Model output discussion 25th Jan - The final third of winter beckons..

[Stu_London]

18z follows the normal uk winter mantra in that anything that can go wrong will go wrong.

I think given the lack of solid ensemble support it was inevitable that GFS would throw something like this particularly given the short term variables on offer.

I would still say 70% chance still of some sort of cold shot, with some snow

Perhaps 25% of something noteworthy (Noteworthy being a Feb 2009, Jan 2010 type event)

Less than 5% of something epic (Epic being Feb 1991, Jan 1987)

 

[stewfox]

47 minutes ago, The Weather Dragon said:

The pub run gives us a slap in the face - it says 'get real' - fridays synoptics not sorted yet - never mind next week - expect a further dose of grounding tomorrow 

Does appear that 'something' each time is  stopping cold weather heading further west. Seen it a few times this winter.

 

Edited February 1, 2017 by stewfox

[Guest]

NIPPY FEBRUARY 850s

Just for a bit of fun, I thought I'd have a look into the archives to pick out some charts where we have seen some pretty low 850s over the UK during February cold spells and compare these to today's ECM12z T+240 chart.

                                                                                                                                                          2017   ????                                                

                                                                                                                               

                         2009                                                          1991                                                       1986                                                       1979                                                       1963                                                        

     

                        1956                                                       1947                                                          1941                                                        1940                                                     1929          

     

                        1917                                                         1895

  

These were all events associated with continental flows with winds somewhere between south-east and north-east. There are very few examples on northerlies but one stands out - 1969:

                       1969

These are from my memories of famous cold spells - those that I witnessed (from 1956 onwards) and those that I read about. I only included examples where somewhere in the UK had 850s at or below -12. I have obviously missed a few, especially those that occured in otherwise mild winters. I did not include December or January events or Februaries with multiple cold pooling events (just the main one). The 1940s and 1960s had other Februarys which came very close. So these events have always been quite rare, even when Arctic sea ice was over 500 miles closer to the UK. Now, let's add another example this year!

Edited February 1, 2017 by Guest
Re-space charts to fit properly

[Mucka]

Cracking UKMO 144 with a hint of undercut.(or at least trough disruption)

 

GFS puts the Atlantic in overdrive which means slow burner.

 

So a game of patience but it does build a super block

 

Edited February 1, 2017 by Mucka

[SMU]

Yes - putting all those eggs in the one UKMO basket this morning !

UKMO 144 has the -24c isotherm in central europe pushing west,..

GFS good but needs more undercut....

[northwestsnow]

Well its only my opinion (and im getting so excited already)...

BUT..

UKMO is looking good at 144- its GOT to undercut at 168 SHIRLY!!!

[northwestsnow]

Just now, Steve Murr said:

Yes - putting all those eggs in the one UKMO basket this morning !

UKMO 144 has the -24c isotherm in central europe pushing west,..

GFS good but needs more undercut....

Steve if ECM looks like ukmo at 144 we are in, im sure of it.

GFS is making an absolute dogs dinner of it all, stick with the slayer...

[northwestsnow]

GEM looks an improvement on yesterdays 12z run as well...

[Mucka]

Plenty of water to pass under the bridge before an Easterly can be called if GFS ensembles anything to go by,

Anyway here is a best case/worse case comparison just to underline the uncertainty.

[northwestsnow]

Just now, Mucka said:

Plenty of water to pass under the bridge before an Easterly can be called if GFS ensembles anything to go by,

Anyway here is a best case/worse case comparison just to underline the uncertainty.

Its an utter junk model though mucka- stick with ukmo/ecm and you won't be far wrong...

[Mucka]

Just now, northwestsnow said:

Its an utter junk model though mucka- stick with ukmo/ecm and you won't be far wrong...

I can't agree with that I'm afraid NWS. All the models have their faults (ECM has repeatedly trolled coldies this winter) and have been pretty poor at times. Where there are large differences a blended solution has usually been the outcome.

What we really need is cross model consensus before having any real confidence and even then it can all go TU.

[Gowon]

15 minutes ago, northwestsnow said:

Its an utter junk model though mucka- stick with ukmo/ecm and you won't be far wrong...

it's ranked third so it's not that bad! We all know how impressive the ukmo has been but I wouldn't discount the gfs just yet. 

Edited February 1, 2017 by D.V.R

[northwestsnow]

5 minutes ago, Mucka said:

I can't agree with that I'm afraid NWS. All the models have their faults (ECM has repeatedly trolled coldies this winter) and have been pretty poor at times. Where there are large differences a blended solution has usually been the outcome.

What we really need is cross model consensus before having any real confidence and even then it can all go TU.

No probs mucka.

Ukmo will be boss here, and i will bet my bottom dollar ecm looks similar at 144 in an hours time.

I stand by my assertation Gfs is a pile of junk..

[Mucka]

1 minute ago, northwestsnow said:

No probs mucka.

Ukmo will be boss here, and i will bet my bottom dollar ecm looks similar at 144 in an hours time.

I stand by my assertation Gfs is a pile of junk..

LOL Hope you're right - even if not GFS isn't a disaster.

But, a wise man once told me, "confidence with substance is foresight, confidence without substance is blind faith." 

[The PIT]

Pretty good agreement across all models at t144 although ecmf is 24hours older.  So plenty of model watching to come.

[MR EXTREMES]

I await the ecm with extreme caution.

Gfs has back tracked.

however the ukmo is steady and the ecm really needs to be close to the ukmo hopefully they stay in sync with each other until Friday then I will be happy.

Gfs does not have the split vortex like the other models it could be that we might miss out again and Europe enjoys another blast of cold.

I'm not convinced as the Canadian lobe of vortex on the gfs just to much Atlantic energy.

[mb018538]

GFS hasn't backtracked at all...

 

its still on the colder side of average. I did warn people yesterday about taking the coldest ensemble run at face value! Still good trends there, and a fair few bone chillers. Lots to play for!!

[Mucka]

@northwestsnow ECM looking very good at 120 

Edited February 1, 2017 by Mucka

[northwestsnow]

5 minutes ago, Mucka said:

@northwestsnow ECM looking very good at 120 

Just need that azores high to DO ONE next slide mate..

[Mucka]

168 undercut would make for a snowy chart N and E I suspect.

 

That pool of very cold air to the East right on target

Edited February 1, 2017 by Mucka

[Ali1977]

Just now, Mucka said:

168 undercut would make for a snowy chart N and E I suspect.

Some very cold air on its way in, the low over SW England may help the cold blob come in on more of a SW direction from the Baltic Sea as it sinks away. 

[mountain shadow]

4 minutes ago, Mucka said:

168 undercut would make for a snowy chart N and E I suspect.

Only gold from there surely

[Jonan92]

I dont like seeing the high getting fat and inclined to Eurasia, it cuts the stream of very cold aire flow, that didn't happen in yersterday runs

[Mucka]

Now that's a boom 

 

[MR EXTREMES]

ecm brrrrr and much much better than yesterdays