Wasatch Weather Weenies

Yesterday (Saturday) was the opening day for ski season for me with a warm up lap up Collins Gulch at Alta to shake off the rust and see what needs to be fixed or replaced.   There were a few people that had the same idea as me.   And plenty of entertainment to be had.  Look carefully and you can see the 22-degree halo.   One change on the Mt. Baldy skyline is the addition of Wyssen Tower Avalanche Control Systems.   I find their presence on Mt. Baldy unsightly, but understand why Alta is moving to them as they attempt to reduce and sunset the use of the 105 mm Howitzer, which has enormous risks.   If you haven't seen these towers in action, here's a video. I'm not sure if these are UDOT's, Alta's, or some combination of both, but the deployment boxes for the Wyssen Towers and O'bellx pods were sitting in the Wildcat lot just ready to be loaded and then flown in by helicopter.   A lot happens so you can go skiing on a powd...

We're off to a good start for October, although conditions are not "All Time."  The Snowbird SNOTEL record begins in 1990, so the discussion below is only of the recent history since then.  The current (October 29) snowpack water equivalent at that site is 3.9" (black line).  That rates as the third highest on that date since 1990, topped only by the 2005 and 2022 water years.  Other water years close to this one are 2011 and 2020.   Source: NRCS "All Time" since 1990 is undoubtably October 2004 (plotted above as the 2005 water year), which had an October 31 snowpack water equivalent of 10.8".  The Halloween lake-effect storm that laid down 2 feet of cold smoke on an already quite healthy early-season snowpack that October created epic backcountry skiing conditions that some of the Wasatch backcountry cognoscenti ultimately rated the best of the year.  Since 1990, October 2004 is undoubtably the gold standard for early season powder skiing.  ...

After a dry spell for the rest of October, a deep upper-level trough is expected to develop along the west coast of the US.  We can be reasonably confident of that, but the details of its amplitude, movement, and accompanying precipitation features are still very murky and uncertain.  As a result, the North American Ensemble Forecast System (NAEFS) plume for Alta Collins is a big mess of spaghetti for November 2nd and 3rd with a range from 0 to 2.4 inches of water and 0 to 40 inches of snow.   If you want good news, about half of the members produce more than 10 inches of snow.  If you want bad news, about half are less than that (through 0000 UTC 4 November).  The various ensemble members have not converged around a favored solution. In a couple of days, perhaps they will.  For example, forecasts for the storm last weekend also exhibited a great deal of spread when the storm was about 5-7 days out.   However, they began to cluster and give i...

The storm yesterday and last night added another 8" of new snow and .65" of water at the Alta-Collins site bringing the total snow depth up to 27." These are solid numbers for late October and I hope to get out and make some turns soon.   Other than maybe a few more flurries this morning, the forecast looks dry for the next few days as we return to more fall-like weather with the storm track to the north.  The NAEFS plumes below are flatlined between last nights storm and November 2nd when a few members begin to show some action.   At that time, the GFS and many other models or ensemble forecast members are advertising a deep trough to develop over the Pacific Coast.   Until then, enjoy the return to fall weather, make a few turns, do some rescue practice, and hope the spigot turns on again in early November.

Effective with the 1200 UTC 24 October GFS run, the GFS-derived Little Cottonwood forecast guidance product on weather.utah.edu (direct link:  https://www.inscc.utah.edu/~steenburgh/ml/lccforecast.html ) has been updated with new equations for forecasting key variables.   Specifically, the Mt. Baldy wind, temperature, and dewpoint forecast guidance now includes another cool season (2021/22) for training and the snow-to-liquid ratio (and derived snowfall amount) uses a new algorithm that includes data from multiple western U.S. snow safety sites.  I expect these changes to make small improvements in accuracy, with the snow-to-liquid ratio exhibiting more dependence on wind speed.  The guidance also goes to 180 hours and the data feed we are using should be faster and more reliable than what we used last year.   Below is the guidance from last night's 6Z GFS.   Enjoy, and remember this is forecast guidance, not an official forecast.  Consu...

The weekend storm was a good one for October with the Collins gauge recording about 2.66"of water and 25" of snow if my interpretation of the data is correct. I didn't try to ski yesterday, but noticed a well-formed conga line heading up Corkscrew each time I took a look at the Alta web cams.   The question now is whether or not this will continue, building up a stable snowpack for the coming ski season, or whether or not the ridge will return, resulting in the development of a persistent weak layer (PWL) on north aspects. Forecasts for the next week at least suggest we will have some chances to add to the snowpack.  The first is tonight and early tomorrow when a weak upper-level trough and cold front move through.   The next is Wednesday and Wednesday night when another upper-level trough and cold front are forecast to move through.  This one is a bit stronger.   From these two storms, the GFS generates about 0.9" of water and 13" of snow. This i...

