Model output discussion - mid-winter

[Devonshire]

1 hour ago, Bring Back1962-63 said:

This post will be rather shorter than my normal meanderings

Thanks for keeping it short and to the point - although you classify yourself as a 'learner', your posts always contain some interesting angles. I appreciate brevity that does not compromise by missing anything of importance out. I look forward to visiting the teleconnections thread.

[Matthew Gill]

34 minutes ago, Ice Day said:

And the obligatory charts showing the 'potential' SSW.  Starting at 204

Peaking with this at 348

It's not going away!

A real novice here. Am I right in my assumption that a warming in the strat means more pressure on the vortex which means more chance of cold blocking? Or have I got this totally wrong? 

[karlos1983]

4 minutes ago, Matthew Gill said:

A real novice here. Am I right in my assumption that a warming in the strat means more pressure on the vortex which means more chance of cold blocking? Or have I got this totally wrong? 

Probably worth heading to the Strat thread Matthew, especially with the current warming predicted. Interesting times

[sub zero]

8 minutes ago, Matthew Gill said:

A real novice here. Am I right in my assumption that a warming in the strat means more pressure on the vortex which means more chance of cold blocking? Or have I got this totally wrong? 

Basically yes..

read the first post on page one of the strat thread, it's a good read and will hopefully enlighten ..

[Man With Beard]

EC clusters did not eliminate the previous op run clusters for D8-D10 (less cold), so beware jumping to conclusions on the upcoming northerly.

[feb1991blizzard]

3 minutes ago, Man With Beard said:

EC clusters did not eliminate the previous op run clusters for D8-D10 (less cold), so beware jumping to conclusions on the upcoming northerly.

And after that the warm cluster is bigger than the cold cluster in the extended period, I was disappointed with the London graph not only in the extended period but in the N'werly, for no member at all to have an air frost by next Thursday is odd, you would think with a clean NW flow, there would be some clear skies in London at some point overnight next week.

[BlackburnChris]

1 minute ago, feb1991blizzard said:

And after that the warm cluster is bigger than the cold cluster in the extended period, I was disappointed with the London graph not only in the extended period but in the N'werly, for no member at all to have an air frost by next Thursday is odd, you would think with a clean NW flow, there would be some clear skies in London at some point overnight next week.

maybe a sign of how much precipitation is expected .

[feb1991blizzard]

1 minute ago, BlackburnChris said:

maybe a sign of how much precipitation is expected .

Little PPN but does look like a cloud issue.

[BlackburnChris]

1 minute ago, feb1991blizzard said:

Little PPN but does look like a cloud issue.

well tomorrow we will be into 72 hours so hopefully be able to start to firm up on early next week

[Duane S.]

Crackingly interesting charts on the horizon for next week.

Too much focus as usual on the uppers though. Those thicknesses are the real eye openers.

The snow could end up only being half of the story as well. There is likely going to be some interesting embedded features as the week wears on. Squalls, large hail, CGs. Not sure about a polar low cropping up though, too much of a PM element as opposed to Arctic.

[BlackburnChris]

Really cant see whats marginal about these charts in January ....

 

[The Enforcer]

1 hour ago, Ice Day said:

And the obligatory charts showing the 'potential' SSW.  Starting at 204

Peaking with this at 348

It's not going away!

Omnipresent at T+384. However, Chiono has been right about it showing on 20th to date. Does it have to look like it does at T+384 to be effective or is the T+204 version sufficient to have an impact?

[mulzy]

As expected from the ECM London temperature ensembles, nothing much to look forward to from the westerly 'blast'.  As I have been pointing out the interest comes in the day 7-10 period for most of lowland Southern Britain.

[feb1991blizzard]

2 minutes ago, The Enforcer said:

Omnipresent at T+384. However, Chiono has been right about it showing on 20th to date. Does it have to look like it does at T+384 to be effective or is the T+204 version sufficient to have an impact?

To have the desired effect of completely destroying the vortex for the rest of winter, it needs to go even further than 384, we are hoping that the wave 1 will displace it but then be quickly followed up by wave 2 to split it.

[MKN]

1 hour ago, feb1991blizzard said:

Here is the snow depth chart in centimetres so although GFS overdoes these - suggests not without interest although Exmoor / Dartmoor favoured more for significant accumulations obviously.

