Model output discussion - The Hunt For Cold

[Mucka]

GFS control. Let's see the vortex get out of that!

We can only hope we get charts like this verify.

Edited November 13, 2018 by Mucka

[carinthian]

3 minutes ago, carinthian said:

The route to cold is indeed from the NE ( see above post earlier ) looking at this latest chart from GFS. Rain turning to snow behind the Arctic Front across England and Wales and what looks like possible Polar Low  between Scotland and Norway. Certainly 500mb temps cold enough at -40c or more with plenty of convection over the sea. Will have access to outer perimeter snow forecasting model tomorrow ( 10 days ) so should be interesting to report back with thoughts from over here regarding the UK and the Alps.

C

Just to point out , it is impossible to forecast a Polar Low that far out but think the model hints that a formation is very possible in that depth of cold and location, especially after the passage of a Arctic front.

C

[bluearmy]

1 minute ago, CreweCold said:

Even if we miss the first bite, at the very least it looks like we'll get a vortex displacement which should aid us into December...best case scenario we have a December SSW to fall back on. The trop has done enough work by this point to almost guarantee us a December response of some kind. How often can we say that?

I think GP is on the same sort of lines.

agreed - the ec is showing a quick route to the cold pool (unlikely to bring snow but you never know). beyond that, we could see a nov 2010 redux or a stable block with a continental feed or a further cycle leading to the greeny/griceland block end of the month

latest gefs 12z around day 11 is a little less amplified to our nw - still impressive 

[Mucka]

Central Britain ensembles

[Cheshire Freeze]

Just now, Mucka said:

GFS control. Let's seethe vortex get out of that!

We can only hope.

The beauty of it is (and why I'm more bullish about this episode), that of course the upper vortex will try and downwell but for now, every time it attempts it will lead to self destruction. Think of it like hovering your finger over the tip of a knife, every time you push down, you get cut.

[ITSY]

N Norfolk coast. First signs of a proper flatline. The party pooper in me says: if it were January the line would be -12 not -5 but the model watcher in me says, given the background signals, this could just be the start. 

[tight isobar]

1 minute ago, carinthian said:

Just to point out , it is impossible to forecast a Polar Low that far out but think the model hints that a formation is very possible in that depth of cold and location, especially after the passage of a Arctic front.

C

Agreed..and should be labeled...as pop-up /polar low..

As a feature!!!

[Decemberof2010]

P12 decides to give us a a be-WITCHing end

 

Edited November 13, 2018 by Decemberof2010

[Kirkcaldy Weather]

4 minutes ago, Iceaxecrampon said:

    hopefully this is the theme of winter 2018/2019 

12z GEFS

control 

P4 

P5  

P12 

P13 

P14 

P20 

[Summer Sun]

GFS para so far is keeping the flow more SE'ly rather than easterly whilst cooling down it's not to the extent of the main GFS

GFS P

GFS

[Geordiesnow]

More signs we may start to see some form of retrogression of the high into Greenland coming into the medium range, this in turns increases the chances of a Northerly which of course is the best direction for cold at this time of year.

I think ignoring the detail, the hope has to be seeing the models sticking to the retrogression and the resulting Greenland high signal. As for the initital cold pool, it does look like it won't be significant but if the cold pool and the air of instability does hit the UK in the right place, we should at least see a bit more of a convective easterly instead of the dull cloudy easterly we are likely too see if the winds does become a true easterly. 

[Summer Sun]

GFS and GFS P still miles apart in how they handle this 

GFS

GFS P

 

GFS P                                                                GFS

 

Edited November 13, 2018 by Summer Sun

[booferking]

Control run doesn't split energy but never fear here comes Azores high to the rescue all roads seem to be leading to Greenland 

[Methuselah]

Talking of detail (not much use at this range, I know) that LP, just to the NW of The Azores might be preparing to run the length of the English Channel; this wouldn't be totally out of the question, as yesterday's 18Z suggested something similar...It would also tie-in with the Met's idea of possibly unsettled weather affecting the South and Southwest?

