Blessed Weather

Here's the latest satellite image and Arpege wind gusts and precip charts for this Saturday morning (18 Nov). Quite a rare event this, with only 100 such storms between 1947 and 2011 according to Wikipedia: https://en.wikipedia.org/wiki/Mediterranean_tropical-like_cyclone

I wasn't sure where to post this, so forgive me if it's not appropriate here, but here's the latest thoughts from MO man John Hammond, posted today, as he discusses "Battleground Britain" and the influence of stratospheric winds on current weather patterns. Extracts: We’re set to see some dramatic contrasts in the weather as November draws to a close. Cold and warm air will be vying for supremacy across our shores, generating some ‘interesting’ weather, to say the least. Scientists are looking for signs at the very top of the atmosphere. The relationship between stratospheric winds and our weather patterns at ground level is still only beginning to be understood. But it’s known that sometimes these two atmospheric zones ‘hook up’ and blow in tandem. Other times, as at present, they seem strangely disconnected. If strong westerly winds in the stratosphere start to drill down through the atmosphere, our jet stream will become super-charged. What does that mean? In all likelihood, a more clear-cut mild, wet and windy period of westerly winds would result. However there are currently no clear indications of a ‘hook-up’ between the top and bottom of the atmosphere. My hunch is therefore for a continuation of the current meanderings of warm and cold air, which the computer models will continue to struggle with. Full article: https://weathertrending.com/2017/11/17/horizon-battleground-britain/

Great stuff Julian - looks good! And if you want to show just the new snowfall that is forecast to fall (rather than starting the sequence showing what's already there and then being added to), choose the "Couche de neige depuis 0h" (snowfall since 0 hour). e.g. here's the new snowfall from this Fri through to Monday.....

Hi Chris. Good question and you've got me wondering. Hopefully it's not Himalayan Balsam, which is actually classed as a major weed problem on river banks. I've zoomed in on the photo but can't tell. Hope it isn't but I'll take another look when I'm over that way again. Here's a stock photo of the weed - looks ominously similar:

What a nice day for a walk! Although the temp only reached 7.8C here, as Katrine says above, it felt pleasant in the plentiful sunshine. I snapped this photo of the swans on the local river (Brett) this afternoon. The 4 youngsters were born back in the spring of this year. Mum & Dad are in the background keeping an eye on them!

Probably on hired skis!! I got over enthusiastic one early season in the Alps and ended up with deep gouges in my skis from the rocks and stones just below the surface!

Looks like Jo!

The latest update from Berlin (17 Nov) shows the Zonal Mean Zonal Wind of the strat vortex at 10hPa 60N is forecast to reduce from 34 m/s today to 28 m/s by Day 10 as the stronger flow that was filtering down to the lower strat retreats back up. But bearing in mind that the record low zonal wind speed for this stage of the season was 5.4 m/s in Nov 2009 I suspect this will not be enough to stop the strat and trop vortex coupling in the short-term? If so, it’s good to see possible wave forcing appearing in the forecasts to hopefully aid disruption. Berlin charts for today, day 5 and day 10 with 10hPa 60N marked with a cross.

Great to pull back the curtains and everything white with frost. Got down to -2.4C in IMBY. Here's the EA leader board this morning:

Nice to read that the snow that's fallen on the Scottish mountains over the last couple of weeks might well last through the season now! And hopefully there's plenty more to come over the next 4 or 5 months that will fill every crag and corrie to the brim!!

I'd be grateful if one of the strat experts on here could check my interpretation of the JMA Zonal Mean Zonal Wind latitude-height chart please. My take: the zonal winds at 10 hPa 60N are westerly and slowly ticking up (yesterday 33.6 m/s, today 34.7 m/s) and that the stronger winds are slowly descending down through the strat. the winds at 30 hPa over the equator are easterly and thus show an e-QBO. And finally, what is causing the burst of stronger westerlies at 300 hPa 30N? I don't understand that one! Thanks in anticipation.

Oh dear. Another day of grey nothingness! No sun, wind, rain or snow...... nothing but depressing grey. But in ten days time I'm off to the Yukon in Northern Canada for two weeks to visit my daughter and grandson. The prospect of seeing them, the weather over there, and the prospect of skiing their local mountain is making me REALLY excited. How's about this week's forecast for where they live. I'll be wearing two woolly hats at the same time and I won't care what colour!!

Fascinating sequence from NASA showing how Ophelia picked up the dust (brown) from the Sahara and then the smoke (white) from the fires in Spain and Portugal and wafted it over the UK to give us those spectacular red skies and sunsets.

You're not in Bologna are you SS?

If my memory serves me correctly, compared with previous images I've seen from that webcam, that appears to be a very good depth of snow on that piste for this stage in the pre-season build-up Paul? And from model output, looks like more cold and snow is due this coming weekend and into early next week. I'm loving this current 'rinse and repeat' weather pattern - so much better than previous years with a huge Euro-slug High sat over a warm and dry Europe! P.S. Hope you're enjoying being back in Katschberg - I'll pm you later.

Dr. Judah Cohen doing some 'thinking out loud' about the polar vortex and various scenarios going forward in his latest weekly update (13 Nov): "The second item giving me restless nights is the strengthening stratospheric polar vortex. Currently the troposphere and stratosphere are uncoupled. The stratospheric PV is predicted to strengthen while the tropospheric circulation at high latitudes is predicted to become increasingly perturbed. The troposphere and stratosphere can remain uncoupled for long periods in the winter but that is often the exception and at some point the stratosphere and troposphere are likely to couple. How the troposphere and stratosphere couple is an open question in my mind. One possibility is that the perturbed or disturbed state of the troposphere is transferred to the stratosphere and then boomerangs back into the troposphere, resulting in a relatively cold winter across the mid-latitudes of the NH. The other possibility is that the mostly zonal circulation associated with the predicted strong stratospheric PV descends from the stratosphere to the troposphere resulting in a relatively mild winter across the mid-latitudes of the NH. Both scenarios seem plausible to me yet the outcomes again would be polar opposite in regards to resultant sensible weather." Dr. Cohen goes on to outline 3 scenarios going forward, but seems to favour the troposphere and stratosphere coupling in the medium term and a period of more active WAFz or poleward heat transport, leading to an eventual weakening of the strat PV with high level blocking and cold outbreaks into the NH mid-latitudes. He notes this winters' e-QBO could be an influencing factor supporting this scenario. Note this link goes to the latest blog, so the 13 Nov update will be replaced by the next update in a weeks' time. http://www.aer.com/science-research/climate-weather/arctic-oscillation

What can you say about Iain Cameron? The guy's amazing! He can't keep off the mountains and he takes amazing photos!! Another stunner from yesterday: And this fabulous photo from Dr. Rob Lennox of Glen Lyon yesterday:

Beautiful start. Down to 1.2C overnight. Lots of cloud streaming down from the NW threatening to spoil things - hopefully not until much later.

Freezing level has taken its time to drop in some parts of the Alps during this current snowy spell. For example, here's Les Deux Alpes at 1,650m 16.30 yesterday compared with 09.15 today (Mon 13th): But finally overnight freezing level has dropped significantly - here's Ellmau in Austria at 827m this morning: Snow still falling widely this morning - indeed, you can't see anything on many webcams either through poor visibility or the camera covered in snow! A few other webcam grabs: Grindelwald, Switzerand Passo Tonale, Italy And a couple for John - snowing hard in Wengen and the Lauberhorn downhill finish area at 11.00 (local time). Can't see the start hut at the top as its a white-out!!

Nice to see a dusting on the tops of the Pennines today:

Oh my - what a fabulous view from the top of Ben More today!

Temp down to 3.4C overnight. A chilly day ahead with quite a windchill in a stiff wind. I'll be joining @Dami and wearing a woolly hat this afternoon! 15.00 Gusts Windchill

Lol. Have you been on the pop Dami? Oh hang on.... Is it your Birthday today? Happy Birthday!!

Hi Julian. Go to Meteociel and scroll down to WRF NMM and select the WRF Alpes et Suisse (click on the Swiss flag). When the chart loads on your screen, look just above the chart to the right. You should see a tiny GIF symbol. Click on the GIF symbol and a pop-up loads. Enter the start and finish hour (handy if it's a 384 hour model run as you can select a certain period, but for snowfall accum it's only a 72 hour run, so I didn't alter). I always alter the pause time at the end (Temps de pause à la fin) to 3000ms as I think it helps emphasize the end of the sequence. Then click generate (generer) button and Meteociel starts creating the animation. When Meteociel has finished creating it offers a number of options - you need to copy and paste the top link directly into your post (as you would a tweet). Within a second or two it turns into the animated GIF). Job done!!

So here we go again - all set for another good snowfall across the Alps over the next few days. Here's NMM take on snow accumulation from this morning up to midnight on Mon 13th Nov. Not much today or early Sunday, but really coming down overnight Sunday into Monday: And if I'm not mistaken, we see the -5c 850hPa isotherm appear over the Alps for the first time this season, so freezing level gradually falling down to resort level quite widely. And once again the NW'ly flow kinks upon hitting the Alps to invigorate a Low over northern Italy and give another good fall for more southern Alpine resorts. A great early start to this season - let's hope we can avoid any unwelcome mild spells between now and opening dates! Charts for Mon 13th 03.00: