Stravaiger

I honestly don't like this set up one bit. It's got disappointment written all over it given the strength of the jet going over the top of the high. I'd take a period of proper, stormy, coolish zonality over this any day. Kick the jet and the Azores high well to the south, with a raging PV moving east over time to be just to our north. It feels like we can never remove high heights from being close to the south of the UK these days and with that, we kill the prospects for even average uppers unless the spectacularly unlikely happens. This kind of garbage just eats up the precious weeks of low solar heating.

Nick - do you find energy disrupts south less readily nowadays than it used to? Always seems torturous to get the PFJ to dive south of England, when it must have done all the time in winters past.

Well what a spell of model watching this has been...I don't about you guys but when the stakes are this high and the uncertainty is this great, I find the model watching very compelling. There are still massive differences between the Big 3's 12Z runs regarding the shape, structure and centre of the lows around the UK at T+72, weirdly agreement is almost better at T+96, but even then notable discrepancies persist. The point is we still don't know how things are going to pan out later on this week and, I'm afraid, trying to pin one's hat on anything at the moment, whether that's ensemble trends or operational run's consistency, is likely to give an unjustified sense of confidence, esp. for the period after Christmas. The good news is that cold weather still very much has a seat at the table. At least in the North. The bad news is that things are far from nailed on. You know the drill...more runs needed and let's pray for the result us coldies deserve.

That’s just it - go back to the archives and show me any year pre-2019 where the UK gets >20C temps in Feb. As I said, I totally understand SSW’s deliver anomalous warmth and cold, but the degree of anomalous warmth is what is increasing. Hence we set a Feb record in 2019, and if these runs had verified could have set another one this year. In a warming world, post-SSW synoptics now have a greater chance of delivering >20C temps to the UK in winter than they did before. That’s all I’m saying.

I’m with Don...completely understand the variability we can be prone to at this time of year, but the parameters have shifted in favour of warmth. You would never expect to get temperatures above 22C in the UK in February, it wouldn’t really have been considered climatically possible 50 years ago. It relies on exceptional, anomalous warmth being there to our south for unusual post-SSW Synoptics to draw north.

Thanks MIA - informative as always! I think you mean Franz Josef Land, though, Jan Mayen hasn’t had sea ice in a good long while...at least as far as I’m aware

BFTV - do you know what the lowest, minimum-distance has been? Are we approaching some kind of record...? Presumably we are for November, but I wondered if maybe for any time of the year. The climate of Svalbard is irrevocably changed from what it was even 50 years ago.

Yup - and the complete lack of a refreeze in the Barents is worrying, too. With the jet running to the north of European heights for the foreseeable, allowing bouts of mild air into the High Arctic at times, I can’t see any sustained winter weather making inroads into these parts any time soon...

Super interesting @Daniel* - thanks for sharing! I'm not sure albedo tells the whole story, though...think the discrepancy you highlight is mainly due to heat being emitted from the relatively warm open water north of Siberia, which is stopping air temperatures falling really low. There is almost no sunlight that far north by this time of year, so albedo is less important than in, say, spring-time, when there is a lot of incoming solar radiation to reflect. Two important factors are the relative specific heat capacities of land and water, which allows land-masses to cool down far faster than oceans at this time of year, and the effectiveness of snow as an emitter of longwave radiation. These two effects combine over the snow-covered parts of Russia and North America. The Arctic sea ice, for its part, acts like a lid on the warm sea water below it, preventing the release of heat from the Arctic Ocean into the atmosphere. Much of the sea-ice will also have snow cover, too, which will allow it to radiate heat effectively into the polar night when conditions are still and cloudless, helping lower temperatures further.

@Mucka - with respect, I don't think you're framing this correctly. Everything you say about CO2 being a trace gas is true. As is the fact that the Earth (and life on it) will cope just fine over geological timescales even if humans push the planet's average temperatures into a warmer stable-state. That said, thinking about this issue from a geological perspective ignores the crux of the issue, which is the suffering - human and non-human - that it will cause in the coming decades and centuries. Rather than worrying about whether it's important that you "do your bit" and buy an electric car, think about the people and animals who are already suffering as a result of the *impacts* of the increase of this trace gas, CO2, in the atmosphere, which has occurred rapidly since the industrial revolution. These impacts are here already, clear as day. Sea ice is decreasing in extent and thickness. Not great if you're someone who relies on it for travel, hunting, food or security. Not great for the knock-on effects it will have on our climate. Sea-levels are rising, with many Pacific Islanders and people in southern Asia already suffering as a consequence. It is certain that some Pacific Island nations are going to become uninhabitable this century. Imagine if that was your home disappearing beneath the waves. Or perhaps, consider if you owned a ski resort or a winter-sports business. Would you be thinking so abstractly and calmly about Earth's long term climate trends or would it be causing you stress and suffering in the here and now? What if Australia's climate-linked bushfires had just ripped through your community?? The impacts of climate change and the human suffering they are causing and will continue to cause cannot be disregarded. If the climate changes too rapidly, agricultural businesses will be destroyed, fisheries will collapse, timber-producing forests will burn, etc., etc., all of which will cause immediate economic harm to those affected. I agree that we desperately need China and India to join this fight, along with every other nation and corporation on the planet. But even if those entities are slow on the uptake we have to continue trying to reduce our greenhouse footprint as much as possible, taking into account the complexities re economic trade-offs that you rightly raise.

