Model Output Discussion - Into Winter

[Ali1977]

Bigger high meaning a cleaner colder flow from the NE , maybe more unstable too ️

[Battleground Snow]

Just now, swfc said:

Its just a small run varience. Its to ne expected tbh

No it's not, it has significant ramifications further down the line, it's been slowly inching towards arpege/ukmo

[Scott Ingham]

Gfs picking up a small disturbance running down the east coast that may bring about a centimetre or two in the north east and Yorkshire 

[Ali1977]

Here’s the system on the ECM that showed the snow on Sunday - let’s see what happens

[TSNWK]

1 minute ago, Scott Ingham said:

Gfs picking up a small disturbance running down the east coast that may bring about a centimetre or two in the north east and Yorkshire 

And so it begins.. 48 /72 hour notice pop ups in the flow…

[MJB]

13 minutes ago, Ali1977 said:

It’s about the same, if not further south - could mean more upgrades to the cold 

Beeb have gone with further South but said if further North then it's a snowy story, but think South it is 

[swfc]

3 minutes ago, Battleground Snow said:

No it's not, it has significant ramifications further down the line, it's been slowly inching towards arpege/ukmo

At what timescale 

[legritter]

Hi gang , Thanks to all the posters who contribute to the BEST Forum in the northern Hemisphere. Very interesting Synoptics and the usual Garden paths , I'm usually about a couple of times a day and its great to read your posts .Sausage baps aĺl round and Stella s on ice Cheers gang .

[offerman]

5 minutes ago, MJB said:

Beeb have gone with further South but said if further North then it's a snowy story, but think South it is 

Shame South is to miss out on what so many had said, would be a Thursday snow event.

never mind, it’s really early days in the season. Sure there will be plenty more chances to come. 
we may get some showers popping up that turn into troughs, marching their way from East to west. 

[bluearmy]

At day 5/6, gfs has phased a bit more to the west but the Atlantic trough has better neg tilt that the 12z 

jet better aligned nw/se 

Next system headed ne off the Eeastern seaboard - don’t want that to engage too much with the cold air headed west because that will blow up a big system 

[Allseasons-Si]

20 minutes ago, feb1991blizzard said:

according to eps, mild mid dec not a done deal yet.

2 distinct clusters - mean useless in such scenarios.

I got bored so i got my daughter to do a better job

[Battleground Snow]

8 minutes ago, swfc said:

At what timescale 

Basically effects the entire run, but I was mainly thinking of the 96-144 period

[swfc]

2 minutes ago, Battleground Snow said:

Basically effects the entire run, but I was mainly thinking of the 96-144 period

Strange that has things look a bit off at the 150 hr msrk, for  the worst

 

 

 

[Drifter]

What a weird, weird chart

[gaia rules]

Both ECMWF and GFS  have struggled to forecast the low on Thursday. GFS blew it up as we expected by ECMWF doesnt cover itself with Glory either and still 3 days to go. Here are the last few runs on both to compare.

[TSNWK]

4 minutes ago, Battleground Snow said:

Basically effects the entire run, but I was mainly thinking of the 96-144 period

Although heights looked better in Greenland early doors on this run it’s looking like the Atlantic is making more of it by day 7.. lot less heights ridging in the mid Atlantic

2 minutes ago, swfc said:

Strange that has things look a bit off at the 150 hr msrk, for  the worst

 

 

 

Got to agree with this,., not a good 18z for longevity is the view at day 8 I suggest..

[BartyHater]

Not really liking the 18GFS much either, it appears to be heading in the same direction ICON would have gone, if the 18 extended past 120hrs. 
All looks a bit messy now in the 144-180hr range, what happens thereafter looks like anybody’s guess.

[Wold Topper]

12 minutes ago, offerman said:

Shame South is to miss out on what so many had said, would be a Thursday snow event.

never mind, it’s really early days in the season. Sure there will be plenty more chances to come. 
we may get some showers popping up that turn into troughs, marching their way from East to west. 

We don't all live in the 'South' old bean as you were...

[Allseasons-Si]

Just now, TSNWK said:

Although heights looked better in Greenland early doors on this run it’s looking like the Atlantic is making more of it by day 7.. lot less heights ridging in the mid Atlantic

Better heights NE into Svalvard though,this in turn weekens the trough near the UK and forcing it further south,that bowling ball S of Greenland should weaken to a neg SE tilt in the later frames because of better heights NE,we shall see.

 

[TSNWK]

Just now, Allseasons-Si said:

Better heights NE into Svalvard though,this in turn weekens the trough near the UK and forcing it further south,that bowling ball S of Greenland should weaken to a neg SE tilt in the later frames because of better heights NE,we shall see.

 

I was going to have an early night,., but will stick around for 10 mins more…

[January Snowstorm]

Guys wake me up when something happens!! Instead of a snowfest it's turning into a snoozefest  

[CoventryWeather]

3 minutes ago, TSNWK said:

Although heights looked better in Greenland early doors on this run it’s looking like the Atlantic is making more of it by day 7.. lot less heights ridging in the mid Atlantic

Got to agree with this,., not a good 18z for longevity is the view at day 8 I suggest..

I mean it has a perfectly symmetrical low in the Atlantic, that's pretty much impossible to have! If it weren't for that, I think it would be a very good run. 

Really need to sort that bias out - it's misleading - especially on the short term when it's completely out on its own. It's embarrassing really to think about it. 

[Paul_1978]

2 hours ago, TillyS said:

This isn’t really right Kasim. It was the coldest start to meteorological winter since 2010, not my words but the official Met Office analysis of the month. I remember snow flurries in London.

"The first two weeks of December were the coldest start to meteorological winter since 2010, with high pressure and a cool northerly airflow resulting in a prolonged spell of low temperatures with snow and icy conditions at times, albeit with interludes of clear skies.  

A weather station at Braemar, Aberdeenshire, recorded the lowest daily maximum temperature of the year, with -9.3°C the highest it reached on 12 December. In the early hours of the following morning, the same station recorded the lowest minimum temperature of the year with –17.3°C. 

Mike Kendon is a climate information scientist working for the National Climate Information Centre in the Met Office. He said: “December’s weather will principally be remembered for the notably cold start to the month, with prolonged low temperatures, hard frosts and snow and ice at times, even to areas further south in the UK.  

“This cool weather was principally brought on by an Arctic Maritime airmass, with daytime temperatures struggling to rise above freezing for many in what was one of the most significant spells of low winter temperatures since the exceptional December of 2010.” 

 https://blog.metoffice.gov.uk/2022/12/30/cold-december-concludes-warmest-year-on-record-for-uk/ 

 

Two reasons for posting historic weather in a model output discussion. First, for good or ill, it shows we’ve been here before. It’s not exceptional but it is going to be cold.

Second, it doesn’t mean we’re heading for either a repeat of last year or a 1962-3. It’s too early to say.

What the models are not now showing, at the moment, is sustained northerly blocking. The 12z ECM is an interesting scenario:

 

@ScottSnow that's a high sliding from west to south-west of the uk in the T216 to T240 charts, which is not really what we want to be seeing for sustained cold. It would be brilliant for the Alps mind you. NB @ICETAB maybe ‘toppler’ isn’t the correct word, but transitional high moving southwards would be an accurate assessment of the latter stages of tonight’s ECM on those two charts? Not that it’s necessarily right about that, mind you. It’s one possible route. As someone else just mentioned, there’s a wide scatter in the ensembles so all to play for https://www.netweather.tv/charts-and-data/ensembles

 

You’re not really new here are you?! 

[Mark wheeler]

18z wobbles as usual. On to the 00zs .

[swfc]

Pre 170hrs the second low leaving the Esb on the back of the low in the Atlantic brings in s west to east flow ie Atlantic 

Edited November 27, 2023 by swfc