[feb1991blizzard]

4 minutes ago, Summer Sun said:

GFS and GFS P still miles apart in how they handle this 

GFS

 

 

GFS P

 

 

All roads lead to glory, watch the trough about to drop at 300 on the GFS.

[summer blizzard]

From a back yard point of view the flow needs more of an easterly element to rival the 2010 snowcover here although the proximity of the low center in the north sea may aid vorcity.

But the only comment appropriate within the 10 day range for that run is... my god that's spectacular.

[bluearmy]

gfsp shows that this could easily end up quite a messy evolution to deep cold 

[bluearmy]

1 minute ago, Ed Stone said:

Talking of detail (not much use at this range, I know) that LP, just to the NW of The Azores might be preparing to run the length of the English Channel; this wouldn't be totally out of the question, as yesterday's 18Z suggested something similar...It would also tie-in with the Met's idea of possibly unsettled weather affecting the South and Southwest?

isn't that in the second half of the 16/30 day period ed ??

[Methuselah]

2 minutes ago, bluearmy said:

isn't that in the second half of the 16/30 day period ed ??

I brought it forward, Blue!

Hang on? By the time it reached Cornwall, we'd be on day 17!

Edited November 13, 2018 by Ed Stone

[mpkio2]

This place has been buzzing over the past few days, hasn't it?!

Ain't like the past few days the models haven't been spilling out cold runs with potential or anything!

12z UKMO t144 13/11:

12z GEM t120 13/11:

12z GFS t144 13/11:

12z GFS t240 13/11:

12z GFS t324 13/11:

The PV is completely annihilated!!!

OK, all ramping and joking aside, it does appear that support for a cold end to November (As many posters on here have forecasted for a while - @CreweCold and @BLAST FROM THE PAST) by the models IS in full swing! With current atmospheric and stratospheric shenanigans occurring.....

, a de-coupled trop and strat (Despite a record-breaking zonal wind speed in October) and strong wave transfer in the Indian Ocean taking place (MJO transition 3-4-5-6) and talk of a Wave 2 event occurring (Potentially) further down the line at the end of the month....

Its no wonder the models are spewing out runs like this!!!

BUT!!!

As the previous winters have proven, nothing is set in stone, nothing is guaranteed and anything that can go wrong usually does (Especially for cold weather for the UK!!! ).

Point being, latest GFS 12z run is a beaut and shows a perfect evolution of a retrograde Scandi high to full on Greenland high, which shatters the PV and sends a chunk straight down from the north straight to our little island's shores. Its gotten me HYPED!  And everyone else here in the forums! We all want it to happen, but we must place our feet on the ground! It's a great run, but hasn't support from the UKMO and GEM at the moment.

What's great though is that we have the potential to set-up a cold pattern down the line (I mean Arctic cold!). And even if the 12z GFS doesn't come off, at least we'll have more bites of the cherry and it will feel seasonal for the time of year.

Watch the models, see what gets support, where the TRENDS our going!

And the TREND this far is cold!!!

~mpkio2~

[Mike Poole]

Few snapshots at T240 from the GEFS 12z

Particularly like P5, noting ridge on opposite side of the NH, high pressure over pole!

[karlos1983]

Good grief, just when I thought it wouldn’t get any better the GFS goes and does this! Gob-Smacked!

come on ECM, play nicely we’ve all had a good day

[Mike Poole]

Warm air advection towards Iceland looks both immense, and very similar to GFS at T96, this run is going to be good, I think, comparison, ECM first:

Edited November 13, 2018 by Mike Poole

[feb1991blizzard]

3 minutes ago, Mike Poole said:

Warm air advection towards Iceland looks both immense, and very similar to GFS at T96, this run is going to be good, I think, comparison, ECM first:

Sharper on GFS.

[ALL ABOARD]

Come on you can do it .


NOPE not on this run..

Edited November 13, 2018 by ALL ABOARD