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.