Latest blog from the guys at the NSIDC: Arctic Sea Ice News and Analysis | Sea ice data updated daily with one-day lag NSIDC.ORG Even they are talking about ozone in relation to Arctic warming this month!

The excellent NSIDC blog has just updated with this month’s post now live. Contains the normal summary and a good, concise review of the 2010s from a sea ice point of view: Arctic Sea Ice News and Analysis | Sea ice data updated daily with one-day lag NSIDC.ORG

I've been thinking about this too... There is a theory (and evidence) that links anthropogenic global warming with stratospheric cooling. The latter influences the strength and speed of the tropospheric polar vortex (tPV), keeping it colder and tighter, with faster winds circulating around it (the polar night jet), which protect it from destabilising interactions with other parts of the troposphere. As the PV increases in strength and the boundary between polar and sub-tropical air (the polar front jet) is sucked ever further north, the sub-tropical (semi-permanent) high pressure systems ridge further north too, e.g. into Europe in winter, when normally this would be a summer phenomenon. Coupled with this is the fact that there is just less cold air to go around, due to the rapid and ongoing warming of the northern hemisphere's high latitudes, so it is no longer possible for everywhere to have an average winter, temperature wise. Somewhere will always be anomalously mild. The bad news is that, as the greenhouse gas content of the troposphere continues to increase, less of the infra-red that Earth emits will make it to the stratosphere and warm that portion of the atmosphere. So we can expect a cold stratosphere and a tightly-wound, powerful tPV to be an even more persistent feature in the coming decades...unless something else occurs that overrides this increased GHG - stratosphere interaction This is obviously a very simplified explanation. More info and links can be found here for those that are interested: Global Warming Causes Stratospheric Cooling | Weather Underground WWW.WUNDERGROUND.COM Read in-depth about causes of global warming and climate changes by top meteorologist Dr. Jeff Masters at Weather Underground.

If I’m honest, I’d take the GFS over the ECM at day 10. The former at least has us in a W’ly flow with temperatures close to average in the north and snowfalls piling into Scotland’s mountains at times... ECM on the other hand sets us up for a protracted battle between a MLB and Atlantic troughing, which will likely result in nowt but an extended spell of long-draw southerly winds. Bring on rampant zonality, I say...at least we’ll get some Pm air in the flow from time to time and can hope that the jet works its way south later on in the month, giving us a better ratio of Pm:Tm airmasses.

Latest NSIDC blog out for November. The month had the second lowest ice extent on record, though according to the NSIDC's passive microwave satellite data extent is now up to the third lowest for the time of year, ahead of 2016 & 2006 (I'll be watching 2026 with interest...!). Arctic Sea Ice News and Analysis | Sea ice data updated daily with one-day lag NSIDC.ORG

Thanks for the continued updates MIA. Great to see the Kara nearly full...hopefully the natural shield of NZ will protect the ice from any warm Atlantic incursions! A relief to see the Chucki making sustained big gains at last, too. Re MOSAIC - were they not expecting to have to heat the ship with their diesel engines? Slightly distressing to think they're burning so many tonnes of fossil fuels each day in the High Arctic, and contaminating the ice with soot, etc. I'm also amazed they didn't think the engine's outputs would contaminate their experiments...that seems a massive oversight. Or am I missing something? Very interesting to monitor their drifting in any case and see where they end up!

Net positive snow cover anomaly in the NH at the moment. Expect the reds in N and E Europe to grow in the next 7 - 10 days though, sadly, as warmer air moves north into this part of the world. Hopefully the Kara will finish freezing before this happens...seems to be icing over mighty quick right now. Interesting spell of weather coming up, with some signals for the PV to migrate over to the E. Siberian side of the pole in a week or so. Still seems quite a fluid situation so will be hard to predict where we'll be, in terms of a hemispheric pattern, as we approach December and winter proper...

