Wasatch Weather Weenies

It's impossible to know when we will have the season's last powder day, but if today was it, that's OK.   With perhaps 15-20 cm of new snow, Room of Doom in upper Mineral Fork was ours this morning.  One could feel the stout melt-freeze crust at times, but the skiing was still fun.   Given our fair snowpack conditions, this storm was desperately needed.  We need more, but every little bit helps.  Some of the moisture from this most recent snow will evaporate into the atmosphere.  Some of it will be used by plants.  Some of it will recharge our soils, which are remarkably dry.  And some of it will enter Big Cottonwood Creek and provide the water we all need for taking showers, flushing toilets, and watering gardens.  Thus, it is not a stretch to say that April powder brings June flowers, at least in this part of Utah.   The view below from the top of our climb shows the upper reaches of the vast Mill-B South drainage, also ...

Yesterday we tied a record for April 4 with a maximum temperature of 79˚F at the Salt Lake City International Airport.  Impacts on snow aside, the weather was about as delightful as it could be in early April.  It's a bit of a shame we can't bottle up a day like that and open it up in mid July.   It was very warm in the mountains as well with Alta setting a new maximum temperature record of 58˚F.   The heat has done its damage as several SNOTEL sites have seen declines in snowpack snow water equivalent, despite their relatively protected locations, indicating that the snowpack has ripened and begun to decline to melt.  Parley's Summit SNOTEL, which is on a north aspect, dropped from 15 inches on April 1st to 12.2 inches last night.   Source: NRCS Even upper-elevation Brighton saw a decrease in snow water equivalent.  This site is a bit sunnier than most SNOTELs, but this is a substantial drop for early April.   That all ends af...

 In recent years, a wiggle (or snake) has appeared at Alta or Snowbird.   Photo of the Day | 4.3.2021 The wiggle has transformed Ballroom this spring. Have you wiggled this spring? 📸: @rockomenzyk https://t.co/MRJ6yOl9lG pic.twitter.com/FXgzM89usV — Alta Ski Area (@AltaSkiArea) April 3, 2021 Some get excited about these slope enhancements, but not me.   During my sabbatical in Innsbruck, I encountered figl skiing, or figln (see Tirolean Figln ).  Figln becomes a thing in April at Nordkette ski resort above Innsbruck in April and involves the use of short skis to go downhill, using the tails to control speed.  As I understand it, the history of figln derives from mountaineering as the light, short skis could be used to quickly descend remarkably steep slopes back in the day.  The Nordkette has ideal conditions for Figln as it is steep (especially off the upper Hafelekar Tram) and south facing.   Here's a video demo.  Start at abo...

April 1st is near the time of peak snowpack for many Utah SNOTEL stations.  On average, lower elevations peak earlier than this, whereas upper elevations peak later, but April 1 is traditionally a good date for getting an idea of how fat the snowpack is for the spring runoff. This year's April 1 snowpack is no joke, with the vast majority of stations below median (note the plots below are technically through March 31). To show this, below is a plot of the percentile snow water equivalent.  This percentile represents that percentage of previous seasons in the period of record with a lower snowpack snow water equivalent (SWE) than current.  A value of 25 means that 25% of the seasons have less (SWE), whereas 75% have more.  The higher the percentile, fatter the snowpack compared to past seasons.  Many Utah SNOTEL stations are at or below 37.5, some well below.  A handful are near or above 50.  This includes sites in the northeast Uintas, and scattered ab...

Yesterday's cold-frontal passage probably brought more dust to the central Wasatch than snow.  Frontal passage at the University of Utah featured the usual wind shift and temperature drop, but also a spike in PM2.5 associated with blowing dust. Peak concentrations at the U reached almost 15 ug/m3, which equates to a moderate air quality level.   Cameras at the University of Utah caught the post-frontal dust and gravity-current-like nose of the cold front passing through the Salt Lake Valley. Post-frontal dust and gravity-current-like nose of cold front that just passed through Salt Lake shows up well in this video. Watch carefully for the moonset too. pic.twitter.com/qr27dhAiu8 — Jim Steenburgh (@ProfessorPowder) March 29, 2021 And check out the terrain induced flows over western Nevada with dust from the Carson Sink providing a great tracer.  Large dust storm pushing south through the Nevada desert towards the California border. @NWSReno #NVwx pic.twitter.com/aYd...

I hope you enjoyed the cooler and somewhat snowier weather over the past week as it appears that things will be changing moving forward.   Over the past week, I finally got out and got some ski touring in and enjoyed skiing powder again.  Yesterday provided a weather potpourri of low visibility and occasional snow and graupel showers with the cloud over acting to preserve the powder through the day (thankfully).   The graupel was generally light, but during one heavier period, we were treated to graupelfalls over some of the cliffs where we were touring.   The snow over the past week on upper-elevation north-facing aspects survived quite well thanks to a progression of cold troughs.  Forecasts for the next week are not as optimistic.  The GFS and other models forecast a strong frontal passage Monday, but without a lot of moisture.   Thus, it will be cold, but likely a dust on crust event.  The remainder of the work week looks d...

It has not been a great snow season across Utah and southern Wyoming.  The vast majority of SNOTEL stations sit below median snowpack snow water equivalent.  Source: NRCS However, if you look carefully, there are some sites that are above average and in a few cases well above average.  In particular, check out sites along the north slope of the Uintas, over the Tavaputs Plateau in eastern Utah, and along the Laramie Mountains of eastern Wyoming.   These are sites that are relatively dry, with low median peak snow water equivalents of 15 inches or less, but got creamed during the period of the Front Range Blizzard in mid March.  One outlier event has made their whole season.   For example, Hickerson Park on the north slope of the Uinta Mountains has a low median peak snow water equivalent (< 10 inches), picked up over 4 inches of water equivalent during the Front Range Blizzard period, lifting them to median peak SWE (note that the green box is ...