Dry Post April Fools

April got off to a good start with the April Fool's storm, but since then, it's been dry.  That dry streak looks to continue through the work week with all members of the Utah Snow Ensemble flatlined for Alta-Collins until 1200 UTC 12 April (6 AM MDT Saturday).  

A few members are excited about snow on Saturday night and Sunday, but most are producing snowfall amounts in the low single digits.  The reason for this is a compact upper-level trough expected to move across the northern Rockies over the weekend.  At 1800 UTC 13 April (Noon MDT Sunday), it's centered over Montana in the latest GFS forecast. 

The trough is fairly dry on its south side, so most of the model runs are giving us a good hard freeze but not a lot of snow.  Basically a good recipe for bone-rattling coral reef conditions, perhaps with a skiff of snow on top on Sunday.  Sounds bad.

If the trough can dig more than currently advertised by most of the members, perhaps we can do better.  About 10% of the ensemble members produce 10" or more by 6 PM Sunday.  Those odds are long, so yardwork is looking like a good option unless things change.

It's Better to be Lucky than Good

Yesterday was one of those days when if you were skiing at Alta in the afternoon, consider yourself blessed or, alternatively, it's better to be lucky than good. 

From 1100 to 1600 MDT, Alta-Collins picked up 9" of fresh, including 3" in an hour from 1200 to 1300 and then again from 1400 to 1500.  Water equivalent was .46", so this was 5% water content.  Winds on Mt. Baldy during that period never guested over 10 mph.  

I took a look at forecasts from the 12Z models on the prior day (2 April) and the GFS was going for nothing.  The HRRR .15" water and 2.7" of low-density snow.  Even yesterday morning, expectations were low.  The Utah Avalanche Center Forecast that morning called for 0.5 to 1" of snow.

This isn't to throw them under the bus as they do a great job, but just to illustrate that yesterday's snowfall was pretty unexpected.  It wasn't handled well by the models or the forecasters.  So what happened?

Well, morning broke with not much happening other than a few scattered snow showers.  At 1459 UTC (0859 MDT), there were some light returns on radar, but nothing to get excited about.  

However, the flow was light and the airmass unstable, and with a little surface heating, convection began to get going.  By 1857 UTC (1257 MDT), during an hour in which Alta picked up 3" of snow, localized convective snow showers had developed over portions of the central Wasatch, especially around Little Cottonwood, and the high terrain down to Mt. Timpanogos.  

Even then, the radar wasn't all that impressive, but the relationship between radar reflectivity and snowfall rate is not a good one.  Low-density snow of the type that fell yesterday often doesn't light up radar screens.  This is why it's so valuable to have weather cams and automated snow depth sensors to monitor actual conditions at the ground.  

The development of the first snow showers over high terrain was probably favored by the light flow and unstable conditions, with daytime heating yielding upslope flow and convergence over the mountains.  

The convection became more widespread with continued surface heating as evident in the 2033 UTC (1433 MDT) radar image from another period when Alta got 3" in an hour.  Nevertheless, snow showers persisted over upper Little Cottonwood.  

It's very difficult to reliably predict the location and intensity of these snow showers.  We can anticipate their development, but questions of where, when, and how intense are hard to answer reliably.  Neither our current models nor human cognition are very good at distinguishing a situation like the one yesterday from one where the snow showers are less productive and maybe provide light accumulations. The processes are simply too small in scale and too sensitive to small changes in the atmospheric stability and moisture content.  Basically, yesterday really was a tough forecast, at least with lead times of more than a couple of hours. 

I suspect if you were skiing yesterday afternoon, you probably didn't care.

About That New Ski Resort in the Oquirhhs...

Hopefully most of you have figured out that the previous post, New Ski Resort to Open in the Oquirrhs, was April 1st foolery.  

A good April fools joke needs to be somewhat believable, so let's break down that post a bit more.

First, the idea of development and possibly a ski resort in the Oquirrhs is quite believable.  Surely as the Wasatch Front metro area expands and the Salt Lake, Tooelle, and Utah Valleys are paved over, there must be developers with an eye on the undeveloped island that is the Oquirrhs.  In fact, Kennecott Land once spoke quite seriously about building a ski resort on their property in the Oquirrhs.  If a ski resort can be built in the snow desert and scrub oak of the Mayflower area, eventually one will probably come to the Oquirrhs.  

