About That Alpine Snow

The northern and western Alps are generally off to a good start to the ski season, but there are some caveats.  Given our current snow drought, I thought we would have a look, focusing on the eastern Alps of western Austria and northeast Italy.  

Below is an analysis of total snow depth from the avalanche.report.  This is based on computer modeling and includes observations in colored circles.  Due to frequent northerly and northwesterly flow storms, snow depths are greatest (and impressive) at upper elevations along the northern Alpine Rim, especially near the Arlberg Pass (resort areas of Zurs, Lech, and St. Anton) and in the Karwendal Alps immediately north of Innsbruck.  Snow depth is lower, but still very healthy for this time of year, in the inner Tyrol (resort areas of Ischgl, Obergurgl, Sölden).   On the other hand, the Dolomites of Northeast Italy are really hurting.  The highest snow depth I could find there was 53 cm (about 21 inches).  This is because northerly and northwesterly flow puts them in the precipitation shadow of the Alps and often results in a warm downslope wind known as the Foehn (Föhn in German).   

Source: https://avalanche.report/weather/map/snow-height

On the other hand, there have also been some exceptional warm spells in the northern Alps and a quick look at the map above reveals that there is no snow at valley level in the Inn Valley and relatively little snow at lower elevations near the Arlberg.  For instance, there is only 67 cm reported in Warth (1490 m/4888 ft) and 40 cm (16 inches) in St. Anton (1285 m/4215 ft).  So, there is an incredible gradient of snowfall with elevation in that area from low amounts in the valleys to exceptional amounts at mid- and upper-elevations.  In St. Anton, for example, one goes from 40 cm/16 inches in town to 216 cm/85 inches at the Galzig Schneeestation (2025 m/6643 ft) and 352 cm/139 inches) at the Ulmerhütte (which is also right on the divide).  

A couple photos show the situation quite well.  The first is from just south of Obertsdorf, which is in the Bavarian Alps of Germany just north of the Arlberg, near an elevation of 800 m/2624 feet.  There is no snow at valley level.

Source: https://www.foto-webcam.eu/webcam/scheibenhaus/2023/12/26/0940

Similarly, the view looking south across the Inn Valley above Innsbruck shows no snow on the valley floor and in fact no natural snow cover even on north facing aspects up to about 1300 m/4265 ft. If you take a close look, you can see the artificial snow covering the lowest ski runs of the Patscherkofel just to the left of center. 

And it is still exceptionally warm.  In fact, at the time the photo above was taken, it was 4.5˚C/40F at the camera location, which is at 1921 m/6300 ft.  

The combination of heavy snowfall interspersed with warmth resulted in snow creep issues, such as this fissure that opened up on a ski run above St. Anton about a week ago.

Source: https://www.tt.com/artikel/30871819/pisten-brachen-weg-nasser-schnee-macht-tirols-skigebieten-zu-schaffen

The steep, grassy slopes of the Alps are also prone to glide avalanches, and they have been a big concern in the recent avalanche reports.  Glide avalanches typically occur on smooth surfaces, with the entire snowpack releasing down to the ground.  Melt water often lubricates the ground to enable this to occur, with glide cracks opening up over time as the snowpack begins to creek down the slope before catastrophically releasing. A friend sent me the photo below a few days ago of some impressive glide avalanches. I think these are from near Samnaun, just south of the Austrian border in Switzerland.

So, lots of snow at upper elevations in some portions of the Alps.  The analysis above shows quite nicely how variable snowpack and snow conditions can be with region and elevation in this part of the world. I suspect there are many people traveling over the Brenner pass from Italy to Austria in search of snow this holiday season.

Visit to Storm Peak Lab

Storm Peak Lab is a permanent mountain-top research facility located at 3220 m (10,564 ft) near the summit of Steamboat Springs ski area.  The lab has been in existence for more than 40 years, with equipment initially operated from a small trailer and now as a permanent facility.  

Storm Peak Lab

This summer, ownership and operation of the lab transition from the Desert Research Institute to the University of Utah under the direction of Dr. Gannet Hallar, with significant support for the lab coming from the National Science Foundation and other agencies.  Earlier this week, I made my first visit to the lab with a group of undergraduates who are participating in our Research Experience in ALpine Meteorology program (REALM).

