Wasatch Weather Weenies

Although we didn't hit the 80˚F US unit psych point for maximum temperatures, the last three days have been blisteringly hot.   Salt Lake City area weather records begin in 1875 based on observations collected in downtown Salt Lake City prior to the 1920s and the Salt Lake City Airport thereafter.  In terms of the mean maximum temperature and average temperature, the last 3 days were the warmest on record during 1-27 March.   Source: http://xmacis.rcc-acis.org/ Source: http://xmacis.rcc-acis.org/ For minimum temperature the mean was the 2nd warmest on record, behind 1907.  1910 also had a warm 3-day period, although the observations in those years were collected in downtown Salt Lake City, not at the airport.   Source: http://xmacis.rcc-acis.org/ Additionally, thin high clouds meant net longwave cooling was limited.  I didn't bother skiing this weekend, but the Utah Avalanche Center notes this morning that most mountain locatio...

There's lots of chatter right now about the warmth this weekend and the potential of a maximum temperature at the airport of 80ºF on Saturday or Sunday.  That would be the earliest 80˚F on record.  The current first 80˚F was observed on March 31, 2012 [Note from Jim: This was corrected from 2021, which was an error].  After April 5, all days through the summer have record maxima at or above 80˚F.   To do this, we'll take a look at forecasts produced by the National Weather Service National Blend of Models, or NBM.  The NBM is a system that takes forecasts from many modeling systems, puts them together in a big ensemble, and then applies statistical techniques to yield forecasts, including those of maximum and minimum temperature at locations like the Salt Lake City international airport. The NBM forecast for the Salt Lake City airport is below.  The maximum (red) and minimum (blue) temperature forecasts for the next 10-11 days are presented in the left...

Steenburgh winter never happened this year.  Meteorological winter ended on March 1st.  Astronomical winter ended on March 20th.   However, today might have been the last day of winter at ski resorts in upper Little Cottonwood.  At least that's what we called it at Snowbird this morning where the life expectancy of chalky groomers is now no longer than a day.  For groomer, Regulator Johnson was really outstanding this morning.   Temperatures today are climbing and they will continue to do so, with the usual nighttime interruption, through the weekend.  We will se snow again in the future, but the transformation this week is going to be dramatic.  Check out the National Weather Service Forecast for the Salt Lake City International Airport.  81˚F on Saturday!  81˚F!   Source: NWS.  Downloaded 1:10PM 23 March 2022 That's insane.  The earliest 80 on record was recorded on March 31, and that was in 2012. ...

Astronomical spring began yesterday, so it is worth taking a moment to examine the snowpack situation across the west. As you may recall, we entered March with the western snowpack generally at or below median in most drainage basins.   Source: NRCS For the most part, things haven't changed much over the past 3 weeks.  Some basins have climbed a bit closer to median (e.g., southern and eastern Utah, Colorado), whereas others have lost a bit (e.g., Washington, Sierra Nevada).   Source: NRCS Northern Utah basins now sit at 80-85% of median, compared to 71–80% on 1 March.  That's good, but still concerning.  For the Jordan, which includes the central Wasatch, we now sit at 13.8" of average water equivalent at SNOTEL stations compared to a median of 16.9".  Source: NRCS However, the situation is arguably worse than that for two reasons.  First, the green line above is the median daily water equivalent.  Because of differences in the timing ...

A major multi-day Saharan dust event has ravaged the snowpack in the Alps and the air quality across parts of Europe this week. Below is a composite MODIS image from Tuesday (15 March) showing a cyclone off the coast of Morocco with extensive dust streaming northward from the Sahara across Spain and France.   If you think snirt (snow+dirt) is bad around here, check out the video below from Spain's Sierra Nevada.   Sierra Nevada pic.twitter.com/ukUhZkYud6 — Esteban Villarejo (@Villarejo) March 15, 2022 Dust coverage was extensive.  Here's a web cam from this afternoon at Mölltaler Glacier in the eastern Alps of Austria.  Saharan dust events are not uncommon in parts of Europe, but this one looks especially severe.  In addition to making for a less-than-ideal ski surface, such dust does accelerate the spring melt by increasing the amount of solar radiation absorbed by the snowpack.  On the other hand, the dust also provide nutrients for ecosystems....

I don't have much to say today.  Some periods of mountain snow beginning this evening through tomorrow.  GFS says 3" or so for Alta through Wednesday and most members of the downscaled SREF are under 2.5", although 6 of the 26 members go for 3-6.5".   Nothing to get excited about.   Footage of yesterday's skier-triggered avalanche on a run known as Barrieto in Mineral Fork is below (per reports, the skier was performing a ski cut and was able to avoid harm).  I'm not sure who to credit for the video or the photo below, but click here for the report on the Utah Avalanche Center site  I think it is the largest skier-triggered avalanche I've seen a video of from the Wasatch Backcountry. Below you can see the full path with the crown near the Mineral Fork – Lake Blanche Fork ridgeline to the toe in the bottom of Mineral Fork.   Debris covers a good portion of the Jeep/ATV road that switchbacks up through the base of the slide path and where...