Thanks for another update MIA, it is certainly nice to see the Kara sea freezing over so quickly this year, and indeed the whole NE Atlantic area rallying somewhat. I just find it so sad that in these days of global heating, the Arctic's cold seems to have to pick its battles. If one region sees average or below average temperatures it is now always offset by anomalous/extreme warmth elsewhere. The days of getting sustained below average temperatures on both sides of the pole seem to be behind us. Only 30 years ago, the ice north of Barrow Point, Alaska, would some summers barely recede from the coast at all. Now, in mid-November, two months after the minimum there are still hundreds of miles of open water left in the Beaufort sea. I particularly worry about the Chucki sea, though. This year is really bad, even in comparison to the previous decade, which itself has been consistently below par (see the image from November 2011 below). It feels like the early melting and commensurate rise in water temperatures is starting to take its toll in this part of the Arctic. Refreeze is later, spring thicknesses are way down and, combined with that, weather patterns seem less and less conducive to extended periods of extreme cold taking hold. Hopefully, the cold air that is expected to move into the Chucki in the next few days will help the dwindling ice cover to rapidly expand, but I just worry that we're very close to, if not already past, a tipping point in this part of the world. Selfishly, its been wonderful to see the low temps in our neck of the woods. Scandinavia, in particular, has had an impressive cold spell of late. Now, it seems that the focus of the Arctic's fury is shifting to North America for a time. Hopefully, it will revisit Europe again before too long!

Really enjoying this thread - thanks to all who keep it going so reliably! Those who haven't seen this website before, but are interested in this topic, will enjoy this: http://nsidc.org/arcticseaicenews/ Its a blog, updated every month or so, about conditions in the far north. It provides a good overview of how low the extent is at the moment, relative to historic averages. But it also notes the increased ice and cold around Svalbard, which has been lacking in recent years. Indeed, it is one of the few times in the last ten years that I've seen the Norwegian Met Service record a 30-day run of temperatures in Svalbard that aren't above average. Check out this statistics page to see how drastically warm the last twelve months have been in that part of the Barents, relative to the long-term 'normal': https://www.yr.no/place/Norway/Svalbard/Longyearbyen/statistics.html Cheers all!

With signs of a pronounced Arctic high now appearing consistently around the 10 day mark, pushing the polar vortex lobes further apart, I started to wonder how unusual this winter has been in terms of a lack of polar vortex integrity...? Realise this is slightly off topic (sorry mods) but I’d be particularly interested to hear from some of the experienced guys and gals on here about this...when was the last time we had an early winter period with such a weak, uncohesive vortex? Maybe it happens all the time and I’m just too new to the game to have been aware...

How unusual is it to see the polar vortex this disrupted / amassing over the Russian Arctic at this time of year? Normally its setting up somewhere near Greenland and Baffin Island... Does this link to @Steve Murr's insights about the increasing lack of ice in the Barents/Kara seas?? Be interesting to see if it has any ramifications for the U.K. in terms of northern blocking etc. as we head into winter.

I think that there is a difference between shifting the blocking and sinking it. The block is still very much there and hasn't been shifted further east all winter really (unfortunately), but it does look to sink south as lower heights are slightly too far west to prop it up. ECM at least gives us a crumb of comfort and one way in which the block could still deliver cold later on this month.

The reason I like this GEM chart so much is that the low to the W of Iberia shuts the door to any meddling heights from the Azores high ridging into Europe and keeping the freezer door shut for the far west of Europe. I am concerned though, that given the Azores high's propensity to ridge into Iberia/France all winter that the ECM's solution might be closer to the money and the Scandi high will eventually sink a bit further south than we want if it is snow we are after. Really hope I am wrong.

Large amounts of uncertainty clearly persisting into the medium range this morning, but the ECM gets to a place that I feel looks promising. If those height rises near Hudson Bay verify as per the 00Z run and we see the most potent segment of the polar vortex dropping in around Svalbard for a while then the dice could quickly start to roll in our favour. As energy then starts to head SE and potent cold builds up to the north it could be the perfect antidote to the mid-latitude blocking boredom we've had to endure for the winter so far. Next few days will be interesting to see if this is an emerging trend and firms up or not, but I really hope it does as we still have a good few weeks of winter to play with...

Much keener on the GFS run this morning than the ECM, as the latter takes the low in the W. Atlantic north (putting more energy into the northern arm of the jet, which will prevent our high pressure from drifting far enough north for Scotland to join in the cold E'ly flow). By contrast, the GFS at T+240 has high pressure building out to the NW of the UK, with low pressure south of it, propping up the anticyclone and, ultimately, reinforcing the low heights over central and southern Europe, thereby aiding the longevity of the cold spell. Still looks like a milder few days for Scotland and the far north early next week in any case. ECM at T+216: GFS for the same timeframe: