El Niño Update

The Climate Prediction Center (CPC) issued their June El Niño/Southern Oscillation (ENSO) discussion today (June 11) and it's almost certain to send some people into a tizzy, although those of us in Utah should be cautious about what to expect this coming winter.  

Before diving in, let's first talk about what ENSO and El Niño are.  ENSO is a natural cycle in atmospheric and oceanic conditions in the tropical Pacific characterized by a two to seven year cycle between warm phases (El Niño) in which the easterly trade winds weaken and the central and/or eastern tropical Pacific becomes anomalously warm and cold phases (La Niña) in which the easterly trade winds strengthen and the central and/or eastern tropical Pacific becomes anomalously cold.  

Various indices exist to illustrate the phase (and strength) of ENSO.  None of these is perfect since you are boiling down a complex ocean and atmosphere system to a single number.  I tend to favor the multivariate ENSO index or MEI.  Going back to 1979, the MEI has fluctuated between about -2.5 and 3.  Values greater than one indicate moderate to strong El Niño conditions.  Values less than one indicate moderate to strong La Niña conditions.  Two of the strongest El Niño events since the start of the 20th century are evident below: 1982-83 and 1997-98.  The 1925-26 El Niño is also in there amongst the strongest El Niños since 1900.  

Source: https://psl.noaa.gov/enso/mei/

As summarized in the CPC discussion, El Niño conditions, characterized by above-average sea-surface temperatures (SSTs) in the central and eastern equatorial Pacific, over the past month.  The figure below shows the departure of sea-surface temperatures from average for the week centered on 3 June and illustrates the anamalously warm SST not only in the central and equatorial Pacific, but also along the South American coast (as is often the case during El Niño).   

Source: CPC

There has been a lot of talk in the media about this being a "super" El Niño.  CPC doesn't use such flamboyant language, and in their May update they were very careful not to heavily weight the possibility of a strong El Niño, but in this June update they say the odds are stacked for a strong one:

"There is a 63% chance of a very strong El Niño during November-January [Fig. 8] that would rank among the largest El Niño events in the historical record going back to 1950."

So a very strong El Niño is not a lock, but is more likely than not.  At this lead time, that's probably the strongest confidence you are likely to see from CPC about a very strong event.  

However, and this is important for Utah skiers to consider, they also add the caveat:

"Even very strong El Niño events do not lead to the expected impact everywhere, but stronger events can more significantly tilt the odds in favor of expected outcomes."

And what are those expected outcomes?   For December-February Precipitation, CPC indicates greater than average odds for above normal precipitation across mos of the southern US including the southwest and below normal precipitation in the northwest interior.  As is often the case, there's no strong weighting for northern Utah.  

Source: CPC

One of the reasons for this is that there has been a lot of variability in precipitation in December to February during strong El Niño events. Below are postage stamps of precipitation during strong El Niño events so look for yourself.  

Source: CPC

I expect a lot of talk about what happened during 1982/83 and 1997/98 since those are the two strongest El Niño events.  Both of those events produced above average and very significant precipitation in California, the Wasatch, and Arizona.  At issue is whether or not those two "very strong" events are a reasonable sample or if the range of strong El Niño events that includes those and other events that were not quite as strong is a more reasonable representation of the range of possibilities.  As winter approaches, perhaps numerical seasonal forecasts will also have something to say, but I'm inclined to say that what will happen with precipitation this coming December to February is still up in the air.  There's no loading of the dice yet.  

That said, there is some loading of the dice that December to February will be warmer than average.  

Source CPC

That doesn't necessarily mean a repeat of last season.  A lot will depend on storm characteristics that we cannot anticipate this far in advance.  

Keep calm and carry on.  

The End Is Nigh

 The seasonal snowpack at Alta is nearly gone as indicated by yesterday's Mt. Baldy web cam

Source: https://www.alta.com/weather

and observations from Alta-Collins which indicate a total snow depth of 8 inches. 

Automated snow depth observations are such that the instrument might still suggest a few inches of snow on the ground when there is none.  That said, the end is nigh even with the overnight frontal passage, which might only delay the inevitable a day or two. 

Meanwhile, in the Alps, it is snowing at upper elevations!

Source: https://www.foto-webcam.eu/webcam/zugspitze/

Climate Change and Nordic Skiing

The vast majority (nearly all) studies examining the impacts of climate change on skiing focus on Alpine skiing resorts.  However, the reality is that Nordic (i.e., cross-country) skiing is far more vulnerable to climate change as anyone who has a long tooth and skis at Mountain Dell or Round Valley has observed.  

The primary reason for this is elevation.  As an example, below is a photo that I took from the summit of the Rangger Köpfl, a 2000-meter peak from which one can see the Wetterstein Alps and Karwendel Alps of Germany and Austria.  South of the Wetterstein Alps and west (left) of the Karwendel Alps sits the Seefelder Plateau, a famous cross country region that hosted the 2019 Nordic World Championships and has about 245 km of trails connecting the villages of Seefeld, Leutasch, Mösern, Reith and Scharnitz.  

With elevations around 1200 meters, the Seefelder Plateau is promoted as a snow-reliable cross country skiing region.  However, this is still an elevation that is quite vulnerable to climate change and lower than the adjoining Rosshütte Alpine ski resort (also pictured) which extends from 1230 to 2064 meters. 

Consistent with the Seefelder Plateau region, Nordic resorts often lie at relatively low elevations, whereas nearby Alpine resorts reach to higher elevations.  To illustrate this, the figure below shows the mean elevation of Alpine (downhill) and Nordic (cross-country) ski areas in the Alps (AT=Austria; DE=Germany; IT=Italy; CH=Switzerland; FR=France; SL = Slovenia.  There is a clear bias to lower elevations for Nordic ski areas that is especially pronounced in the eastern Alps (Austria and Germany).  The bias is not as large in the western and southern Alps where Nordic ski areas have higher elevations, although unlike Alpine ski resorts, there are no Nordic resorts with mean elevations above 2400 meters.  

Source: Schilling et al. (2026)

Nordic resorts are so vulnerable to climate change because negative trends in snowfall and snow cover are largest at lower elevations.  In other words, the snowpack will suffer more at lower elevations than at upper elevations.  

This is happening already.  Schilling et al. (2026) recently used satellite data to examine long-term (1980–2024) and short-term (1999–2024) trends in the percentage of Nordic resort trail kilometers that lie above the snow-line elevation.  Below are the results for the late season (March and April) and full season (November to April).  Circles indicate the long term trend, diamonds the short-term trend, and orange fill indicates that the trends are statistically significant at a 95% confidence level.  Elevation along the x-axis is based on the resort mean elevation.  Long- and short-term trends in the percentage of Nordic resort trail kilometers during the late season are either flat or negative at nearly every resort.  Seasonal trends are also flat or negative at all but a few resorts.  Declines vary by resort, but the largest are generally at lower elevations.

Source: Schilling et al. (2026)

Geographically, large regions with negative trends  in the southwestern Alps of France and Italy and the southeastern Alps of Italy (e.g., Dolomites, etc.).  

Source: Schilling et al. (2026)

For the full season, the average trend was a decline of 1.1% per year in the percentage of Nordic resort trail kilometers above the snow line.  

There are some limitations to this study given it's use of satellite data back to 1979 when overpasses were somewhat infrequent, but in general these results are consistent with what is seen in directly measured snow cover trends from the Alps, with declines in seasonal snow cover duration largest at lower elevations.  

Much like Alpine skiing, Nordic resorts at higher elevations will have a competitive advantage for in the future due to smaller declines in natural snowpack.  This would include places like Alpe di Suisi/Seiser Alm in the Dolomites (around 1800 meters) or the Engadin Valley in Switzerland (also near 1800 meters).  That said, the demands of cross country skiing are such that high elevation is not something that many Nordic skiers might want to do, especially those who live nearer to sea level. 

Snowmaking and farming are becoming more common at some Nordic ski resorts.  On the Seefelder plateau, about 20 km of trail can be covered with artificial snow in Seefeld and another 6 km in Leutasch.  More expansion of such efforts is probably essential in the future at many resorts.  In Utah, Soldier Hollow is now experimenting with snow storage under geotextile fabrics to save snow through the summer for the next season.  

There is still time to save Nordic skiing, but it will require reducing carbon emissions and limiting future global warming.  

Temporary Halt of the Dismantling of NCAR

The National Center for Atmospheric Research Mesa Lab.  Source: Aaron Seltzer/Getty Images.

Earlier this year, the Trump administration moved to dismantle the National Center for Atmospheric Research (NCAR). One component of that dismantling was temporarily halted earlier this week by a Federal judge in Colorado.    

NCAR is run by the University Corporation for Atmospheric Research (UCAR), which was founded in 1959 and is a non-profit consortium involving more than 100 institutions of higher education.  In February, the National Science Foundation (under the direction of the Trump Administration) informed UCAR that it would transfer management and operations of the NCAR-Wyoming Supercomputer Center (NWSC) to a third-party operator.  UCAR's lawsuit argued this was a violation of federal law.  The temporary halt was imposed by after the Federal judge in Colorado decided that the transfer was arbitrary and capricious. More information is available at https://eos.org/research-and-developments/judge-blocks-nsf-from-dismantling. 

This is, however, a temporary reprieve and efforts to dismantle NCAR by the Trump administration will continue.  Real damage is being done to atmospheric science (and American science in general) by these and other actions by the Trump administration. 

NCAR is undoubtably the leading center for atmospheric research in the world.  Other major centers, like the European Center for Medium Range Weather Forecasting (ECMWF), Met Office Hadley Center, or Max Plank Institute for Meteorology have more focused missions and lack the breadth of NCAR.  NCAR also has strong ties to universities and provides important collaboration, education, and training opportunities for University faculty and students.  

NCAR has been an important thread through my entire career.  As a graduate student, I began to work with an atmospheric modeling system that was jointly developed by NCAR and Penn State University.  This modeling system, known as MM4, eventually became the MM5, which was ultimately replaced by what we know today as the Weather Research and Forecasting model (WRF).  In the early 1990s, there were only a handful of MM4 users, but by 2021 there were almost 60,000 registered users of WRF.  It is used for operational forecasting (e.g., the HRRR is based on WRF), simulations of historical events to enable diagnostic calculations or sensitivity studies not possible with observations alone, and regional climate simulations.  Many private sector companies use WRF.  

I have also been involved in field campaigns that have used NCAR's observing systems and field program support services.  The observing systems include heavily heavily instrumented Gulfstream G-V and C-130 aircraft, a polarimetric radar facility, and a variety of surface-based atmospheric sounding and profiling systems.  NCAR is vitally important for field campaign management, which can be highly complex involving in some cases hundreds of scientists and students spanning institutions not just in the United States but often in many countries (and field campaigns are often international in nature and NCAR serves a critical role here as well).  

I don't know how we got to a place where we are talking about dismantling a critical facility for the future of the Nation and humanity, but here we are.  Given the impacts of weather-related disasters in the US, we should be investing in NCAR rather than tearing it down.  Building weather and climate resiliency requires advanced knowledge and cutting-edge modeling tools.  NCAR is a wise investment for a country that experiences the greatest diversity of high-impact weather in the world and a planet that is in the early stages of abrupt and rapid climate change.  

Give Me a Reason to Come Home

I haven't enjoyed hiking like this in many years.  So many mountains in the eastern Alps and so little time.  Austria is truly an amazing place.  

With our time here winding down we're on the 2-3 hike per week schedule, including excursions near Innsbruck or right from our apartment when time is tight.  

Last Friday I did a hike up the Niederer Burgstall, a 2400 m peak in the Stubai Alps just a 35 minute bus ride from Innsbruck.  The terrain here reaches to near 3200 meters and the views are spectacular.   

A view from my descent of the the lower Stubaital and a famous local peak known as Serles just  left of center.  

Over the weekend we did a short hike from our apartment to a the Raschbrunnen mountain hut.  

Return to Innsbruck is easy.  One option is to catch the train at the Kranebitten bahnhof. 

The other is to walk a couple hundred meters down the hill and catch the K bus, which we did.  It dropped us off 3 blocks from our apartment.  This is a great way to do point-to-point hikes.