In showery set ups i would actually say the gfs often underplays these due to one place getting 15cms and 10mile down the road getting next to nothing therefor these often just show the entire sort of area getting around a couple of cms instead. 

[Weathizard]

14 minutes ago, mulzy said:

As expected from the ECM London temperature ensembles, nothing much to look forward to from the westerly 'blast'.  As I have been pointing out the interest comes in the day 7-10 period for most of lowland Southern Britain.

Yep, obviously certain members are getting over excited due to IMBYism which you can totally understand.. shame for us southerners, but as I said earlier -5 will simply not cut it for us from that direction.

 

Need to keep the building blocks for some proper stuff coming into a reliable, been fairly consistent that some kind of ridge will attempt to go north at day 6+ just depends if we get lucky, otherwise the fears of another snowless winter will rear again.

 

Edited January 12, 2018 by Weathizard

[JBMWeatherForever]

I think the only IMBYism is from those who are still managing to be so negative when there is such a wintery looking outlook for next week for at least most of the British Isles, and perhaps eventually for all of the British Isles. 

[Mucka]

GFS 00z is yet another upgrade on the cold zonal flow, especially as it gets into full swing, but perhaps handling of the trough is a little suspect.

00z/18z comparison 850hPa

UKMO 00z/GFS 00z comparison 144

 

Edited January 12, 2018 by Mucka

[Cheshire Freeze]

25 minutes ago, Mucka said:

GFS 00z is yet another upgrade on the cold zonal flow, especially as it gets into full swing, but perhaps handling of the trough is a little suspect.

00z/18z comparison 850hPa

UKMO 00z/GFS 00z comparison 144

 

Well there's one thing...the end of the GFS 0z is a belter

Better late than never 

[Mucka]

GFS 00z continues the fun throughout FI.

Battleground Britain.

Somewhere, probably many places would get a pasting if this run came off. we can dream.

And just for good measure it ends with the Easterly that has been teased for so long.

I dare say many NW members would sell kidney for this run to come off (please read the fine print before you do)

 

 

[reef]

The GFS 00z run is probably the snowiest run for quite some time. We go from cold zonal westerly, to northerly followed by a potent easterly right at the end of FI. Just about everywhere would be hit at some point or other:

Western areas:

North and east:

Potentially everywhere:

One can only hope it comes to fruition.

[Daniel*]

Things are ticking along very nicely having just viewed GFS 00z it really is wintry throughout from Tuesday - the cold doesn’t ease in fact it intensifies and a significant cold easterly spell sets in. It has it all.

[Mucka]

GFS ensembles are the coldest set yet, certainly when it comes to prolonging the cold from the NE/E.

Each set has been rock solid on a warm up from the 21st as more typical zonal conditions took over but this set has bucked that trend.

I mentioned last night GFS ensembles were sniffing the air as far as blocking prospect go later in January and now they seem to want to take a taste - and the taste is Winter!

GFS 00z central England and below last 06z set for comparison.

Note any warm up now put back 24hrs to 22nd a clear split developing thereafter with a nice cluster of cold runs.

Are they barking up the wrong tree and will future runs revert or will the trend continue?

[Cheshire Freeze]

5 minutes ago, Mucka said:

GFS ensembles are the coldest set yet, certainly when it comes to prolonging the cold from the NE/E.

Each set has been rock solid on a warm up from the 21st as more typical zonal conditions took over but this set has bucked that trend.

I mentioned last night GFS ensembles were sniffing the air as far as blocking prospect go later in January and now they seem to want to take a taste - and the taste is Winter!

GFS 00z central England and below last 06z set for comparison.

Note any warm up now put back 24hrs to 22nd a clear split developing thereafter with a nice cluster of cold runs.

Are they barking up the wrong tree and will future runs revert or will the trend continue?

Note at day 10 we've got the troughing pretty much where we want it...

Over Europe

[Daniel*]

Wow

...dreamy stuff in the ENS in cuckoo land best of all the upgrades keep coming not only in short-medium term. Ian Pennell’s winter forecast I think was a very good one, not that this is set in stone but he did talk about a significant cold spell towards late January.  

 

Edited January 12, 2018 by Daniel*