Model output discussion - The run up to Christmas

[Scott Ingham]

10 minutes ago, Captain Shortwave said:

ECM day 6

 

Pretty impressive how tightly clustered the operationals are, even at six days out on an evolution that is not normal for winter. 850s are around -4c, modest but other parameters would draw the freezing level closer to surface level.

850s at closer inspection further north are between -4 and -6 these are down about 1 degree roughly since yesterday they are upgrading like christmas. Make no mistake if we get anywhere near -7 this could be a very snowy period. Its unfolding closer to time. Expect troughs etc as well due to low heights. Every reason to feel excited even if we get no snow it will have been fun!

[goosey007]

8 minutes ago, I remember Atlantic 252 said:

around -4, could be enough with low thicknesses, but as always hills favoured

At this  range these famous 'uppers' can always get upgraded or downgraded by a degree or two, depends how you see it...if so alot of people going to get a good dumping ❄

Edited December 21, 2020 by goosey007

[NewEra21]

The trough is just too deep/ball shaped, meaning we can't really pull any cold air down from the north. It's just like a washing machine spinning around and around and mixing out any cold air.

[Allseasons-Si]

2 minutes ago, TSNWK said:

192 worries me.. definite trend across the board for amplification into Greenland to soften.. now do we topple at 216 or head east...

There is more amplification upstream off NE states so i wouldn't worry at all.

[cheshire snow]

1 minute ago, Scott Ingham said:

850s at closer inspection further north are between -4 and -6 these are down about 1 degree roughly since yesterday they are upgrading like christmas. Make no mistake if we get anywhere near -7 this could be a very snowy period. Its unfolding closer to time. Expect troughs etc as well due to low heights. Every reason to feel excited even if we get no snow it will have been fun!

Certainty will please post the video of that man running naked around Rotherham 

Nice to see all three main models in agreement at T144

C.S

[Cheshire Freeze]

3 minutes ago, TSNWK said:

192 worries me.. definite trend across the board for amplification into Greenland to soften.. now do we topple at 216 or head east...

192 looks good to me...NW-SE jet axis across the Atlantic and a huge block to our E that would likely spell the end of the SPV

[Kasim Awan]

2 minutes ago, NewEra21 said:

The trough is just too deep/ball shaped, meaning we can't really pull any cold air down from the north. It's just like a washing machine spinning around and around and mixing out any cold air.

Yeah, ukmo and ecm are like this.. Mixing is a valid worry more so with a larger low. Don't forget the gfs has been leading the way here. It could well be right in it's smaller low.

[Methuselah]

43 minutes ago, AdrianHull said:

Any chance of an uppers output discussion thread mods? 

This is starting to get tedious!

Don't worry, mate... no-one will be fined should you choose not to attend!

[That ECM]

Another run and another possibility. I would like this to be the way forward.

[Mike Poole]

Just now, Kasim Awan said:

Yeah, ukmo and ecm are like this.. Mixing is a valid worry more so with a larger low. Don't forget the gfs has been leading the way here. It could well be right in it's smaller low.

Yes, that’s a factor, the GFS is normally infamous for overblowing low pressure systems.  

[Matt H]

5 minutes ago, TSNWK said:

192 worries me.. definite trend across the board for amplification into Greenland to soften.. now do we topple at 216 or head east...

Looks like there’s renewed amplification at t216.

[Kasim Awan]

The NW-SE jet axis has been plauged by models for a few days. It certainly isn't a negative given the mid Atlantic ridge is signalled to reattempt amplification.

[Kasim Awan]

216 BOOM.

Edited December 21, 2020 by Kasim Awan

[Allseasons-Si]

216...

As i have just stated ^,upstream looks good

[TSNWK]

6 minutes ago, TSNWK said:

192 worries me.. definite trend across the board for amplification into Greenland to soften.. now do we topple at 216 or head east...

216 I like it., yes I know the uppers., but it looks slack we might developing our own cold at surface by then and yes upstream looks primed.. I’m going to make my 1st prediction.. 240 will pleasing and that inlcludes uppers

[Notty]

1 minute ago, Frosty Winter said:

Looks like there’s renewed amplification at t216.

More cold air on the way - 

WWW.METEOCIEL.FR

---

Meteociel propose le modèle deterministe de ECMWF CEP

 

[Lampostwatcher]

216

ECM 

Fantastic ❄❄❄

[V for Very Cold]

1 minute ago, TSNWK said:

216 I like it., yes I know the uppers., but it looks slack we might developing our own cold at surface by then and yes upstream looks primed.. I’m going to make my 1st prediction.. 240 will pleasing and that inlcludes uppers

The 216 is a thing of beauty... should be printed and framed! 

[SMU]

Pretty ropey ECM tonight apart from the marginal snow event @168 its very tame.

Lets hope its for the scrapper.

Edited December 21, 2020 by Steve Murr

[Matt H]

Day 10 could be better. It’s still cold with a sign of heights rising to the north of Iceland but not as good as previous runs.

Edited December 21, 2020 by Frosty Winter

[NewEra21]

2 minutes ago, Kasim Awan said:

Yeah, ukmo and ecm are like this.. Mixing is a valid worry more so with a larger low. Don't forget the gfs has been leading the way here. It could well be right in it's smaller low.

Yeah hopefully the GFS is correct and we see the other models showing a smaller low in the days to come.

A smaller and more stretched out low would give us a chance to draw some more cold air in from the north. With these ball shaped lows we have nothing to draw on and they just mix the cold out.

[Mike Poole]

ECM T240:

Air gradually getting colder but it is taking time, but you can see upstream that reamplification is going to keep occurring and temperatures will become colder.

[Allseasons-Si]

ECM At 240...

if it doesn't snow from now into Jan,..then i will join @Scott Ingham

[Catacol]

46 minutes ago, Nick F said:

Check out the expanding high dropping down from Russian arctic / Siberia to China and Mongolia, pressure rising to 1076 hPa! That's going to kick off some strong East Asian Mountain Torque.

The SPV in serious trouble ...

I think it is doomed. The only issue now is whether it will feature a full split or not and for how long it may reverse. Unlike Snowy Hibbo I think the reversal is important for the U.K. and chances of severe cold. Still a way to go before we will know for sure...

[Daniel*]

Not sharing enthusiasm at all about ECM 12z more wet than white day 6-7 determines how much cold air we can get the low is like a bowling ball on this run and gets stuck over us. Let’s hope it’s an outlier.