Blessed Weather

Lovely snowy images from up on Glencoe this morning (Fri 10th): And more to come over the next few days according to Arpege snowfall accumulation forecast up to midnight Monday 13th.

I'm still a learner in here, but we seem to be at an interesting stage in autumnal developments atm with trop vortex struggling whilst up above the strat vortex is looking organised. So presumably a disconnect at the moment and the big question - how will things develop from here? Will the strat filter down or the trop disrupt up?? ECM charts: 500hPa 19th Nov 10hPa 18th Nov

Great output from the models at the moment. I wonder if what we are witnessing is a new 'pattern' in the weather that will regularly occur in late autumn/early winter? With the Arctic so warm nowadays (relatively speaking!) there's a lack of temperature gradient between the mid-latitudes increasingly resulting in a weak, meandering jet and thus further warm air advection into the Arctic region. This seems to be resulting in a tropospheric PV that struggles to get going at this time of year and we get outbreaks of cold air spilling into the mid-latitudes. Our part of the world hit the jackpot in Nov/Dec 2009/10 and more recently the USA has seen bitter weather. Will it be our turn to see the white stuff this year - esp with other drivers such as ENSO, QBO and solar activity all favourable this season? Moving on and apologies for going way off topic..... rather chilly for the Region last night!!

Dr. Cohen has updated his blog today (6th Nov) and has taken on board the negative trend in the AO that the models have been forecasting this last few days. As a result his prognosis for the upcoming season is much more encouraging. Some snippets (my emphasis in bold): For me the most important recent development in the large-scale circulation is the weather model consensus that ridging/positive geopotential height anomalies will consolidate across the high latitudes of the Eurasian sector stretching from Northern Europe to the dateline next week. With the ongoing positive AO, a relatively mild pattern has become established across Eurasia with just localized pockets of below normal temperatures across the entire continent. As a result snow cover advance across Eurasia has once again stalled and Eurasian snow cover extent is significantly less than a year ago on this date. However based on model forecasts, that is about to change dramatically. Currently the only region with ridging/positive geopotential height anomalies at high latitudes across Eurasia is northwest Russia. However those positive height anomalies are predicted to move east while ridging/positive geopotential height anomalies now centered near the dateline are predicted to move west. Next week the two areas of positive height anomalies are predicted to merge forming a bridge of above normal geopotential height anomalies stretching from Northern Europe to Eastern Siberia. This will force below normal geopotential height anomalies further south across the mid-latitudes of Eurasia. Low heights and northerly flow will usher colder temperatures across the mid-latitudes of Eurasia including Europe and especially East Asia. Longer term I do believe that this pattern of northern Eurasia blocking increases the probability of more active poleward heat flux and a weakening or disruption of the stratospheric PV. Severe winter weather across the NH is more likely following a PV disruption. .......the model forecasts also suggest the building of Greenland blocking mid-month and possibly beyond. Greenland blocking favors cold temperatures not only in Europe but in the Eastern US as well. http://www.aer.com/science-research/climate-weather/arctic-oscillation

It's looking blooming marvelous up there John!! Here's the Jungfraujoch this morning (6th Nov): And here's the snowy scene on the famous Hahnenkamm at Kitzbuhel. Great first widespread snowfall. I use the Bergfex site for webcams. Click on "Ski Resorts" for a list of countries and resorts. https://www.bergfex.com/schweiz/

@damianslaw Hi. I was wondering if this thread would be relaunched for the 2017/18 season? There were some wonderful photos of winter scenes posted last year, and whilst there was a little confusion about which thread Scottish mountain posts should appear in, I felt this thread was a great addition. One alternative is to have a "Snow on Scottish & other UK Mountains" thread (but too late for this year?). And if I may raise another point, I feel we should drop the actual years from the titles so the threads just keep running. That way we can easily look back at previous seasons and notable events (e.g. last snow patch on the Scottish mountains) without having to trawl back through dozens of pages (as I've just done to find this!). Thanks. Anyway, I'll crack on.... this was Helvellyn range in the Lake District yesterday.

Actually the good news is there are a number of independent studies that have looked at Dr. Cohen’s ‘theory’ and have found there is a good correlation between Eurasian snow cover growth and extent in October and the subsequent Arctic Oscillation (AO). And I particularly like the fact that the correlation is stronger during winters with a e-QBO (expected this winter). And as if on cue it’s interesting that current model output is suggesting the AO looks set to go significantly negative later this month, so hopefully Cohen will be proved right with his tweet “Let the games begin”. But of course, even a negative AO doesn't guarantee a snowy UK, but as the saying goes, "every little helps" for our snow starved island!! For those interested, some snippets and links from a couple of supporting studies: 1. An Analysis of Eurasian Snowfall and the AO The statistical analysis reveals that the highest correlation to the AO is the combination of the cumulative weeks 41-45 snowfall extent with the week 39-46 rate of snowfall expansion. Adam Turchioe 2013 I quite liked this simple Cohen diagram included in the above study that shows the sequence of impact of snow cover: http://www.atmos.albany.edu/student/aturchio/Presentations/Snow Presentation.pdf 2. How stationary is the relationship between Siberian snow and AO over the 20th century? Both observational and numerical studies suggest that fall (autumn) snow cover extent over Eurasia is linked to subsequent winter variations in the predominant Northern Hemisphere teleconnection pattern known as the Arctic Oscillation (AO). The present study uses the recent 20th Century Reanalysis to explore the snow-AO relationship over the entire 20th century for the first time. Over 1976–2010, the well-documented snow-AO mechanism is found; positive snow anomalies enhance the stationary wave activity from the surface into the lower stratosphere, and this wave momentum deposition weakens the polar vortex, leading to an AO response that propagates downward in winter. Y. Peings et al 2013. http://onlinelibrary.wiley.com/doi/10.1029/2012GL054083/full