REALM students and other visiting scientists and students at Storm Peak Lab

There are remarkably few mountain-top or high-altitude scientific laboratories in the world that collect a comprehensive suite of meteorological, cloud, trace gas, and other observations.  The lab is quite literally packed with instruments, some permanent and some temporary.  These instruments measure a remarkable array of variables including trace-gas concentrations (e.g., carbon dioxide), cloud condensation nuclei, ice nuclei, etc. etc.  Such measurements are critical for understanding air pollution, cloud and precipitation processes, and climate change.  

Gannet Hallar describes the instruments at Storm Peak Lab

The students and I learned, for example, about mercury in the atmosphere, its natural and human sources, and how measurements at the lab are advancing our understanding of its sources and sinks.  

Dr. Lynne Gratz of Colorado College presents her latest work on mercury in the atmosphere

We're excited for Storm Peak Lab to be a University of Utah facility.  It will be a game changer for us, not only for mountain meteorology, but also interdisciplinary mountain studies, education, and outreach.  With support from the National Science Foundation, I am planning on taking a group of graduate students there in the fall as part of my graduate-level mountain meteorology course.  

Northern Stau

If you follow ski racing, you know that this Friday and Saturday should each have featured a men's downhill and Sunday a slalom on the famed Hahnenkamm in Kitzbuhel, Austria.  Instead, the meteorologists won the day and the Saturday downhill and Sunday slalom were switched due to anticipated heavy snowfall on Friday night and Saturday.  

Indeed the Saturday snow did materialize and Dave Ryder won Great Britain's first world cup race as he unleashed a great second run and the top skiers from the first run flailed in the difficult conditions.  

It's GOLD for @daveryding in the Kitzbühel Slalom @fisalpine World Cup!!

BRITAIN'S FIRST EVER ALPINE SKIING WORLD CUP GOLD - laying down a marker for @Beijing2022 next month!

👏👏👏👏👏 pic.twitter.com/HVvz2ceaKE

— GB Snowsport (@GBSnowsport) January 22, 2022

Ryder learned to ski on plastic slopes in England and has been knocking at the door for a win for a long time.  Great to see him get his first win at the age of 35, a day after Johan Clarey of France came in 2nd in the downhill at 41.  I believe Clarey is the oldest skier to podium in world-cup history.  

Getting back to meteorology, the snow was produced by a common eastern Alps storm type know as Nord Stau or northern blocking.  These storms occur when there is a high pressure west of the Alps and low pressure to the east, resulting in moist, northerly flow directed towards the Alps.  Often, the flow is stable and the low-level airmass is unable to surmount the massive Alpine barrier.  As a result, the low-level flow is blocked and becomes westerly near the Alps.  This can yield heavy snowfall upstream of the Alpine foothills and terrain near the northern Alpine Rim.  Often there is a dramatic weather near the Alpine Divide, with dry conditions or even clear skies to the south.

This is precisely what happened today.  I've provided a sketch below on the MODIS imagery from midday.  Northerly flow over Germany to the north of the Alps and low-level westerly flow near the Alps, with a transition from cloudy and snowy near and north of the Alpine Divide to clear skies to the south.  

Source: NASA

Evidence for this flow pattern is apparent in the 1200 UTC sounding from Munich, which is about 50 km north of the Alpine foothills.  The low level flow is westerly, but veers to northerly at about 900 mb, or 1000 meters above sea level.  

Source: University of Wyoming

Nord Stau can produce more in the lower terrain near the northern Alpine Rim than on the much higher Alpine Divide to the south.  Below is the 6-hour difference in snow depth analysis for the region for the period ending at 5 AM local time this morning.  Snowfall is clearly greatest near and along the Austrian-German border north of Kitzbuehel where peaks are generally around 1500-2500 meters high.  Snowfall declines to the south along the Alpine Divide where there are many peaks over 3000 meters.  Practically no snow fell south of the Alpine Divide.  

Source: https://avalanche.report/

If you woke up this morning in Innsbruck, you could have elected to ski powder near the northern Alpine Rim or traveled through the Brenner Pass for sunny skies.  Your choice. 

Recent Precipitation Extremes

Here are a couple of ongoing examples of precipitation extremes for your entertainment this Thursday.  

