Trust the pub run

Yes, quite interesting but, importantly another variation on a theme of high latitude height rises.

 

If you really think it's 'one or the other' then I don't think you understand the complexities.

Can you just describe for me a type of winter which would not be evidence of climate change then. A cold one evidently is, because "scientists agree." A mild one is - everyone agrees. 

Good cross model agreement for blocking right over the Arctic on most if not all models BY +240z: - Indicative of a -AO and NAO and weakened zonal flow. Just a shame this doesn't look like bringing in much in the way of cold air...!?

18z Operational:

ECM:

GEM:

 

Can you just describe for me a type of winter which would not be evidence of climate change then. A cold one evidently is, because "scientists agree." A mild one is - everyone agrees. 

A bang average one? 

Its worth noting the GFS 10 Day mean on the 18z

 The model is starting to get to grips with the pressure rises over the pole.

Im not sure whats more notable > the GH pressure increases or the anomalous cold appearing over the area of PV dropping south...

 

Can you just describe for me a type of winter which would not be evidence of climate change then. A cold one evidently is, because "scientists agree." A mild one is - everyone agrees. 

I don't think this thread is the right place for this discussion but the only thing we can say is that there's an unarguable warming trend, most pronounced in northern latitudes and clearly present in the CET. The next clear message is that adding energy and shifting the energy balance in our complex atmospheric system should be expected to have, and is having, consequences.  Third, a warming Arctic means a reduced volume of cold air, and that air is less cold (as evidenced in that research linked to by Steve Murr): then warming oceans means more modification of those cold air masses as they advect south. Finally, there's evidence of the high pressure belt to our south encroaching slightly further north (also a prediction of the climate models).

None of this means cold spells won't happen; it means they become less severe and less common. I think, again, that the records support this.

 

Thanks!

I will add my thanks as well. It was an interesting read and echoed some of my thoughts.

Over the years here a number of people have reminisced about the times when the weather sprung surprises, simply because the forecasters had so much less data and we had none at all to scrutinise.  I remember going to bed when the forecast was for overnight rain and waking to heavy snow; and the opposite. 

 

If you really think it's 'one or the other' then I don't think you understand the complexities.

Forgive but this is kind of answer I would expect some religious nut or politician to give. 

 

Forgive but this is kind of answer I would expect some religious nut or politician to give. 

Read GtW's other [excellent] post #901, where he goes into more detail.

Then take on board his suggestion in the opening sentence. 

Everyone was banging on pre 2009 about modern era winters, and that we would never see a proper cold winter spell like those of the earlier decades. Then comes along the winter of 08/09 a cold winter that ended with some of the most significant snow seen in the southeast for many a year (decades for some). The winter after 09/10 saw a severe one, and one of the coldest spells seen since the 80's. Then the December of 10/11 season was the coldest on record! Since those three winters there have been a couple of other notable cold spells 2012, and also the extreme cold of the late winter early spring Beast in 2018 that saw widespread day time highs sub -3C in March in the south. The sea froze at the Isle of White. 

People talk of the memorable cold of past decades but they seem to forget that in between these cold spells there was plenty of mild, wet, stormy. and boring weather which is much that is more typical of our climate.

Taking away the winter of 62/63 as it was a truly exceptional once a every few centuries one. The remaining natable nationwide cold or snowy winters of the last century can probably be counted 2 hands.

 

Forgive but this is kind of answer I would expect some religious nut or politician to give. 

Then perhaps you’re of those that doesn’t understand.

I have posted a more detailed comment; did you get that far before posting your one-liner? If not, let me know what you rethink after you’ve read it.

Swerving back to the NWP and a quick skeg through the 18Z GEFS is entertaining. Some absolute belters in the bag of pick and mix this evening.

The ECM 12z ensemble set for London 2m temperatures is also quite encouraging if you’re looking for support for a cold outlook as we approach Christmas. One cluster offers average to slight cool and two others go into cold and very cold territory by the end.

Swerving back to the NWP and a quick skeg through the 18Z GEFS is entertaining. Some absolute belters in the bag of pick and mix this evening.

If the low on the ECM at day 5 was 400 miles south then i would imagine folk north of the midlands would be talking of a snow event. 

An adjustment of a 400 miles over 5 days isn't impossible.

 

If the low on the ECM at day 5 was 400 miles south then i would imagine folk north of the midlands would be talking of a snow event. 

An adjustment of a 400 miles over 5 days isn't impossible.

Agreed. But in which direction?

😉

🤣

Swerving back to the NWP and a quick skeg through the 18Z GEFS is entertaining. Some absolute belters in the bag of pick and mix this evening.

Been looking through the GFS ensembles over the last 3 or 4 days and there is a definite trend towards colder evolutions as we head towards/beyond Christmas. Looking at tonight's 18z there are certainly some very cold runs in there notably 3, 6, 11, 12, 16, 18, 20, 28 and with some others almost there, or in between. Still a lot of runs there with an Azores/Euro influenced pattern and strong Atlantic influence though

I'd say momentum is increasing towards some sort of colder spell around/beyond Christmas and the Met's medium/longer term forecasts seem to back that up. As ever though it looks very finely balanced and the level of confidence is questionable. 

Certainly a more interesting outlook than recent Decembers.  

 

Agreed. But in which direction?

😉

🤣

? I already said south.

Merry Christmas

It would be good to see a real White Christmas after a personal 80 years - white Boxing Days or a light cover on Christmas Day are the best I can remember.

But http://www.wxmaps.org/pix/temp4 still has the Siberian cold uncommitted to W Europe, and hanging around over Russia, while Europe's western fringes stay under Atlantic influence on the accompanying pptn chart - dampening in more senses than one.

GFS has a series of troughs moving across the UK from the Atlantic, and filling as they go,  notably Sun 13th, Thu 17th and Sun 20th culminating in a deep LP in the N Sea 965mb on Xmas Day, looking cold enough for snow on hills.

GEFS is very simple - temps near seasonal norm for next fortnight and rain on and off throughout. A few, repeat few, very cold outliers at the end.

ECM generally agrees with GFS  though the trough on Sun 20th is somewhat deeper, more of a full-blown LP