Precipitation has been pushing into the Alps from the NW this Sunday morning, starting as rain but freezing level slowly falling as the colder air also moves in, so snow now falling down to around 1,700m. Overnight into Monday should see freezing level fall further to around 1,200m with precipitation continuing through Monday, pushing east into Austria whilst slowly dying out in the western Alps. Here's how this morning has progressed at Courchevel (La Croisette) at 1,750m in the French Alps this morning. Webcam grabs from 08.26 through to midday: Additionally, during late Sunday into Monday a vigorous 'Genoa Low' develops which on its northern flank helps to ensure the southern Alps (particularly Italian Alps) also join in the fun with a period of potentially heavy snow. Here's a BBC Weather tweet about this:

I'm puzzled - did we miss the following report? I've glanced back through the thread and can't find it referenced in any posts but it's very interesting reading that suggests a link between the 2015 cold blob and the heatwave across Europe that year. Furthermore, a cold Atlantic anomaly seems to have preceded other European heatwaves dating back to 1980. Abstract: Drivers of exceptionally cold North Atlantic Ocean temperatures and their link to the 2015 European heat wave The North Atlantic and Europe experienced two extreme climate events in 2015: exceptionally cold ocean surface temperatures and a summer heat wave ranked in the top ten over the past 65 years. Here, we show that the cold ocean temperatures were the most extreme in the modern record over much of the mid-high latitude North-East Atlantic. Further, by considering surface heat loss, ocean heat content and wind driven upwelling we explain for the first time the genesis of this cold ocean anomaly. We find that it is primarily due to extreme ocean heat loss driven by atmospheric circulation changes in the preceding two winters combined with the re-emergence of cold ocean water masses. Furthermore, we reveal that a similar cold Atlantic anomaly was also present prior to the most extreme European heat waves since the 1980s indicating that it is a common factor in the development of these events. For the specific case of 2015, we show that the ocean anomaly is linked to a stationary position of the Jet Stream that favours the development of high surface temperatures over Central Europe during the heat wave. Our study calls for an urgent assessment of the impact of ocean drivers on major European summer temperature extremes in order to provide better advance warning measures of these high societal impact events. Full paper: http://iopscience.iop.org/article/10.1088/1748-9326/11/7/074004/meta;jsessionid=36846BA815A6E3397F71CC09EEA3D084.ip-10-40-2-120

And we're off.....

Shame we've lost yesterday's wonderful weather. Today looking a fairly grey and grim affair for most of us for most of the day. However, from a weather point of view IMHO there's usually something of interest and this morning (08.20) I've enjoyed comparing the tangle of weather fronts over the UK on the fax charts with the cloud image from satellite (you can see those fronts and speckles of shower), and lastly the rainfall radar. Yes I know.... I'm sad...

With regard the exact impact of a warm Arctic we appear to be witnessing a huge experiment playing out in front of us at the moment. But of interest to our little island, the scientific community do seem to agree that the reduced temperature gradient between the Arctic and the mid-latitudes will reduce the 'fuel' that drives the jet stream and increase the frequency of a meandering (meridional) jet and 'stuck' weather patterns. Here's a couple of snippets from a well written article by the Guardian newspaper in Dec 2016. Well worth a read. It’s safe to say [the hot Arctic] is going to have a big impact, but it’s hard to say exactly how big right now. But we are going to have a lot of very interesting weather – we’re not going to get around that one. The clearest connection so far between the melting Arctic and weather is for extreme winter conditions, such as the intense winters that hit parts of North America and northern Europe in 2009-10, 2010-11 and 2013-14, causing record snowfalls and billions of dollars of damage. In those years, the jet stream deviated deeply southwards over those regions, pulling down savagely cold air. Prof Adam Scaife, a climate modelling expert at the UK’s Met Office, said the evidence for a link to shrinking Arctic ice was now good: “The consensus points towards that being a real effect. Full article: https://www.theguardian.com/environment/2016/dec/19/arctic-ice-melt-already-affecting-weather-patterns-where-you-live-right-now Getting back on topic, the October snow cover index has ended up above long-term average, so as Judah Cohen says "let the games begin"!!

