Model Output Discussion - cold spell to end Autumn

[Bristawl Si]

11 minutes ago, karlos1983 said:

Hi GP, where would we find said blog please  TIA Karlos

Go to Stewart's website - centaurea weather.com

A blog on there today is "Some thoughts on the European Winter"

Edited December 1, 2017 by Bristle boy

[radiohead]

Not much support in the GEFS for such an intense storm as shown in the Op run, though a few members do blow it up too.

[MR EXTREMES]

3 minutes ago, radiohead said:

Not much support in the GEFS for such an intense storm as shown in the Op run, though a few members do blow it up too.

Looks pretty good to me 

[northwestsnow]

Actually on closer inspection UKMO looks better than GEM at 144 with the high a bit further west meaning it wont collapse as quickly

[Frank Trough]

I've got no specific evidence to back this up but I've previously noted numerous occasions  when the GFS massively overdoes the longevity and intensity of troughing just to our east. That's mostly in summer but the GFSop is almost certainly overdoing that low. 

 

[radiohead]

4 minutes ago, MR EXTREMES said:

Looks pretty good to me 

I'm referring to the intensity of the severe winter storm shown on the 12Z GFS, not the northerly. There is good support for a northerly plunge.

[Met4Cast]

2 minutes ago, Certain kind of fool said:

I've got no specific evidence to back this up but I've previously noted numerous occasions  when the GFS massively overdoes the longevity and intensity of troughing just to our east. That's mostly in summer but the GFSop is almost certainly overdoing that low. 

 

Yes agreed.

Minimal support from the GEFS on the low exploding like it does on the OP, (fortunately or unfortunately). Broadly speaking very good support for the Northerly, some ENS members more amplified than others but just about all of them have cold air moving Southwards at 162. Some deepen the low, others barely have it as a shortwave feature. 

[I remember Atlantic 252]

Pure fantasy, true meaning of 'blizzards' for western areas, maybe low levels too, no way will it happen, Staffordshire could be a snowfest

[Timmytour]

Just now, Danny* said:

Yes agreed.

Minimal support from the GEFS on the low exploding like it does on the OP, (fortunately or unfortunately). Broadly speaking very good support for the Northerly, some ENS members more amplified than others but just about all of them have cold air moving Southwards at 162. Some deepen the low, others barely have it as a shortwave feature. 

I think Norfolk will be just on the other side of a Spring Tide when GFS brings that low down.....  exciting stuff but worrying as well

[northwestsnow]

That UKMO 144 looks an absolute beauty to me- the more i look at it the more i'm hoping EC looks like it!!

[nick sussex]

The overblown low is a typical GFS bias.

It did the same thing a few weeks back, if we remember the GFS and UKMO were more interested in developing a shortwave to the sw. The ECM didn't want to know, eventually we settled on a weak low which ran ene.

NOAA have often commented on this bias and so the odds of that low verifying are very small.

 

 

 

[Steady Easterly]

I think GFS is over intesifying the low, and historically these lows nearly always track a bit further South than shown on the last few runs, indeed its further South on this run compared to the 06z.

[Met4Cast]

1 minute ago, nick sussex said:

The overblown low is a typical GFS bias.

It did the same thing a few weeks back, if we remember the GFS and UKMO were more interested in developing a shortwave to the sw. The ECM didn't want to know, eventually we settled on a weak low which ran ene.

NOAA have often commented on this bias and so the odds of that low verifying are very small.

 

 

 

If they know about the bias, can't they just.. fix it?

[karlos1983]

How’s that for agreement 

[Frosty.]

1 hour ago, Frosty. said:

Yes the Ukmo 12z T+144 is a definite Boom chart for coldies, the alignment is good for a stonking  Arctic blast!..awesome stuff.

This chart should be framed and hung on a wall, it's that beautiful..been a while since I've thought that about a ukmo chart...this one makes me feel like dancing!!..hope the 00z tomorrow is as good

[northwestsnow]

1 minute ago, karlos1983 said:

How’s that for agreement 

Mild outlier 

OK OK not an outlier but colder options on the table-

I'm not watching the EC come out - i fear for the laptop...

[SMU]

56 minutes ago, booferking said:

But would the percentage not be a bit more as the boundary between warm and cold air is very sharp.

YEah possibly a bit higher- However its whether the low comes in shallower or splits into a couple of smaller systems is the key- rapid devlopment is on the cards though..

[Guest]

37 minutes ago, Nick F said:

Wow at the 12z GFS, blizzard/snow storm of the century for northern and western parts of UK next Friday into Saturday!

Caveat that GFS tends to overblow depressions at that range, but the fact that it's been showing for a few runs or more now, worth keeping an eye on.

The slow-movement of the deep low over the N Sea very unusual and appears to be tied in with the stationary long wave trough over Europe and its removal from the strong NLy jet further west meaning it doesn't have the impetus to move quickly on like normal depressions that move west to east or southwest to northeast.

Alarming charts!

 

POTENTIALLY SERIOUS NORTH SEA STORM SURGE  

I do not wish to be at all alarmist about this but Spring High tides are forecast for next week. They will peak on Dec 6th but will not be far below those levels on Dec 8th at the very time that the deep LP is predicted to move out into the North Sea. It's too early for environment flood warnings which start from Day 5 and updated daily thereafter. The Government site for those is: https://flood-warning-information.service.gov.uk/warnings  Here are the tide tables for Dover - this does not seem to have a copy facility but here's the link:   http://cspf.co.uk/tide-tables  and here's the link to the Spring and Neap tide chart (on the same freeview website): http://cspf.co.uk/tide-chart   Remember these are just tide height values under normal weather conditions. If the LP is anywhere as near as intense that the GFS predict then this would lift the sea surface by several feet at least. Even with the UKMO and GEM 12z charts (which I posted on page 78) showing less intense central pressure, the strong straight northerlies will probably produce a substantial tidal surge all the way down the east coast. So if this verifies, it could be a very unfortunate triple whammy. This is definitely one to keep a careful eye on. I shall be producing my next long report over this weekend and I'll include a brief update on any flood warnings.

 

[SMU]

Look at the controls track-

[Frosty.]

So..20 minutes to go until the biggest ecm since..err..the 00z!

If it's like the ukmo 12z at day 6 we would be looking at the best Northerly for a good few years and even if it doesnt, I think there is some exciting weather on the way after the benign milder blip.

[Glacier Point]

54 minutes ago, karlos1983 said:

Hi GP, where would we find said blog please  TIA Karlos

Here you go..

http://centaureaweather.com/weather-news/some-thoughts-on-the-european-winter/

Standard La Nina climatology may not apply here.

[Met4Cast]

3 minutes ago, Glacier Point said:

Here you go..

http://centaureaweather.com/weather-news/some-thoughts-on-the-european-winter/

Standard La Nina climatology may not apply here.

Great blog and read GP! I'm just going to go ahead and quote this part here

Quote

Whether the UK is able to tap into this cold is an issue, although the broad-scale signal at a European scale would tend to suggest an elevated risk of the coldest winter in the last five years is beckoning.

 

Edited December 1, 2017 by Danny*

[Sky Full]

The four main models show some similarities at +144 - especially the Atlantic ridge rising teasingly towards Greenland and the low 850s dangling ever closer to the NW......   However, to my uneducated eyes there are sufficient differences in the way the northerly is developing not to place any firm bets on the conditions to follow, especially that GFS storm depicted off the east coast.  If this is still showing at +72 or even +96 then we might have to start believing it, but until then I am more interested in the potential for some really cold weather to reach even these snow starved western parts...

ECM         

UKMO      

GFS         

GEM.     . 

[Derecho]

No unwelcome surprises from the ECM so far

Edited December 1, 2017 by Quicksilver1989

[karlos1983]

UKMO and ecm pretty similar at +96