We've discussed the heavy snowfall in the Alps in previous posts.  I've found a new winner for extreme snowfall during the event, the Connyalm at 2105 meters in the Gailtaler Alps of East Tirol in Austria, just to the north of the Porzehütte site we've discussed previously.

The time series below shows a remarkable increase in the height of the snowpack (HS) from about 20 cm at about 1800 CDT on 4 December to nearly 300 cm at 1200 on 9 December.  

Source: https://avalanche.report/weather/stations

If you prefer US units, that's an increase in snow depth of about 110 inches in 114 hours (4 3/4 days).  Remarkable stuff.  

The camera at that location was down when I tried to pull it up.  Here are a couple of photos from the region to remind you of the beauty of snow.

Source: https://www.megacam.at

https://www.megacam.at

Shifting gears to Utah, it's quite remarkable how dry it has been since July 1.  From then to yesterday (December 9), total precipitation at the Salt Lake City International Airport was only 1.52 inches, easily the lowest on record.  

Source: NOAA Regional Climate Centers

In fact, there's only one other year under 2 inches for that period since records begain in 1874, 1958 (1.80 inches).  In addition, 1.52 inches is actually less than what Las Vegas averages for July to November (1.92 inches).

The US drought Monitor now shows a huge chunk of the state in exceptional drought, including Salt Lake City and the central Wasatch.  

Forecasts are more optimistic for the coming week than they have been in a while, with a series of troughs coming through.  Let's hope they produce.  

Alpine Storm Update

As we sit mired under a ridge in Utah, we look once again to the Alps for interesting mountain weather. 

The storm discussed in prior posts has had quite an impact on the southern Limestone Alps of Austria and northeast Italy.  The Tyrolean newspaper Tiroler Tageszeitung reports level 5 (highest possible) in the East Tyrol, with power outages and mudslides in other areas. 

Source: https://www.tt.com/artikel/30766028/wetterchaos-in-tirol-lawine-auf-haeuser-in-osttirol-strassen-in-nordtirol-gesperrt?slide-id=1

The Tirol Avalanche Report shows level 5 avalanche hazard in the East Tirol and portions of the Dolomites.  Heavy snow also fell along the Carnic Alps further east and south of Villach, Austria, not covered by the Tirol Avalanche Report.

Source: https://avalanche.report/bulletin/latest

In fact, one of the more impressive meteograms I could find was from the Porzehütte, an Austrian Alpine Club hut on the Carnic main ridge south of Obertilliach (red dot below) where the height of the snowpack (HS) climbed from about 20 cm to 199 cm in less than 2 days.  That's a snowfall rate of about a meter (40") per day.  The water equivalent of that snowfall is around 250 mm (10"), so this is some high-density base builder.  

Source: https://www.lawis.at/station/

A look at avalanche reports for mountain areas around Cortina and elsewhere not covered by the avalanche reports above shows level 4 (high) danger.  Snow levels in that area were fairly high.  Observations from Seiser Alm Zallinger at 2055 meters above Val Gardena show temperatures for much of the event hovering near 0˚C.  Snowpack height observations are spotty, but show an increase of about 100 cm.  

Source: https://avalanche.report/weather/stations

At lower elevations, rain and wet snow has fallen.  An example is the village of Castelrotto at about 1000 m.

Source: https://www.seiseralm.it/en/webcams.html

It would be great if we could get a good base builder storm like that.  How about a multi-day storm with 40-70 inches of high density snow and a snow level of around 6500 feet so we can continue COVID hikes in the foothills?  

One can dream.

Contrasts Across the Alps

In the previous post (An Optimistic Snow Forecast) we discussed a developing storm in the southern European Alps, with snowfall developing in the southern Limestone Alps today and becoming heavy through Saturday.

It's worth taking a closer look at the contrast that exists across the Alps during these situations, as when the southern Alps have great upslope, the northern Alps have downslope winds, known as Foehn.

I'm going to use images from two web cams from the great https://www.foto-webcam.eu/ web site. The first is from San Cassiano near Alta Badia in the Dolomites.  The cam faces roughly westnorthwest.  The other is from Seegrube in the Nordkette range above Innsbruck.  The cam faces roughly south and looks toward Brenner Pass and the crest of the Alps.   