October another very dry month for our Region with East Anglia seeing only 28% of the long-term average. Looks like parts of Essex and London were well below, not even reaching 20%!

Looks like it was widespread 'chilly' last night, with the frost capital of our Region only just escaping an air frost:

Chilly here overnight - down to 3.8C - but a pleasant start with thin patchy cloud allowing plenty of early sunny spells, although the band of cloud moving south about to spoil that: It looks like this quiet spell of weather will be replaced over the weekend and into next week by a series of fronts bringing rain and cooler temps down from the NW and if skies clear overnight maybe our first widespread air frost. Sat 4th morning rain Chilly start Mon 6th

The report below was published in the French media yesterday (31 Oct) and gives an insight into the impact of recent weather trends on the glaciers of the Swiss Alps. Uncomfortable reading I'm afraid. As with other Alpine countries, Switzerland offers year-round winter sports on several glaciers including the Titlis glacier at Engelberg, the Theodul glacier at Zermatt and the Allalin glacier at Saas-Fee. It would appear that even these 'ultimate' high level resorts are not immune to longer-term climate trends. Let's hope the coming winter provides some much needed relief for all Alpine glaciers. Swiss glaciers lost 1.5 billion cubic meters this year 1.5 billion m³ less ice on Swiss glaciers in 2016-2017. To hear the gross figure is scary. Putting it in perspective is no less so. The Swiss Academy of Sciences, which published its report yesterday, estimated that this amounted to "a quantity of water that would allow every household in the country to fill a 25-meter pool. If the Swiss are only 8.5 million, and the number of households is lower, it still describes well the annus horribilis lived by the glaciers, which globally lost 3% of volume. This hydrological year also ranks in the three worst of the century, just after 2003 and at about the same level as 2011. The glaciers between the western part of the Bernese Oberland and the Valais (Tsanfleuron, the Plaine Morte or even the Griesgletscher) have suffered the greatest losses, a decrease in average ice thickness of 2 to 3 meters, which is huge according to scientists. Those a little less exposed, like that of the Rhone, do not escape the phenomenon with a meter less. The cause is obviously to be found in the drought and the absence of precipitation of this last year. The volume of mass is an immediate witness of the weather conditions, unlike the length of the glaciers. If this criterion seems the most obvious sign of global warming, it is actually delayed. The effects of the very hot and very dry years will only be seen in a few decades for the average glaciers. Full report in French: http://www.ledauphine.com/haute-savoie/2017/10/31/les-glaciers-suisses-ont-perdu-1-5-milliard-de-m3-cette-annee

Great to have a new thread started for the coming season Julian!! I'm quietly optimistic that this year the Alps will benefit from reasonably frequent polar maritime incursions into Europe this side of Christmas and that resorts will be ready to greet Christmas and New Year skiers/boarders. And to start the ball rolling, this weekend sees colder air bringing snowfall above 1500m for both the Alps and the Pyrenees. Charts for Sun 5th Nov: GFS 850hPa and precip Arpege snowfall accumulation

It felt very seasonal today - just how I like the weather as we head into November as it's (hopefully) a taster of colder weather ahead. Temp down to 3.9C overnight last night, a crisp and sunny morning, followed by a bright but hazy afternoon with a max of 9.4C, and then the temp falling away quickly this evening once the sun went down so it's down to a chilly 4.1C at 20.00. No emoticons available on the Forum tonight, so in old speak today was :-)

Hi Ben. No problem - you're entitled to your views. You're in good company not liking the naming of storms! Judging by the amount of comment on Twitter it has caused a lot of controversy and even some professionals don't like it. The Met Office even seem to have found it necessary to try and counter the negative response with a bit of positive publicity. Personally I'm in the 'like' camp as it does seem to do what it says on the tin (see below). But I don't like the way some elements of the press take it as a green light to go completely OTT with apocalyptic headlines, and I also take your point that we all managed perfectly OK before it started a couple of years back. Final thought - I wonder if part of the problem - particularly for weather enthusiasts - is that naming is down to impact on everyday human life and not any particular weather threshold being exceeded, resulting in the unexceptional becoming exceptional just because it has a name?

And for the record, today's leader board for wind in our neck of the woods. Interesting to see the two highest gusts occurred after 17.00.

Here's the wind graph for my location in Suffolk. Max gust 45 mph at 13.44 (spot on what the forecasts predicted - see my post above) and the graph line showing that winds have been gusting above 35 mph from 11.00 this morning through to latest reading at 18.00. So a rather windy day here, although as others have said, nothing too out of the ordinary for autumn. But if I may point out, not everywhere has got off as lightly as this Region, so all-in-all I think the naming of the storm justified. Here's a tweet from our friend Matt Hugo at 17.55 about conditions in E Lancashire:

The main band of rain associated with Brian has cleared through overnight and it's now a lovely start with a clear blue sky. At the moment there's only the gentlest of breezes but no doubt that will change rapidly over the next few hours. Bournemouth has already had a gust of 46 mph. Here's the expected wind gusts at 16.00 this afternoon for East Anglia: