Model Output Discussion - cold spell to end Autumn

[Frosty.]

Stunning snowmagheddon  Gfs 18z tonight..so many great charts, here's my pick!..magic!

[I remember Atlantic 252]

can it get far enough west?

[feb1991blizzard]

3 minutes ago, Steve Murr said:

The angle of the jet at 192! Look like ptb 3 from earlier - very steep gradient

Yes agree, however, I doubt many people in England would care by this stage, the pressure would be off, as we would still be under a foot of snow.

[nick sussex]

Without the phasing with the now almost filled out low near Denmark the low to the nw could have become a slider with the winds ahead staying just sufficiently se.

That little area of weak positive heights to the ne could yet play a role.

[Thunder Snow]

19 minutes ago, andymusic said:

gfs 18z shifted the arrival of the cold 850s forward another 6 hours or so

wow looks good even for me 

[northwestsnow]

Jeez i hope EC looks like this tomorrow...we will be down to day 5 by then surely to God GFS wont be far out at this range..

 

[SMU]

21 minutes ago, Ice Day said:

I take it this is what you're referring to Steve?  It doesn't get much steeper than this!

Fast forward 12-18 hours & look at the atlantic jet !

if this occurs UK wide freeze would continue + 2-3 more days

Edited December 1, 2017 by Steve Murr

[markw2680]

For me one word is enough....pummelled ?

[comet]

excellent run so far only problem being the adjustment south of the low in just 6 hours from the 12z. At this rate by this time tomorrow we will be wondering what all this talk of snowmagedon was all about when the low is modelled 500 miles or more to the south of the UK.

[Snowman.]

Pocket of heights N/NE reminds me very much of January 2013.

[J-Man]

Just 132 hrs from now.

 

 

Edited December 1, 2017 by J-Man

[I remember Atlantic 252]

deep into FI now, on this run though, shortwave from Iceland area just about far enough west

[Ice Day]

3 minutes ago, Steve Murr said:

Fast forward 12-18 hours & look at the atlantic jet !

if this occurs UK wide freeze would continue + 2-3 more days

Here we go, 222hrs.  No complaints if it stays there for the next 3 months!

[bradymk]

4 minutes ago, nick sussex said:

Without the phasing with the now almost filled out low near Denmark the low to the nw could have become a slider with the winds ahead staying just sufficiently se.

That little area of weak positive heights to the ne could yet play a role.

Yes Nick. Bluearmy said yesterday that the wedge was going to become more apparent and it has. Those weak positive heights to north just helping deflect that jet. I suspect deflect it even more come the reliable timeframe...(hopefully)

[Snowy L]

 

4 minutes ago, J-Man said:

Just 132 hrs from now.

 

 

Plenty of time for the GFS to dump it, bring it back and then dump it again

 

On a serious note, the GFS and UKMO have definitely picked up on something in 7-8 days time. LP taking a nosedive into Iberia on both.

Edited December 1, 2017 by Snowy L

[SMU]

The 18z shows that once you have an upper air cold mixed to the surface & entrenched then the 850s number becomes less important with ice days with -6c values...

Its a delicate juggling act especially with the atlantic dipping its toes back in bit thats how months like jan 63 / Feb 86 / Dec 10 delivered such low CETs - because the cold pool remained in situ at the surface over the UK- 

Slack winds / surface cold & snow cover is the very best ingredients for the UK to generate its own self perpetuating cold pool...

[nick sussex]

You want a slider low here, so the circled red area is a little area of weak positive heights. The yellow circle is the left over remnants of the limpet low. The low heading se phases with that , so no phasing and that little area of heights to the ne could act together to slide the low se and keep the UK in a se flow with lower dew points rather than the phase and change of flow ahead of it.

The GFS still gets it into the Continent and interestingly you end in a similar position to the ECM at T240hrs.

This looks a very strong signal to keep the UK in a pattern condusive to some snow and cold. If both the ECM and GFS have different starts but similar ends at T240hrs then that increases confidence.

[andymusic]

battleground incoming at 324 (just for some more fun)

Edited December 1, 2017 by andymusic

[SMU]

Just to add this chart is the JACKPOT if you want sub -15c minima..

[Ice Day]

2 minutes ago, andymusic said:

battleground incoming at 300 (just for some more fun)

You have to love FI of the Pub Run......it's always good for a laugh

[northwestsnow]

Well meto still talking of wind and rain and wintry showers following behind.

After seeing 18z GFS i would be extremely dis-satisfied with wintry showers...

Pretty please ECM..stop being a bugger your causing my hair to go grey..

[Ross Andrew Hemphill]

Snowlow now further South on the 18z, missing Scotland completely (refrain from moaning since its 6 days out and can still change) 

[Frosty.]

What a sensational 18z..the cold goes on..and on..and on along with a risk of snow, miles better than last nights run..as Ian Brown famously said..WTF  I don't know what to say!!

[ICE COLD]

Greenland high anyone ?. The NH view is still amazing right to the end . If we can't get a cold snowy spell out of this in December then I'm giving up . 

Edited December 1, 2017 by ICE COLD
Typo

[East_England_Stormchaser91]

As I said yesterday, never mind 120 hours being a long time in model output, 36 hours is!! Look how much has changed. Some of the best runs have suddenly erupted out of nowhere. Look at those widespread northerly heights rising now and a true southerly tracking jet with the cold nailed in place. What a stonker of a run, even though it's still way too far out. 

GFS is still keen on that very worrying deep low again however..