Source: maps-for-free.com

With flow from the southern half of the compass, San Cassiano is on the windward side of the Alps for this storm.  Prior to the storm, on December 1st. there was little to no natural snow evident in the area.  

Things are beginning to change, however, and snowcover is evident today, with more on the way.

Meanwhile to the north of the Alps, downslope foehn is developing.  The series of images from Seegrube shows significant change from yesterday when cloud cover filled the Inn Valley and also lingered on the Alpine crest (top photo below).  Overnight, the low clouds cleared out as downslope Foehn developed.  Clouds on the Alpine crest deepened with the increasing southerly flow.  By today, snow was falling on the Alpine crest and spilling over into the mountains and Wipptal (the Wipp Valley, which descends from Brenner Pass), but one can see some sun in Innsbruck. 

This is a very common occurrence in the Alps with stark contrasts from one side to the other during storms.  It does work both ways.  There are situations when the north side gets heavy snow and the south side is dry (see Stau Storm).  In some seasons, one side of the Alps sees more storms than the other, and a quick trip across or under the Alps can lead to better (or worse) snow. 

Knowledge is power, but weather knowledge is powder power.  

An Optimistic Snow Forecast

I knew that headline would get your attention, but sadly it doesn't apply to northern Utah, but instead the European Alps near and south of the Alpine crest.  

The large-scale setup is related to the high-amplitude flow pattern that is dominating the northern hemisphere.  Over the next couple of days, this pattern features an amplifying ridge over the north Atlantic and a deepening trough over western Europe, as depicted in the GFS dynamic tropopause (upper-level) flow forecast for 1200 UTC Saturday 5 December.  

This is a very slow moving pattern that leads to intense water-vapor transport toward the Alps from the Mediterranean and Adriatic Seas.  Such vapor transport is strongly influenced by flow interactions not only with the Alps, but also with the Apennines of Italy and the Dinaric Alps of Croatia and the Balkan States.  This can be seen in the GFS forecasts of 925-mb (roughly 750 meters above sea level) wind, moisture transport (color contours), and 3-hour accumulated precipitation (color fill).  At 1200 UTC 4 December, strong moisture transport is occurring from the south-southwest over the Gulf of Genoa and, due to flow blocking by the Alps, up the Po Valley.  This often leads to heavy precipitation in the region around Lago Maggiore region of northeast Italy and southern Switzerland (white dot).  

A day later, at 1200 UTC 5 December, as the storm shifts eastward, south-southeasterly flow up the Adriatic leads to strong moisture transport toward the Southern Limestone Alps, including the Adamello Alps (blue circle), Ortler Alps (orange circle), and Dolomites (white circle).  These areas will see very heavy precipitation.  

A meteogram for the Dolomites near Canazei shows 184 mm (7.2 inches) of precipitation by 0600 UTC Sunday, most falling since 1200 UTC Friday, with an increase in snow depth of over a meter.  

Enjoy watching a storm in another part of the world if we can't have one here. 

Alpine Snow Update

Upper elevations of the Italian and Austrian Alps near the Alpine divide and south continue to see snow.

Based on reports to berfex.com today (either morning or afternoon local time), below are some selected new snow or mountain snow depth totals from Italy:

Arabba (Veneto): 100 cm new, 130 cm snow depth at 2500 m
3 Zinnen Dolomiten (South Tyrol): 85 cm new, 112 cm snow depth on upper mountain
Suldan am Ortler (South Tyrol): 80 cm new, 200 cm snow depth at 3250 m
Schwemmalm-Ultental (South Tyrol): 70 cm new, 140 cm snow depth at 2625 m
Gröden/Val Gardena (South Tyrol): 60 cm new, 130 cm snow depth on upper mountain

And in Austria:

Pitztaler Glacier: 60 cm new, 230 cm snow depth at 3440 m
Hintertux Glacier: 40 cm new, 175 cm snow depth at 3250 m
Kaunertaler Glacier: 30 cm new, 240 cm snow depth at 3108 m
Sölden: 20 cm new, 282 cm snow depth at 3000 m

For those of you who miss winter, below is this morning's avalanche report for the Alpine Divide along the Austrian-Italian border and the South Tyrol.

Source: avalanche.report

And a few photos from the ZAMG (Austrian weather service) taken in East Tyrol and Carinthia in southern Austria on Friday.