Today (Thursday) was another holiday here.  Spring in Austria is one holiday after another.  These people know how to live.  We did a hike in the Karwendel Alps east of Innsbruck to the summit of the Stanser Joch at a bit over 2000 meters.  I love this kind of ridge hiking. 

A crown jewel of the area is the Achensee, a beutiful turquoise lake that sits in a saddle between the Inn Valley to the south (and out of view to the right of the photo) and Germany to the north.  

The Achensee features industrial-scale tourism, from the many guest houses to the small cruise ships that provide short excursions on the lake.  Still, it's a pretty place.  

It's going to be hard to leave.

RRFS and Utah Snow Ensemble Repairs

Both the RRFS and Utah Snow Ensemble have been down for a few weeks on weather.utah.edu.  These outages were due to changes in the formatting of model data provided the National Weather Service and ECMWF.  I didn't have the time to dig fully into it until today and at this point I think I've got things repaired.  We will see if the automatic processing works as we move forward.  

I noticed there are a few members of the Utah Snow Ensemble producing snow at Alta Collins in several days.  

There's always hope lol.  

Media Coverage of Our SLR Work

Our work to improve forecasts of snow-to-liquid ratio (SLR) and snowfall was recently featured in a deep-dive article by Mitch Tobin of The Water Desk, an initiative of the Center for Environmental Journalism at the University of Colorado Boulder.  Peter Veals and Michael Pletcher really led this work and we benefited from collaborations with others from NOAA, the NOAA/National Weather Service and Community Collaborative Rain, Hail, and Snow Network.  And a huge shout out for everyone who provided SLR observations.  

You can access the article at https://waterdesk.org/2026/05/machine-learning-snow-to-liquid-ratio/. 

Four Hikes in Four Days

The area around Innsbruck is a hikers paradise for anyone of any age and fitness.  You can do enormous vertical if you are so inclined, hiking right from town, or cable car assisted hikes focused on alpine meadows or peak hopping.  The public transit and cable cars make access easy.  Forget the driving.  Even the buses have amazing views.  

Over the past four days I did four cable-car assisted hikes illustrating the great diversity of the region. None of these hikes were arduous or long, but they provided great views and experiences.  Below I've circled the cable cars I used to access the higher elevations.  

On day 1 I did a hike on the Nordkette immediately above Innsbruck.  I summarized this hike in the previous post (see Hike to Brandjochboden), but will add here that the Nordkette is the most accessible Alpine hiking you can do from Innsbruck.  The Nordkettenbahn consists of a funicular and two cable cars that take you from old town at 574 meters to the Nordkette ridge at 2269 meters.  There is great hiking at all elevations along this lift system, not to mention a number of mountiain huts along the way.  

On day 2 I took the J-bus from Innsbruck to the bottom of the Patscherkofelbahn, a gondola that runs to about 2000 meters.  From there, I did a short hike with a friend (and University of Utah graduate!) to the summit of the Patscherkofel, which offers up great views of the Inn Valley, Stubai Alps, and Tux Alps.  The photo below is toward the Stubai Alps with many 3000 meter peaks.  

There is a nice north-facing forest on the Patscherkofel, and several high-quality mountain huts.  In the past, I've hiked from summit to top.  It is also possible to do a point-to-point hike along the "Zirbenweg" trail to the Glungezer ski area, returning by the cable car and bus there.  One can do a variant on the Zirbenweg that goes to the summit of Glungezer at over 2600 meters.  

On day 3 I took the S4 regional train from Innsbruck to Seefeld.  This is a spectacular 35 minute train ride along a steep south facing aspect with drop-off views of the Inn Valley.  Once in Seefeld, it is about a kilometer or so walk to the Rosshütte bergbahn system that provides a lot of hiking options at elevations up to a bit over 2000 meters.  I did a short hike on this day to the Seefeld Spitze as I was going to be covering a lot of ground in Innsbruck that afternoon.  The photo below is of the Reither Spitze.  

And finally on day 4 I took the Stubaital (STB) light rail line to Mutters.  After a short walk I got on the Muttereralmbahn and did a great little loop hike below the north face of Saile (also known as Nockspitze), a prominent peak southwest of Innsbruck.  There are all sorts of hikes and scrambles you could do in this area, linking into the Kalkkogel Alps pictured below and possibly linking into the Axamer Lizum area where there are more cable cars and a bus return to Innsbruck (Axamer Lizum sits at the base of the Kalkkogel Alps).  

My route tagged a couple of minor summits with great views of the Inn Valley, which was a bit hazy today given the European heat wave (max temperature of 33C/91F in Innsbruck this afternoon).  

All of this is accessible with public transit right from town with no transfers.  The cable cars are optional, but appreciated as I get longer in the tooth.  Avoiding long descents is appreciated, but given the current heat, it's nice to start at around 2000 meters instead of 600.  

There are few useful apps for planning hikes in the area.  bergfex.com probably has the best maps and tons of route descriptions.  Hiking trails in the Innsbruck area (and maybe elsewhere) are rated on the Swiss Alpine Club scale (e.g., T1, T2, T3, etc...).  This is really helpful especially if you don't like exposure or scary scree crossings.  bergfex.com also has excellent maps, although subscription is helpful for detailed route finding using a phone.  https://maps.innsbruck.info/ is very useful for finding mountian huts (and always check if they are open, especially midweek).  

For transit, I use a combination of Google maps, Öbb Tickets, and IVB Tickets.  For buses and trains, Öbb Tickets will sell you anything you need and give you the QR code for validation if requested (common on trains, less so on buses or light-rail in Innsbruck but you should have it).  You can buy weekly all Tirol transit passes on it too.   

Hike to the Brandjochboden

It's a beautiful long weekend here in Innsbruck (we get Monday off too).  I took the opportunity today to hike from the top of the Seegrubenbahn cable car to small, 2000 meter plateau known as the Brandjochboden.  The route traversed below the crest of the Nordkette, the main ridge that rises above the Inn Valley near Innsbruck, offering non-stop views.  Below I've highlighted the first mile or so of the route from Seebrube, which is hidden in this photo but near the start of the arrow.

The morning began with just a bit of haze and pollution in the Inn Valley.  This is not all that unusual as it either sneaks in from Germany or Italy or is produced by the enormous amount of traffic that flows through the Inn Valley between Germany and Italy.  

Such pollution is usually most apparent when looking toward the morning sun.  This is a result of what is known as forward scattering of sunlight, perhaps a topic for a future post.  The views in other directions were stellar.  The phto below is looking toward the west southwest and includes Innsbruck, the Wipp Valley which ascdends into the Alps on the west side of the photo, ultimately leading to the Brenner Pass and Italy, and the Stubai Alps, including snow covered "Habicht", the 3277 m high mountain on the horizin near the center of the photo.  

Surprisingly few people were hiking today.  I think I saw a total of six or seven people once I left the Seebrubenbahn.  There were far more sheep including this flock.  

The Brandsjochboden is a flat, peaceful place.  I suspect in a few weeks it will be covered with the green high-Alpine carpet for which Austria is famous.  The grasses haven't awoken yet at this elevation, but the views were still fantastic.  Below are the Stubai Alps, with the Sellrain Valley entering them on the right side of the photo.  There's a lot of spectacular mountains to the north of the Sellrain Valley and some great ski touring.  

After returning to Seegrube, I took the Hafelekar cable car up to the top of the Nordkette, which provided a good perspective on the hike.  I began at Seegrube and ended at the Brandjochboden, which is roughly where the arrow is.  There is about 2000 m (7000 ft) of relief here from the Inn Valley to the top of the Brandjochspitze.  

BTW, if you are in Innsbruck and only have time for one hike, don't do the one described above.  It's fun, but no where near as great as the Goetheweg, the start of which I've identified in the photo above.  The Goetheweg begins at the top of the Hafelekar cable car and traverses along the Nordkette as it goes eastward to the Pfeissehutte mountain hut.  It's a much better trail, and spends time on both sides of the Nordkette, with some unbelievable views.  Below is a photo from our last trip here to whet your appetite.

Memorial Day Weekend Outlook

Watching from a distance, the official start of summer/Memorial Day Outlook is generally looking good for Utah.  For the most part it looks nice, with above average temperatures, although the models are hinting at a chance of some afternoon or evening showers and maybe even a scattered thunderstorm mainly over the high terrain over the weekend.  One example is below, which is the ECMWF forecast for 2100 UTC (3 PM MDT) Sunday 24 May with some showers over the Uintas, Tavaputs Plateau, and high terrain in southern Utah.  

Models vary on the where and the when and so it's just worth keeping an eye on the forecasts and the sky when recreating.  

Enjoy the long weekend.  

May Snow

 I see that a return of colder weather and mountain snow is in the forecast for northern Utah.

Downloaded from NWS Salt Lake City web site at 0840 MDT Sunday 17 May 2026

We just had a round of cold weather and snow here in Innsbruck too.  We could have used it in March, but it does create some nice scenery.

It almost looked like winter at the top of the Patscherkofel gondola today.  Pretty good coverage on the upper slopes thanks to a few inches of high-density fresh.  

Snow is confined to the upper third of the mountain, but I did see someone booting up at the top of the gondola.  I can only assume they were going to skin up the access road that goes to the top of the mountain as going down would take you to the snow line in no time. 

There are several mountain huts on the Patscherkofel.  Along with gondola access, you can opt to do anything from short to long hikes to these huts.  All ages are on the mountain for this reason.  Near the top of the gondola, the Schutzhaus is worth a stop if you've hiked up from the bottom.  

I opted for strudle and a hot tea today.  

And here's a pro tip for hiking in the Alps when you are using public transit.  Always leave a little in the tank in case you have to do more walking.  On my return bus home, an announcement was made as we got into town that they would not be able to complete the service.  Instead of getting dropped off near our flat, I got dropped off about a 25 minute walk away.  Turns out there was a parade in the old town.  

Turns out this was the 28th Alpine Region Meeting of Riflemen from Tyrol, South Tyrol, Trentino and Bavaria.  Who knew?  

These guys have all the tools to run the outlaws out of the village.  

It was a nice cultural surprise.  

RRFS to Become Operational August 31, 2026

The Rapid Refresh Forecast System (RRFS) and RRFS Ensemble Forecast System (REFS) is scheduled to become operational with the 1200 UTC run on August 31, 2026.  The RRFS ensemble has been intermittently available on weather.utah.edu now for a couple of years (yes, I know it hasn't been available in a few weeks).  It's been a long slog for the National Weather Service to get the RRFS operational, so let's hope this proves to be a productive upgrade.

The RRFS and REFS will replace the NAM, HREF, SREF, and HiresW operational modling systems, if you happen to use those.  These will all be retired on the same day the RRFS and REFS become operational, along with their derived products.  I won't be sad to see any of these go.  

As is often the case, they have made the acronyms and ensemble model configurations as complicated as possible.  The so-called deterministic RRFS will run out to 18 hours hourly and out to 84 hours for the 0000, 0600, 1200, and 1800 UTC cycles.  It will cover the North America, including Alaska, at 3 km grid spacing.  There will also be a relocatable 1.5 km fire weather run. 

The RRFS will also produce forecasts from five ensemble members out to 60 hours for the 0000, 0600, 1200, and 1800 UTC cycles.  These members will involve a mix of differing initial conditions, lateral boundary conditions, and model physics.  The REFS is based on a combination of the deterministic and five ensemble members from the most recent and prior RRFS runs.  It is thus a time-lagged ensemble.  

I'm not sure to what degree I'll use the time-lagged REFS or its products.  I may stick with the six-member "RRFS ensemble" as we have been doing just because it is easier and I lack the time and mind to deal with complex things.  

The full announcent is available at https://www.weather.gov/media/notification/pdf_2026/scn26-48_RRFS_and_REFS_Implementation.pdf, if you are interested in some of the details.  

As I mentioned, I hope this upgrade proves productive.  The RRFS development has had many problems and is greatly delayed.  My time in Austria, with access to many modeling systems and ensembles that are run at higher resolution and with more members than the RRFS and the RRFS ensemble, has shown me that the US is now well behind Europe in operational numerical weather prediction (see I Have Seen the Future).  The RRFS won't fully close the gap to where we could be, but we will all hopefuly benefit from an advance in operational modeling capabilities.  

