Model Output Discussion - cold spell to end Autumn

[bobbydog]

Just now, karlos1983 said:

It has helped, some parts of the country could get buried from that run. Best run for years never mind Winter Karl 

now lets hope the weather... plays ball... 

[BLAST FROM THE PAST]

ECM......wham, bang, thank you Mam.   Incredible run and will produce lots of disruptive snow.  The continued trough disruption/ slider tendency is the thing to watch for continued cold.....and there is lot’s of cold to tap into

BFTP

[Ian Francis]

13 minutes ago, Bring Back1962-63 said:

I think that you may well be right about the 850s record for "early" December cold spells - let's say the first half up to Dec 15th, although there is an example of a lower reading in late November 1890 with -18c 850s in south-eastern England (see the 5th chart below). Before I go further........................

Thanks for that excellent post BB1962-3

 

[Met4Cast]

I think we need to be cautious re: ECM. It's hardly covered itself in glory these past few days, lets not suddenly back it because it's showing us what we want. I'd like to see some consistency from it for a change before I get excited.

GFS/UKMO very good in the long term too, very good charts with a lot of potential for widespread snow.

[karlos1983]

That thickness, those uppers = snow machine

And we aren’t just talking coastal showers, these would spread well inland I’d imagine.

Edited December 2, 2017 by karlos1983

[Frosty.]

5 minutes ago, Danny* said:

I think we need to be cautious 

Absolutely but I think the arctic blast from thursday to next weekend is nailed so coldies have that to look forward to with snow showers and frosty / icy nights. It's a question of how long it lasts which is currently uncertain. Overall I'm over the ? with today's output..loving every minute of it!☺??

[The Enforcer]

24 minutes ago, Danny* said:

I think we need to be cautious re: ECM. It's hardly covered itself in glory these past few days, lets not suddenly back it because it's showing us what we want. I'd like to see some consistency from it for a change before I get excited.

I agree entirely, the likelihood of further changes at the 8-day range seems very high and possibly not favourable ones. I am not keen on north-west to south-east sliders anyway. As shown, it looks to me that there is too big a mild sector with 850s widely higher than -5C on the charts that Frosty posted. I suspect that the dew points would be too high as well. The required westward corrections then could mean the snowy part of the system missing most or all of the U.K. A slider attack from the south-west would be much lower risk.

The GFS/UKMO have a more snowy forecast for day 5, so I would prefer the next ECM run to provide stronger support for those at that point, rather than continuing to randomly generate/drop random snow events at the latter half of its run.

Edited December 2, 2017 by The Enforcer

[feb1991blizzard]

5 minutes ago, karlos1983 said:

That thickness, those uppers = snow machine

And we aren’t just talking coastal showers, these would spread well inland I’d imagine.

There would be a longer outbreak of heavy snow on the Northern flank, anyway the EPS are an upgrade on the last suite, slightly more defined Atlantic ridge and low anomaly to the East and if anything strengthens the mean -ve temperature anomaly across UK right out to D15.

Edited December 2, 2017 by feb1991blizzard

[karlos1983]

5 minutes ago, feb1991blizzard said:

There would be a longer outbreak of heavy snow on the Northern flank, anyway the EPS are an upgrade on the last suite, slightly more defined Atlantic ridge and low anomaly to the East and if anything strengthens the mean -ve temperature anomaly across UK right out to D15.

Brilliant!

[CanadaAl]

Looks like downgrades on the 06Z and the 12Z from last nights pubs runs (18Z and 0Z) eagerly waiting for the 18Z to see where it's heading. ECMWF is a thing of beauty!

[Met4Cast]

Just now, CanadaAl said:

Looks like downgrades on the 06Z and the 12Z from last nights pubs runs (18Z and 0Z) eagerly waiting for the 18Z to see where it's heading. ECMWF is a thing of beauty!

Are you looking at the same runs as everyone else?

[LRD]

8 minutes ago, The Enforcer said:

I agree entirely, the likelihood of further changes at the 8-day range seems very high and possibly not favourable ones. I am not keen on north-west to south-east sliders anyway. As shown, it looks to me that there is too big a mild sector with 850s widely higher than -5C on the charts that Frosty posted. I suspect that the dew points would be too high as well. An attack from the south-west would be much better.