Now, just to blow your mind, in the wake of the cyclone, here's snow from Algeria. 

More winter scenery coming from Algeria! This was taken yesterday in Batna.

Photos by Падающая Звезда - posted with permission pic.twitter.com/v66kodSlfg

— severe-weather.EU (@severeweatherEU) November 17, 2019

I miss winter!

Looking for Snow?

Ridging continues to dominate the weather of the Wasatch after Mother Nature teased us in late October.

It is, however, snowing in portions of the Alps.  In particular, upper elevations of the Tirol, East Tirol, Carinthia, Süd Tirol/Alto Adige, and Trentino are off to a great start to the ski season.  Mountain snow depth listed below from Austria are quite solid for mid November, especially at Sölden and Obergurgl-Hochgurgl in the Ötztal Alps. 

Below is the scene from earlier today (noon local time) at Obergurgl, where wet snow was falling at the base. 

Source: https://www.bergfex.com/obergurgl-hochgurgl/webcams/c1566/

The situation today, illustrated below using short-range GFS forecasts, is similar to previous storms this year with a strong low-level flux of moisture (red contours) from the Mediterranean and Adriatic Seas impinging on the Dolomites and Alpine main divide.  The Ötztal Alps, indicated by a star, are not the snowiest part of the Alps, but do extremely well in these flow patterns.  Additionally, they benefit from altitude (numerous peaks over 3000 meters) since these storms can sometimes be warm.  

The importance of altitude today is well illustrated by observations from the Deponie observing site at 1488 m just south of Sölden in the Ötztal valley show surface temperatures right at or just above 0ºC since heavy precipitation began earlier in the day.

Source: https://www.lawis.at/station/

The noon web cam image from the village of Sölden suggests it observed rain, at least during the early stages of the event.  

Bottom line is that at upper elevations, portions of the Austrian Alps are off to a really fine start.  There's more snow coming too.  Note, however, that all generalizations are wrong and you shouldn't assume that this means everywhere in Austria is off to a roaring start.  Like politics, all meteorology is local, especially in the Alps. 

Epic Eurostorm

The weather has been boring in Utah of late, but not in the southern Alps and the Mediterranean Basin.

Medicane

A powerful Mediterranean cyclone known as a "medicane" and named Detlef formed on 11 November, just north of the coast of Algeria.  Medicanes are a sort of hybrid between tropical and midlatitude cyclones and feature a shallow warm-core structure. 

For more, see this Severe Weather Europe post. 

Acqua Alta

Detlef ultimately merged with another midlatitude cyclone, forming a strong system that sat over the Tyrrhenian Sea between Sardegna, Sicily, and mainland Italy from 0000 UTC Tuesday 12 November through 0300 UTC Wednesday 13 November.  This resulted in an extended period of southwesterly flow over the Adriatic, driving water into the Venice region.  Below is a 3-hour GFS forecast valid at 2100 UTC Tuesday 12 November (1000-mb wind vectors) illustrating the situation, with a very long fetch extending northwestward up the Adriatic Sea to Venice. 

This apparently led to a major Acqua Alta (high water) event that rated as the 2nd highest on record, topped only by an event in 1966. 

St. Marks Square, Venice.  Source: Marco Bertorello/Getty Images, https://slate.com/news-and-politics/2019/11/venice-italy-pictures-video-underwater-flood-storm.html

Venice is becoming increasingly vulnerable to Acqua Alta events due to sea level rise and land subsidence (more on the latter at https://www.livescience.com/19195-venice-sinking-slowly.html).  Gates are being installed to help protect Venice from these events, but the project has been mired by delays and corruption.  Venice is overwhelmed with tourists, but despite overcrowding the entire place is a work of art built right on the water.  

 It will be exhibit A in the battle against sea level rise in the coming decades and centuries.  What will happen to great cities like this in the future? 

Alpine Snow

You want snow, head to the Alpine Divide along the Austrian-Italian border and points south.  Below is the current snow depth analysis from ZAMG (the Austrian Weather Service) and the Tyrol-Südtirol-Trentino avalanche services.  As usual, there are large altitudinal gradients in snowfall, but cherry picking a few observations reveals 184 cm at Rettenbachferner (2970 m) near Sölden, 123 cm at Schnalls Teufelsegg (3035) in the Italian Otztal Alps, and 93 cm at Abtei Piz la lla (2050 m) in Alta Badia, Italy.