Convective Graupel Showers

Spring and summer mountain thunderstorms can produce precipitation that sometimes includes graupel or small hail that can penetrate well below the freezing level.  

A good example happened yesterday over the Nordkette ridge just north of Innsbruck.  I had a great view of it from my office. The storm popped up around 2 PM local time.  The streaky virga in the right of the photo below srongly suggested the presence of graupel or small hail.  A bit farther to the west (left in the photo) though was less precipitation and even a bit of sun peaking through a hole in the clouds.  

After a couple of rumbles of thunder, the storm was over quickly.  Light graupel accumulations were evident where the cell was, with accumulations reaching down to about 1900 meters, whereas the high ridge farther west, which reaches over 2300 meters, was still snow free.  

A web-cam on the portion of the ridge that received precipitation showed some graupel accumulation at 1900 meters.  

Source: https://www.foto-webcam.eu/webcam/innsbruck/

It didn't take long for the graupel to melt once the storm was over, but it was good entertainment while it lasted. 

I Have Seen the Future

One of the great things about coming to Europe to work is getting exposed to the latest and greatest modeling systems for operational weather prediction.  

Modeling systems for operational weather prediction in the United States has stagnated now for several years.  The last major upgrade was when the Global Forecast System (GFS) upgraded to the Finite–Volume Cubed Sphere (FV3) dynamical core in 2021.  Beyond that, upgrades have been  incremental, with no major changes to the grid spacing of the GFS (13-km) or the HRRR (3-km).  The GFS Ensemble (GEFS), Short-Range Ensemble Forecast System (SREF), and High Resolution Ensemble Forecast system (HREF) have aged and are no longer cutting edge. 

Meanwhile in Europe, both numerical and artificial intelligence weather prediction systems (NWP and AIWP respectively) are advancing rapidly.  Readers of this blog are likely well aware that the European Center for Medium-range Weather Forecasting (ECMWF) ensemble has the highest resolution (9 km), most members (51), best data assimilation, and best statistical performance of any operational, global, numerical modeling system in the world.  ECMWF is also also at the forefront of AIWP and now has their Artificial Intelligence Forecast System (AIFS) ensemble running four times a day.  

But European countries are also pushing the frontiers of limited-area modeling systems that forecast for a specific region.  For example, Meteo Swiss runs an operational, 11-member, 1-km ensemble eight times a day with forecasts out to 33 hours.  They also run a 21-member, 2.1-km ensemble four times a day with forecasts out to 120 hours (see https://www.meteoswiss.admin.ch/weather/warning-and-forecasting-systems/icon-forecasting-systems.html). These forecasts are produced using the ICON model, which was originally developed at the Max Planck Institute for Meteorology in Germany.  The ICON is also used by the German Weather Service.

Here at the University of Innsbruck, I have access to an experimental version of the ICON model run by the Deutscher Wetterdienst (DWD; German Weather Service) at 500-meter grid spacing.  NWP models run at such grid spacings are sometimes called large-eddy simulations (LES) rather than mesoscale simulations because they are beginning to resolve the large eddies that are found in the boundary layer, the portion of the atmosphere that interacts directly with the Earth's surface.  A model run at 500-meter grid spacing also better resolves the fine-scale terrain in mountains regions, which is particularly important in the Alps where glacier-carved mountain valleys are quite narrow.  

Let's look at last night's 6-hour forecast from the 500-m ICON valid at 0600 UTC or 8 AM local time this morning.  The plot below shows the wind (vectors with color fill for speed in meters per second) at 2000 m elevation (relative to sea level).  Terrain elevation above 2000 m is indicated by grey shading. The pattern is characteristic of what are known here as föhn, a strong wind that affects the northern Alps during southerly flow.  In the Innsbruck area, the föhn acclerates as it moves northward through Brenner Pass and down the Wipp Valley.  At this 2000 m elevation, that strong flow eventually moves over Innsbruck and encounters the Karwendel Alps, leading to flow splitting on their southern (windward) side and a wake on their northern (leeward) side.  Locally strong föhn can also be seen in and north of other Alpine Valleys in the region.  

