluster 1 was right, one might expect this signal in the extended to get stronger.

[ANYWEATHER]

15 minutes ago, Severe Siberian icy blast said:

There's just no point at all at analyzing charts regarding a break down when the models have been finding everything too much with little to know agreement, but the cold is coming. 

People obsessing on a breakdown before its began is baffling but each to their own...

Anything removing heights and cold with ease i suggest caution.

We've got some new dater flooding into the models with the fresh influx of spikes in background drivers, further +MT events ,  favourable wind influx pushing north from the tropics and a high amplified mjo should keep us all interested but its draining in this place every morning people obsessing on every model output even read a few posts saying basically what cold spell, it's all abit pathetic tbh that particularly with the morning blues people making comments based upon a chart thats 192 hours away when we can't even get it right for 4 days away! 

A relaxation around the last 5 days of the month or so maybe but can see a snowy breakdown and a temp blip in conditions before renewed bouts of wave breaking keeping the jet amplified but pushing south and another 12 rounds for the mighty vortex that's been knocked from post to post this year already and with the El Nino imprint one of the big drivers a back loaded winter looking very interesting in deed! 

I would urge caution, though as regards this cold spell and it's longevity.  The Atlantic is the driving force or dominant weather throughout the seasons more or less, so while the cold spell is welcome and dry weather is well needed, I think the writing is on the wall, with no proper blocking of cold across the nation.  If it stays dry until next weekend or so , for my location it will be over two weeks of no rain, could do with two months , but a pattern change is not unexpected.

[JimBob]

1 hour ago, January Snowstorm said:

Awesome charts this morning with the depth of cold upgrading big time!! Ice days and widespread snow now becoming more and more likely!! Fair play to Met Office again! Widespread disruption likely by as early as Tuesday!!

I think you are seeing what you want to see, no widespread snow on the charts. 

[MJB]

1 minute ago, JimBob said:

I think you are seeing what you want to see, no widespread snow on the charts. 

I don't see widespread snow at all. 

To say there is, is very misleading 

[geordiekev]

1 hour ago, Gowon said:

With all these chases Ambassador you are spoiling us

[Vikos]

Confucius says learn from the past to know about the future (or something like that)

EC 10 days ago for today 

 

today’s 0 chart

 

Same for GFS

Today’s chart 

 

Edited January 12 by Vikos

[Rob 79812010]

Does anyone know why gefs ensemble 850 graphs keeping weather at average from 23rd to 28th? Isn't that against everything we're seeing??

[Sparky68]

2 minutes ago, geordiekev said:

With all these chases Ambassador you are spoiling us

That model reminds me of the Robot from "The Day the Earth Stood Still" Could be a sign 

[MJB]

So close yet so far.......................a near miss. look at the purples across Belgium 

[northwestsnow]

1 minute ago, MJB said:

So close yet so far.......................a near miss. look at the purples across Belgium 

It may move north yet...

[Jackski4]

From a selfish perspective I want this low as far south as possible, keeps the cold locked in longer and in my location it looks like we’ll get some streamer activity off the Irish Sea. And usually these type of things do always trend south although much to be resolved still..

[Man With Beard]

3 minutes ago, MJB said:

So close yet so far.......................a near miss. look at the purples across Belgium 

I appreciate it doesn't happen every time but I'm always mindful of January 2010 - the time the entire country (except Bournemouth!) went white due to a feature only modelled within T48 - and that was on a northerly.

[Singularity]

The ultimate level for week 2 forecasting is correctly anticipating the impacts of model bias, which can strongly skew entire ensemble suites.

Alas, that’s a lot easier said than done!

I sure can see how GFS & ECM might be incorrectly presuming a more traditional route for the westerlies associated with the initial stages of rising AAM (a.k.a. lagged impacts of AAM having recently fallen to near neutral). In short, if enough residual heights hold on at the high latitudes via lingering easterly momentum anomalies, the strengthening polar jet will be redirected into S Europe instead of N.

It is inevitably an ‘if’ but the point is, it has more chance of happening than the ensemble products currently suggest.

In other words, best keep an open mind as to what may happen even on the broad scale later next week & through the one after.

[BLAST FROM THE PAST]

48 minutes ago, offerman said:

Hi Blast,

Can you post a link for me please to that graphical chart UKMOffice chart. Thanks 

Meteociel

 

BFTP

[festivalking]

While some well look to the following weekend for what happens next I'm still paying attention to the channel low for mid week, still very much in the balance

UKMO det considers the low will hit northern France and miss the south entirely.

Quick look at mogreps suggests its not clear cut. Half the 850's go above freezing in plymouth suggesting the low will push further north. A few go above in Brighton. Again look at Cardiff a couple of runs head above 0 with say 40% rising from -10's towards but not above 0. Same for Birmingham.  Still a chance the south will get the clear see through typesnow with the purple patch along the M4.   As such those discounting the channel low may yet be surprised as its not a done deal by any means.

 

Edited January 12 by festivalking

[icykev]

52 minutes ago, offerman said:

Hi Blast,

Can you post a link for me please to that graphical chart UKMOffice chart. Thanks 

WWW.METEOCIEL.FR

---

Météociel propose le modèle UKMO jusqu'à 168h. Cartes de prévision des précipitations, du vent, des températures

 

[Troubleatmill]

7 minutes ago, Man With Beard said:

I appreciate it doesn't happen every time but I'm always mindful of January 2010 - the time the entire country (except Bournemouth!) went white due to a feature only modelled within T48 - and that was on a northerly.

And Preston

[adrianh]

Current modelling shows that snow chances are largely for those in the North West and potentially for the south if the path of the low is optimum. However there is always the chance of smaller disturbances delivering over the next week and there'll no doubt be some surprises cropping up within the shorter timescales.

[The Enforcer]

14 minutes ago, Man With Beard said:

I appreciate it doesn't happen every time but I'm always mindful of January 2010 - the time the entire country (except Bournemouth!) went white due to a feature only modelled within T48 - and that was on a northerly.

And it went from a M4-south event to an M40-south event within T+12.

[TEITS]

4 minutes ago, northwestsnow said:

It may move north yet...

Cannot be ruled out. However some models have now trended this low so far S that even N France misses out with more central parts of France being at risk. Such a shame as I would of loved to see some of those snowfall predictions come off for my location. This isn't surprising though as I expected the shift S.

Beyond next week and the outlook is as clear as mud. I'm sticking with the remaining cold outlook but turning more unsettled. A cold, zonal spell with the jetstream tracking much further S than normal. Still cannot rule out an E,ly though as we could see surface highs deflect low pressure systems SE.

I sincerely hope some of the model runs are wrong ,as some suggest an extremely windy, wet spell which would cause massive flooding issues again.