Yesterday's storm delivered.  Total snow depth at Alta Collins now sits at 17" with 2.08" of water falling through 6 AM.   Source: MesoWest Things pretty much exploded yesterday with a surprise pre-frontal band moving through in the morning and then the front in the afternoon, with peak snowfall rates near 3 inches an hour and SWE rates of 0.34.  This first part of the storm brought some really high-density snow, which is just what we need to start the season.  Overnight, densities have dropped as have snowfall and precipitation rates.  There were even a few breaks. The situation overnight ended up proving that in the post-frontal environment, there are a lot of "critters in the woods" with plenty going on.  Sure, some cells bubbling up over the lake, but also over the west desert and to the northeast of the lake.  Hopefully this will show up well in the loop below.  I never know what blogger is going to do with .mov files.   At the...

The south wind is roaring at my house right now in advance of a cold front that has been anticipated for days and is already moving quickly into northern Utah.   As of 1311 UUTC (711 MDT) this morning, radar echoes were covering portions of northwest Utah.   It's going to be an exciting day and weekend! This morning I woke up not wondering what will happen in the mountains, but what will happen in the valleys and on the benches.  Heavy snowfall looks to be a lead-pipe cinch in the northern Wasatch with the National Weather Service calling for widespread 8-18" and up to 24" of snow.   However, the potential for snow also exists for the valleys and the benches, but the timing, locations, and amounts are unclear. Below is the GFS time-height section for Salt Lake City.  After today's frontal passage, we enter a long period, roughly 36-48 hours, of cold, moist, unstable, post-frontal flow.   This means mountain snow showers, but also the pot...

Forecasts for the weekend storm are pretty locked in and I think there's about a 50% chance that there will be enough snow to ski at Alta on Monday.   For that forecast, I'm assuming that 2" of snowfall water equivalent (SWE) is the minimum needed for skiing the main run down Collins Gulch.  Some might go with less than that, but historically that's my bare minimum.  As discussed previously, the remainder of the work week looks dry and pleasant.  The 0600 UTC initialized GFS brings the much anticipated cold front into Utah during the day on Saturday and at 0000 UTC 23 October (6 PM MDT Saturday) widespread frontal precipitation covers the Salt Lake Valley and central and northern Wasatch.   It's a slow moving frontal system and by 1200 UTC 23 October (6 AM MDT Sunday), the 700-mb (roughly 10,000 ft) trough axis has only progressed into central Utah.  If we are fortunate, this will give us several hours of frontal precipitation. During the day on S...

This isn't exactly breaking news, but change is coming in the form of a cold front this weekend.   Until then, we will have a splendid run of dry, fall weather.  Ideal for mountain biking or hiking if you can get out.  The situation this morning is characterized by a strong, high-amplitude ridge centered over central Idaho.   This ridge will weaken during the work week, but we should see mainly sunny weather through at least Thursday.  On Friday, there may be a few high clouds, but no biggie. During the weekend, an upper-level trough digs into the western United States.  The latest GFS forecast below shows the associated cold front over northern Utah at 0000 UTC 23 October (6 PM MDT Saturday).   The GFS time height section shows very low humidities over Utah and wonderful fall weather through Friday morning (a reminder that time increases to the left in the plot below).  Some higher humidity air moves in aloft ahead of the front whi...

For the first time in many years, my teaching schedule allowed me to travel over a two-week period in early October, including last week's spring break.  Andrea and I had not returned to Innsbruck since we lived there during my sabbatical in 2019 and we wanted to see friends there.  We also thought it might be a good time of year to visit the Jungfrau of Switzerland, which is the focus of this post. I've wanted to visit the Jungfrau since reading Jon Krakauer's Eiger Dreams .  Watching the Lauberhorn Downhill and its incredible mountain backdrops, also increased the stoke.  The Jungfrau region lies south of Interlaken, Switzerland and includes the Junfrau Massif (consisting of the Eiger, Mönch, and Jungfrau), the Lauterbrunnen Valley, the Grindelwald Valley, and the villages of Grindelwald, Wengen, Lauterbrunnen, and Mürren amongst many other peaks, valleys, and villages.  I found it to be the Land of the Impossible due to the impossible relief, impossible mount...

Taking some down time for a couple of weeks.  See everyone in mid October.  Maybe there will be hope for snow by then.  Until then, begin with a few slow breaths, in through your nose and out through your mouth.  Let your body relax.  Visualize snowy mountains.  Imagine skiing deep powder.  Do this several times a day.