This is just the start.  Below is the snowfall forecast through Sunday morning showing 70-90 cm more for the higher elevations of the Dolomites and 50-70 cm for the higher elevations of the Ötztal and Tux Alps southwest and southeast of Innsbruck, respectively.  Forecast totals are highest south of the Alpine divide and north of Lienz.

I'm starting to think of booking a trip.  You should pitch in to cover the costs so I can take the Steenburgh effect with me. 

Swiss Glaciers Continue Their Retreat

The Pizol Glacier in the Glarus Alps of northeastern Switzerland is one of 500 small Swiss glaciers that have disappeared since 1900.  Photo: Matthias Huss/Swiss Academy of Sciences

It was an exceptionally good snow year in the northern Alps this year, and May was quite cool.  I was wondering if this might lead to a net positive mass balance for Alpine glaciers this year, but at least in Switzerland (and I suspect elsewhere), it wasn't to be. 

As reported today by the Swiss Academy of Sciences, glacier melt levels during this summer's heat waves reached record levels and in the net, glacier mass loss for the year exceeded accumulation, yielding a net mass loss of 2% of Switzerland's total glacier volume.  Over the past five years, the rate of mass loss exceeds anything previously observed in records that go back for more than a century.  

Perhaps most disheartening is that eastern Switzerland saw exceptional snows during the winter, yet losses were higher than average for the past ten years.  I haven't seen the latest from Austria yet, but it experienced a similar winter and summer compared to eastern Switzerland and I suspect the story will be similar.  Below is a tweet from @robbieshone on October 13 showing scientists taking field observations to determine the annual mass balance of the Hintereisferner, which is Austria's best studied glacier.

I joined a small group of #glaciologists led by Dr. Rainer Prinz from the ACINN @uniinnsbruck, to carry out the annual mass balance of the Hintereisferner. Rainer's team spent 2 days undertaking numerous #scientific jobs across the whole glacier where t... https://t.co/39OuGlJf7s pic.twitter.com/W3Nu4Y2z6y

— Robbie Shone (@robbieshone) October 13, 2019

Below are photos of the Hintereisferner (from https://www.foto-webcam.eu/webcam/hintereisferner1/) in mid June and early August, illustrating the loss of the remarkable snowfall from the 2018/19 winter. 

Sabbatical Ends with European Heatwave

We leave Innsbruck in less than 24 hours.  I finished my grades for my classes on Wednesday and we've been trying to enjoy our final couple of days in Innsbruck. 

Things have changed a lot during our stay.  We arrived in mid January after an incredible storm cycle that left the northern Alps buried.  The Inn Valley was a winter wonderland during the first few weeks of our visit.

In contrast, June will go down as the warmest on record in Austria and the last few days have been blisteringly hot.  All-time June temperature records were set two days in a row in the Tyrol with a 36.7ºC on Tuesday in Innsbruck and then a 37.5ºC in Imst on Wednesday.  The latter is 99.5˚F in US units and would qualify for a max of 100 with round up.  The previous June record was 36.6˚C.  A photo taken from the same spot as above shows a nearly snow-less scene, with hazy skies. 

We feel fortunate to be at about 600 meters above sea level and in a modest sized city.  Areas of France, Spain, Germany, and Italy have eclipsed 40˚C.  The BBC is reporting today that Carpentras recorded the highest temperature ever in France (44.3˚C).

Many cafes do not open here until 9am, but the Tomaselli Gelateria was open at 8:30 and already had a line. 

And the Tiroler Tageszeitung ran an article (translated below by Google Scholar) providing all important information that deodorants work and don't cost much. 

For most Tyroleans, relief isn't necessarily too far away.  One can go to a cool stream or lake or hop a ride on a cable car, as we did this morning to 2300 meters..

But more seriously, this is a very severe heat wave and it is the first of the year.  Air conditioning is relatively uncommon in much of Europe.  The only cool places in Innsbruck, for example, are grocery stores and drug stores.  Mortality and morbidity rates rates will likely be elevated in many areas.  Relief cannot come soon enough.