Model output discussion - deep cold inbound?

[I remember Atlantic 252]

4 minutes ago, sheikhy said:

Gfs mean more slidey at 162 hours

Aye, control good! my guess is, first front will end up in France hopefully keeping N sea snow going into Thurs/Fri

[Phil Blake]

8 minutes ago, Battleground Snow said:

-14 uppers into the east on the para at 150.

This is definitely a beast.

 

I only see -10s with -12 clipping south east or are my eyes deceiving me

[radiohead]

Just taking a moment to appreciate an amazing EC ensemble mean chart for 144 hours.

Edited February 4, 2021 by radiohead

[feb1991blizzard]

1 hour ago, bluearmy said:

I think that’s pretty disingenuous. Gfs was the model that sniffed the Iberian low pushing quickly northeast to engage our sinking low over the Low Countries. It just made a mess of that interaction and had it a little too far west.  The experience watchers on here dismissed the mess it was making of the meeting of the two air masses but were cautious about ignoring it completely. and they were right to do that. 

The much maligned GEFS were good IMO picking up the signal, ok they messed about at the shorter timeframe shifting the mean forth an back about 2 or 3 degrees over 1 suite at times but that was just a wobble really, most of the time they were rock solid before the EPS fully came on board.

[radiohead]

3 minutes ago, Phil Blake said:

I only see -10s with -12 clipping south east or are my eyes deceiving me

A little later in the run,  -14 almost touches the coast.

[BLAST FROM THE PAST]

58 minutes ago, That ECM said:

Still seeing the trend.  Met have dropped Bournemouth 2 degrees for mon Tuesday wed. 2 max now.

And for Bournemouth to be 2c that is really cold.  Sub zero for many 

 

BFTP

[Battleground Snow]

Can see visually here the difference compared to the 00z run... Breakdown held back for sure.

[DanDorsetUK]

3 minutes ago, BLAST FROM THE PAST said:

And for Bournemouth to be 2c that is really cold.  Sub zero for many 

 

BFTP

Now showing 1oC for Tuesday every little helps

[Singularity]

Talk of drifts has got me wondering, for the first time I can recall in fact, whether the models in any way factor in how wind affects snowfall.

It becomes relevant when the snow is dry and powdery - it can travel dozens of miles downflow in a brisk wind. I've experienced a moderate fall of powder snow beneath clear skies with the nearest clouds out near the horizon.

Incidentally, turbulent winds can also lift powder snow quite high into the air - but I doubt that can account for much snow transport in this country with all its obstacles sticking up out of the ground!

[stratty]

Just now, Battleground Snow said:

Can see visually here the difference compared to the 00z run... Breakdown held back for sure.

.....yep, I don't think that front will end up anywhere near the sw come Thursday in reality!

[Battleground Snow]

8 minutes ago, Phil Blake said:

I only see -10s with -12 clipping south east or are my eyes deceiving me

I wish we could have the charts @ICE COLD posts for the para, it's hard to make out but I think it is -14

[kold weather]

GFS ensembles are really struggling to get the first LP too far north, and sliding it off to the east.

This is a mixed blessing, it keeps the country in colder air for longer BUT the upstream low I've got to admit looks beefy. I suspect regardless of what the 1st low does (IMO it may well slide over the SW and into the channel) the 2nd one will come through like a steam train, and if thats the case it may be a literally leading edge snow-rain event, especially the further south you are.

[radiohead]

06Z GEFS 850 mean at 186 hours looks about 4 degrees colder than than the 0Z for most places. More positive signs.

[BLAST FROM THE PAST]

On 03/02/2021 at 07:48, BLAST FROM THE PAST said:

Well if we are talking models as they stand and not what might tweak as we get there the ECM, UKMO AND GFS 00z (certainly the runs I’m looking at) are very snowy for S and SE too.  Cold dominating and holding and going on.  There’s no “Midlands North” about those runs.

 

BFTP

And the domination of the cold leads to longevity.  Plenty of signs that an Atlantic incursion will be disrupted and forced under.  This is real deal cold coming with ‘hanging around’ snow on the ground.  The UKMO is a brilliant run, they all are tbf

 

BFTP

 

 

Edited February 4, 2021 by BLAST FROM THE PAST

[ICE COLD]

2 minutes ago, Battleground Snow said:

I wish we could have the charts @ICE COLD posts for the para, it's hard to make out but I think it is -14

Yer it is a shame the gfsp doesn’t update on that site I use for them charts . It does look between -13 and -14  tho . Brilliant runs just keep coming . 

[Phil Blake]

4 minutes ago, Battleground Snow said:

I wish we could have the charts @ICE COLD posts for the para, it's hard to make out but I think it is -14

Pretty hard on my phone but the arrow points to where the -14 is. If we can get the low out west to disrupt and head under the cold block there'd be a good chance of getting that even colder beasterly air moving towards us

[ICE COLD]

6 minutes ago, Battleground Snow said:

I wish we could have the charts @ICE COLD posts for the para, it's hard to make out but I think it is -14

Actually if you look on the normal gfs at around the T100 mark -13 850s are in east anglia

[TSNWK]

7 minutes ago, kold weather said:

GFS ensembles are really struggling to get the first LP too far north, and sliding it off to the east.

This is a mixed blessing, it keeps the country in colder air for longer BUT the upstream low I've got to admit looks beefy. I suspect regardless of what the 1st low does (IMO it may well slide over the SW and into the channel) the 2nd one will come through like a steam train, and if thats the case it may be a literally leading edge snow-rain event, especially the further south you are.

You know what. If we get 6 days of ice days and streamers as is currently model in exchange for the breakdown you describe.. it's Deal! Mr banker!

[Phil Blake]

Just now, ICE COLD said:

Actually if you look on the normal gfs at around the T100 mark -13 850s are in east anglia

I prefer these views. Much easier to see the actual values. Cheers for that

[jason6347]

1 hour ago, MJB said:

60h 

72h

84h

93h

102 h

Impressive 

 

Hi are these charts a good guide usually?

[MJB]

1 minute ago, jason6347 said:

Hi are these charts a good guide usually?

Like all automated ppn charts a pinch of salt is needed , they are off the GFS 6z ...............its a guidance for sure and helps with the set up but never ever take them as gospel 

[Nick F]

22 minutes ago, Singularity said:

Talk of drifts has got me wondering, for the first time I can recall in fact, whether the models in any way factor in how wind affects snowfall.

It becomes relevant when the snow is dry and powdery - it can travel dozens of miles downflow in a brisk wind. I've experienced a moderate fall of powder snow beneath clear skies with the nearest clouds out near the horizon.

Incidentally, turbulent winds can also lift powder snow quite high into the air - but I doubt that can account for much snow transport in this country with all its obstacles sticking up out of the ground!

Powder snow does seem to have amazing powers, not only is it prone to cause great drifts if its windy unlike snow with high water content that sticks to everything, it can find its way through the smallest cracks. Always remember the infamous 'wrong kind of snow' which I think was coined by the back then British Rail in the Feb 1991 severe cold and snowy spell. The dry powder snow infiltrated the mechanics of the electric train motors and caused issues with short-circuiting. I remember getting a train home to Kent from London on a Sunday during the onset of the Jan 1987 severe spell and remember the powder snow coming inside through the gaps between doors on the train, amazing qualities it has.

Anyway, going off topic. Easterly arctic continental flows are inherently dry at the surface, so snow falling from moister upper levels tends to have lower water content than that the moister polar maritime air that brought snow back in January via the NW. 

06z GFS op for London quite close to the average of the GEFS spread  through most of the run, quite a few colder options in there, not really any sign of a 'warm up' until late in the run - which is too far out to have any guidance. Certainly good scope to stay cold for most all of next week.

Edited February 4, 2021 by Nick F

[Battleground Snow]

9 minutes ago, Phil Blake said:

I prefer these views. Much easier to see the actual values. Cheers for that

The meteociel charts are back for UK view now on the para, we will compromise on -13 haha

[mulzy]

11 minutes ago, jason6347 said:

Hi are these charts a good guide usually?

No!

[Eagle Eye]

I hope everyone sees some snow this weekend, it seems the south west will see the least but who know, although for the first time Scotland could see the least snow over the weekend.

The snow could reach crazy depths in places Like London by the second day of Snow, I expect that the 4 or 5 day period will peak on Sunday-Monday and that a blizzard commitee should be held.

It's almost definilty going to happen hope everybody get's some Snow here's some Precipitation Charts to get your appetite up.

Xander