Steve is the ultimate, "Reverse Psychologist", WI..

Sun/Mon onwards next week open to further upgrades...

Me ? Never ! 

I should have called curtains on this 'winter' after the early January failed easterly debacle 3 weeks back. 

Sun/Mon. Yes a new rainbow to chase. No doubt that rainbow will disappear as soon as those clouds move in from the west to blot out that increasingly strong late winter sunshine.

ECM will no doubt come out with a decent easterly looking outlook. Don't fall for it. Its a trap. 

See you back here in March lads. I'm in Spring mode now. 

 

Me ? Never ! 

I should have called curtains on this 'winter' after the early January failed easterly debacle 3 weeks back. 

Sun/Mon. Yes a new rainbow to chase. No doubt that rainbow will disappear as soon as those clouds move in from the west to blot out that increasingly strong late winter sunshine.

ECM will no doubt come out with a decent easterly looking outlook. Don't fall for it. Its a trap. 

See you back here in March lads. I'm in Spring mode now. 

i have a feelng spring will be a long time coming this year with lots of snow around even into april so see you in may steve.

Looking at the T500s on the NHem makes this a bit easier to understand.

You could almost argue it is the polar vortex. The reason the -10C isotherm is surviving is due to the insane depth of the cold which extends all the way into the stratosphere.

I did wonder; seeing a -10 850 patch reach the UK from the NW is very uncommon; for it to arc around the top of the high and reach S England (the first wave of this in the 12z op) is not something I've seen before. Then a second hit at -10s, from a westerly, incredible. But then, those 500s surely must have to be taken with reserve- unless it is an Arctic leak-in as a result of jet disruption or PV fragmentation.

I did wonder; seeing a -10 850 patch reach the UK from the NW is very uncommon; for it to arc around the top of the high and reach S England (the first wave of this in the 12z op) is not something I've seen before.

There's actually a second pulse a few days later which makes it to Kent. I guess that explains the zonal look to the GEFS at the moment - lots of sine waves in evidence, but oscillating around -3C or so down here rather than the usual +2 or so. A few of them briefly touch -10C at the bottom of the sine wave, suggesting the operational isn't alone in propelling remarkably cold air SE'wards.

FWIW, the first pulse of -10s from the NW results in highs of 3C under clear blue skies according to the GFS - interesting to experience, I guess, but those same -10s from the east instead would have resulted in so much more.

 

If by ‘South’ you mean the coastal counties of England then you may have a point. 

Depending on context ‘South’ could mean anywhere south of the Midlands and then your comment would be highly inaccurate.

Here, for example, we’ve had two substantial snowfalls; one ‘disruptive’ for a day.  We’ve had countless overnight frosts as well.  

Plus, there’s a third of winter left and the models aren’t reliable more than a few days out.

I'm not sure how this relates to my comments about the modeling of Continental harsh cold! Well obviously I meant south of the M4 corridor because we all know there was a bit of snow north of there. But that has nothing to do with my comment regarding Continental serious cold being modeled for here and not happening in previous years. At least there has been no promise of that.It seems to me that some cold fans set their sights realistically low these days or are too young to know what a harsh winter spell is! One frost here in January, scraping in for an hour at -0.6C doesn't constitute a cold January to me!

 

 

 

Cosmic

After many false dawns I really can’t be arsed chasing another phantom snow event which will probably result in an hour or two of sleet followed by a bit of light drizzle. Next week still looks dry and cold for many so at least we’ll see some frosty nights.

 

There's actually a second pulse a few days later which makes it to Kent. I guess that explains the zonal look to the GEFS at the moment - lots of sine waves in evidence, but oscillating around -3C or so down here rather than the usual +2 or so. A few of them briefly touch -10C at the bottom of the sine wave, suggesting the operational isn't alone in propelling remarkably cold air SE'wards.

FWIW, the first pulse of -10s from the NW results in highs of 3C under clear blue skies according to the GFS - interesting to experience, I guess, but those same -10s from the east instead would have resulted in so much more.

I'm not sure its game over yet Darren.  I think its best to wait at least 24 hours on this one.  

Expect plenty of scatter in FI on the ECM ens.

And here's what JMA thinks of things at T144 and 168!
http://www.meteociel.fr/modeles/jma/runs/2018013012/J144-7.GIF?30-12
http://www.meteociel.fr/modeles/jma/runs/2018013012/J168-7.GIF?30-12

Yes, a lot of bolt shooting has happened this evening. More runs needed.

12z gives a London snow-row total of 104; I think it topped 120 once this season- but, boy, what a contrast this year, forecast-wise even, compared to the previous 4. The better winter continues.

12z gives a London snow-row total of 104; I think it topped 120 once this season- but, boy, what a contrast this year, forecast-wise even, compared to the previous 4. The better winter continues.

I've certainly seen more snow falling this winter than in the last two or three, but it hasn't resulted in anything more than a dusting at home, and a temporary couple of cm on the top of the Surrey Hills earlier in the month.

It also seems that the variability both between models and between runs has been at an all-time high, or maybe I'm just looking at more different models these days. 

I've added in 5 and 10 day temp anomaly charts. They compare the GFS op to the 1981 - 2010 reanalysis data from NCEP. They are logically correct but I have some reservations. Hopefully they'll be of some use, the direct links are: 

5 day temp anomaly 1981 - 2010

10 day temp anomaly 1981 - 2010

 

I've certainly seen more snow falling this winter than in the last two or three, but it hasn't resulted in anything more than a dusting at home, and a temporary couple of cm on the top of the Surrey Hills earlier in the month.

 

It also seems that the variability both between models and between runs has been at an all-time high, or maybe I'm just looking at more different models these days. 

Maybe, but I've felt that too- although a member for <3 years, a watcher for longer. I think maybe the models deal with less frequent weather patterns less well than the frequent. Stands to reason- scientifically, greater sample size correlates with greater confidence levels. The odd & often conflicting signals this season have meant that even the most knowledgeable on TWO seem perplexed at times.

As I suspected, a  large variation in the 2m temperatures on the SW Holland ensembles from day 5, which then widens to make pretty much anything possible from day 8: 

https://www.weerplaza.nl/15daagseverwachting/?type=eps_pluim&element=&r=zuidwest

Cooling then warming trend discernible though.  But a different picture will be painted again in 12 hrs time.

Is that the mean temperature anomaly or the max temperature anomaly, Brian?

Mean.