To be fair it was NW to SE sliders that gave me (and many others) my last true wintry spell - January 2013. Nearly 5 years ago. I know the north did well in March 2013 from a more defined cold pattern. I find sliders to be more reliable than straight Northerlies

[Tracy Flick]

40 minutes ago, knocker said:

Will it cut off the jet?

Probably the first time I've not wanted the jet to be cut off.

[Eskimo]

We mock the GFS at times, but it predicted the low next thursday/friday 12-14 days in advance, which to be fair...is incredible. Here's a toast to the GFS! 

[CanadaAl]

1 minute ago, Danny* said:

Are you looking at the same runs as everyone else?

Yeah I should of said, at the +192 range. It's not a full Atlantic onslaught but we're not seeing heights that we did over greenland/scandi. Still very good <192 range. 

[Winter Hill]

Hi all, new here. Just a question. Why is everyone getting excited over a northerly ? 

I mean the wishbone affect will be evident and apart from the coastal areas, the rest of us will be basically cold & Dry.

I've only been following the models since the fabulous February 2009 outbreak which saw many areas of the UK hit by heavy periods of snowfall. From that day I've always thought that the metO was top dog. I personally think if we get to T+96 then the Euro models will not be far wrong.

Here to facinating period of model watching and hopefully a white Christmas... not seen since 2010.

Winter hill.. 

[markw2680]

4 minutes ago, CanadaAl said:

Looks like downgrades on the 06Z and the 12Z from last nights pubs runs (18Z and 0Z) eagerly waiting for the 18Z to see where it's heading. ECMWF is a thing of beauty!

Sorry but think your having a mad moment tbh

[I remember Atlantic 252]

2 minutes ago, LRD said:

To be fair it was NW to SE sliders that gave me (and many others) my last true wintry spell - January 2013. Nearly 5 years ago. I know the north did well in March 2013 from a more defined cold pattern. I find sliders to be more reliable than straight Northerlies

Depends, they need to get far enough west, this one tracked too far East, and gave a dumping to the East Midlands, and rain/thaw here

[Allseasons-Si]

1 hour ago, bluearmy said:

Did anyone spot a wedge ??

Yes!!!

some stonking outputs/models again today

 

[Mokidugway]

1 minute ago, Allseasons-si said:

Yes!!!

some stonking outputs/models again today

 

I believe the SPUD model isn't very reliable 

[A.J]

1 hour ago, Mokidugway said:

I would imagine Wales getting a pasting from lake effect snow off the Irish Sea streamer from the northerly .

sadly being here 'darn sarf', it'll probably rain first, so the best I can hope for is 'Puddle-Effect Snow' 

Edited December 2, 2017 by ajpoolshark

[The Enforcer]

6 minutes ago, LRD said:

To be fair it was NW to SE sliders that gave me (and many others) my last true wintry spell - January 2013. Nearly 5 years ago. I know the north did well in March 2013 from a more defined cold pattern. I find sliders to be more reliable than straight Northerlies

I thought that one approached from the south-west and tracked pretty much due east. If it is the snow event I think it is, I seem to recall it happening on a Friday and it gave a reasonable covering here too. It's always been from the north-west since then and a failure every time due to inadequate dew points.

[I remember Atlantic 252]

1 minute ago, The Enforcer said:

I thought that one approached from the south-west and tracked pretty much due east. If it is the snow event I think it is, I seem to recall it happening on a Friday and it gave a reasonable covering here too. It's always been from the north-west since then and a failure every time due to inadequate dew points.

This one? was unexpected great event here

[Sparkiee storm]

Because I wasn't round here since the big freezes of 2009 - 10 and 2013, is this what a big freeze looks like on the models especially the GFS and ECM ? 

[nick sussex]

Tonight’s ECM is a good example of how to get some snow without a strong block.

As long as the jet angles se into the UK with those weak heights to the ne you can get some interest.

Both the ECM and GFS are very close in terms of pattern. The UKMO is similar although less clear over the ne USA.

NOAA alluded to the complexity of how shortwaves will run east and engage the trough and how this would impact its amplitude and then how that energy gets directed into the Atlantic .

The overall pattern is expected to last just the more local detail is still prone to change.

The ECM has certainly gone from Scrooge to Santa in the space of 12 hours!

Edited December 2, 2017 by nick sussex