Source: University of Innsbruck

A cross-section from the ICON taken from south (left) to north (right) down the Inn Valley illustrates the vertical structure of the föhn in this forecast.  Locations identified in the cross section include Brenner Pass (BRE) and Innsbruck (IBK).  Note in particular that the strongest föhn flow becomes elevated just upstream of Innsbruck (near EUR) and ultimately rises rapidly whe it encounters the Nordkette ridge of the Karwendal Alps to the north of Innsbruck.  

Source: University of Innsbruck

The cause for the detatchment of the föhn flow from the surface as it approaches Innsbruck is the formation of a nighttime old pool over the Inn Valley.  At night and in the morning, the föhn often rises over this cold pool, although there are times it can "break into" the cold pool, resulting in strong south winds at the surface in Innsbruck.  This is an important forecast problem for the region, including for the local airport, as it affects runway flow direction and the elevation of föhn related turbulence.

How did that forecast verify?  Quite well.  Below is a time-height section of winds over Innsbruck observed with a wind lidar.  The time-height section is for a 24-hour period (time increases to the right).  I've added a red line corresponding to the time of the forecast above.  Note how in the left half of the diagram, the föhn frequently extended to the ground.  Then, just prior to and after 0000 UTC (0200 local time), winds over Innsbruck weakened.  However, by 0600 UTC the southerlies aloft increased once again, resulting in a structure similar to that above with light flow at low levels but strong flow aloft.  

Source: University of Innsbruck

Readers of this blog with a strong interest in snow might also be interested in seeing the corresponding 500-m precipitation forecast.  Validating this is a bit more difficult given the poor radar coverage in the Alps, so I provide it simply for entertainment purposes.  

Source: University of Innsbruck

Enjoy a look at the future.

Walking

This is my second long-term visit to Innsbruck and in both cases my body went through a real transformation due to the amount of walking that one does here.  I would guess that I average walking 10 km a day, scattered around from morning to night.  It's a great way to keep the body in motion.  

And Innsbruck is a wonderful place to walk.  The town in interesting and many places historical.  There are views everywhere.  The old town area is car free, but even elsewhere, the road traffic is moving slowly and respectfully.  Just look at a crosswalk and drivers will stop.  Austrian law is very protective of pedestrians, but drivers here are also very pedestrian aware because everyone here walks some.  

One can also hike right from town, accessing mountain huts on the Nordkette north of town or if you are so inclined, ascending all the way to the ridgeline about 2000 meters above town.  Public transit is exceptional so one can access hikes in the surrounding region easily or use public transit to enable one way hikes with a bus return.  Believe me when I say that high-quality summertime public transit would completely transform recreation in the central Wasatch by enabling many outstanding point-to-point through hikes. 

One of my favorite destinations for a casual walk or hike is the Hungerburg neighborhood that sits on a ledge about 300 meters above Innsbruck.  I get a nice little climb in when I go there taking any number of routes.  There is the direct route following cobbled roads, pedestrian paths, and trails, which takes about 45 minutes, or more circuitous options involving urban walking and trail hiking that might take an hour or two.  I just go with what feels right and return via bus or funicular.

The route I did today merges the best of everything.  It starts with a level section along the Inn River.  I realize seeing this river every day how much I miss water living in Utah.  

Then there's about a 300 vertical meter ascent through managed forests that occaisionally open up for a quick view.

Once at Hungerburg, there's a wonderful view of Innsbruck.    

I often return to the valley floor via the Hungerburgbahn funicular.  Below is the entrance.  A walk up ticket is an overly expensive 7 euro, but fortunately I get unlimited free access with my ski pass.  

One reason I like to return via the funicular is that it ends near the Innsbruck Old Town and I enjoy walking through it to get back to our apartment, especially in the morning when there are no crowds.

There is a gelateria that is open early if one is inclined to have ice cream for breakfast.  I showed great will power not stopping this morning, although I ultimately had a schokomuffin while walking to the office.  So many bakeries.  So little time.