Today is the last day of Nordic operations at Mountain Dell.  Although a foot injury has shut down my skating (and touring) adventures since the end of January, I felt well enough to do a short 5 K skate today.  It was great to get out on the skinny sticks again!  Additionally, given the ephemeral nature of the snowpack at Mountain Dell, coverage was quite good for the last day of the season thanks to recent storms. I thank The Utah Nordic Alliance (TUNA) and the groomers for maintaining this great community resource again this year.  We are so fortunate to have cross-country skiing a short drive from Salt Lake City.  Efforts to farm snow this year really paid off and enabled nearly continuous operations since mid December despite another poor snow season.  The closure today reflects contractural obligations with Salt Lake City and the golf course rather than lack of snow.   It's a shame they can't try for one more weekend.   Addendum @ ...

For groomers and skiing fast, days don't come much better than this morning.  We have some friends in town from back east and I'm fairly certain it was the best day of skiing they've ever had.  Other than a bit of a north wind, the snow and weather conditions were as good as you can get without powder.   Over the past few weeks, I've been Professor Piste instead of Professor Powder due to a foot and ankle injury.  Touring and Nordic skiing have been verboten, and even walking has been difficult.  I've been able to do two a little Alpine skiing on groomers though, and that has helped me keep my sanity.  It has been a stingy injury, but it improved quite a bit over the past week.  Keeping my fingers crossed that the trend is my friend.  If you see someone struggling through a 5 K skate sometime in the next week or two, that would be me. If you were up in Little Cottonwood, you may have noticed a great Asperitas cloud display.  I took the p...

Mother Nature has finally delivered a proper deep-powder day to the central Wasatch.  As of 9 am this morning, total snowfall at the Alta Collins since yesterday morning was 19 inches.  As storms go, that's about as Goldilocks as it gets.  In other words, not too big, not too small, but just right.  Additionally, this was a great storm pretty much for everyone.  Some additional reports from earlier this morning include 13 inches at Spruces (6 AM), 9.5 inches at Canyons Village/Park City (8800 ft, 9.5"), and 13 inches at Summit Park (7 AM).  For the central Wasatch, Deer Valley reported the lowest total this morning (8"), so everyone is close to my minimum threshold for a deep-powder day (10").  It's possible that the additional snow pushed everyone to that level.   For the Nordic skiers, I suspect the snowpack at Mountain Dell might be as fat as it has been all year.   Expect periods of snow in the Cottonwoods today due to unstable ...

We have a decent setup for snow on the way, one that will extend the Nordic season at Mountain Dell and maybe even provide a proper deep powder day at Alta. The GFS large-scale forecast of 500-mb geopotential height (black contours), precipitable water (color contours)m and 6-hour accumulated precipitation (color fill) for 0000 UTC 9 March (5 PM MST this afternoon) is below.  It's actually not a hell of a lot different than we've seen quite a bit over the past two months.  There is a ridge off the Pacific coast with a trough dropping down out of Canada.   However, there are a few favorable wrinkles this time.  First, there is a plume of moisture associated with a decaying atmospheric river remnant that has snuck under the ridge and is extending into the Pacific Northwest ahead of the approaching trough.  Thus, the system is not as moisture starved as many of the recent troughs.  Second, the pattern is shifted a bit farther upstream, so instead of slidi...

There aren't many days when the Avenues get the bragging rights for snowfall, but today is one of them.   During the day yesterday, a frontal boundary developed over northern Utah, with the band especially strong along the I-80 corridor from the area near Stansbury Island to the Salt Lake City International Airport and the lower avenues.  Below is the radar imagery for 02:42 UTC (7:42 PM MST) illustrating the situation.   Source: NCAR/RAL A sounding collected at the airport at just before 0000 UTC (5 PM) showed shallow northerly flow associated with the front below about 725 mb, with southeasterly flow aloft.   Source: SPC Additionally, the sounding was very moist at low levels and near what meteorologists call moist neutral , meaning that the stability was weak to non-existent or even weakly unstable for moist flows (i.e., with a relative humidity of 100%).  Thunder was even reported in some parts of the Salt Lake Valley that afternoon. ...

Most skiers and snowboarders are salivating right now at the prospects of a deep-powder day.  Snow is in the forecast and excitement is running high.   However, this is a classic patience is a virtue pattern.  Today's early action is scattered, with accumulations hit and miss and primarily consisting of high-density snow at upper elevations.  Most of the precipitation is being produced by surface heating.  You may even have heard some thunder.   The precipitation tonight is also scattered.  If you're lucky, your favorite ski area might get hit by something that is intense and moves slowly, but it might also get little.   A look the GFS shows a more organized frontal system developing Saturday night, pivoting over northern Utah, and then rotating through the area on Sunday.  Below is the GFS forecast for 1500 UTC 6 March (8 AM Sunday) with a moist front producing a band of organized precipitation extending from southwest to nor...

Don't be fooled by our current stretch of splendid spring weather.  Periods of snow are coming back to the mountains starting late Friday and continuing through the weekend, although it's a bit of a crap shoot how much the resorts will get. Basically, we will see a series of three troughs moving across the region.  The GFS forecast below shows the first trough over southern Utah and northern Arizona at 0000 UTC 5 March (5 PM MST Friday), with some scraps of snow showers extending northward through northern Utah and a trailing trough over northern California.  That trailing trough similarly tracks to our south and at 0000 UTC 6 March (6 PM MST Saturday) it also has some snow showers extending northward through northern Utah.   As that trough exits, a third trough drops across Utah from the north-northwest, bringing additional snow showers.   As things stand now, there's no clear consensus amongst the various models concerning the timing and intensity of...