Is snow as plentiful in the Oquirrhs as the Little Cottonwood?  No.  The Rocky Basin Settlement Snotel in the southern Oquirrhs at 8700 feet has a median peak SWE of 24 inches compared to 43 inches at 9100 feet at Snowbird.  The Rocky Basin Settlement number though is pretty close to the 25 inches at Thaynes Canyon (9250 ft) in the upper reaches of Park City Mountain Resort.  However, the Oquirrhs also get about as much lake-effect as the Cottonwoods.  Below is the water equivalent snowfall (left panel) produced in lake-effect storms showing that the SNOTELs in the Oquirrhs are on par with Mill D North and Snowbird.  

Is there a powder Shangri-La as I suggest in the post?  Probably not.  I haven't been touring in the Oquirrhs this winter as suggested by the post, but I have in the past.  My guess is that there is no magic microclimate like Little Cottonwood in the Oquirrhs, although there are more mountain lions and fewer people.

Is snow farming from season to season a real thing?  Yes it is.  That article from Levi was real.  They are piling up snow, preserving it beneath geotextile blankets, and using it to open the following season.  Could such a thing happen in Utah?  I don't know, but there is the expertise at the U to figure it out and it strikes me as potentially being worth looking into as it preserves water, energy, and money.  Perhaps it would be most feasible at a place like Alta which typically closes when the snowpack close to its deepest so there's no impact on their skiing business to pile up the snow at the time of peak snowpack.  Maybe they could preserve enough to have cover for Mambo->Corkscrew come the next November.  Or Main Street where there's no snowmaking but maybe they could preserve snow near the base of Mt. Baldy which has less total incoming solar due to topographic shading.  

And finally, we have the extension of the red-line Trax into the Oquirrhs.  That was pure fiction designed to give away the April 1st foolery.  There are no such plans.  We can't even get rail to our current ski areas.  

New Ski Resort to Open in Oquirrhs

Over the past several months I have been working with a group of investors developing a new ski resort for the Oquirrh Mountains west of Salt Lake City.  My non-disclosure agreement expired today, so I thought I would take the opportunity to talk about their plans.  

The Oquirrh Mountains have extensive amounts of private land, mainly owned by Rio Tinto/Kennecott.  This investment group, however, owns approximately 8000 acres of land near the ghost-town of Ophir at elevations between 7000 and 10000 feet elevation.  You haven't seen me much in the Wasatch this winter because I've been doing a lot of ski touring on the property, avoiding crowds and getting to know the dry powder of the Oquirrhs on an intimate basis.  

I thought snowfall wouldn't be as plentiful as in Little Cottonwood, but after skiing a season there, I'm pretty certain the resort gets more.  It's simply an incredible microclimate, fueled by lake effect funneled into a terrain concavity.  If you think Alta gets a lot of snow in northwest flow, wait until you see this place in northerly flow.  I've toured in five storms with snowfall rates of more than 4" an hour.  There's little doubt that this is the future of lift-served skiing in northern Utah.  

In addition, to provide insurance against climate change, the investors have secured substantial water rights for snowmaking and are planning on developing Utah's first extensive use of snow farming in order to recycle snow from season to season.  They have hired an expert from Levi, Finland, where this is now being done to preserve snow from one season to the next.  

In fact, they are planning a trial run as they build out the resort over the next 18 months.  Next season, while they will still be under development, they will start making snow on what will be their signature run, Showcase. Comparable in length and pitch to famed upper, mid- and lower warm springs run at Sun Valley, the plan is to blow snow into deep piles next winter and then preserve those piles through the summer by covering them with white, geotexttile blankets to reflect sunlight and insulate the snow piles, allowing as much as 70% of the snow to survive through the warm season.  

They then plan to open the 2026/27 season in mid September with 3000 vertical feet of skiing on Showcase.  They expect to do this each season moving forward, pipping Snowbird for Utah's longest season.  

The main challenge at this stage is figuring out how to get people to the base of the resort.  The investors are currently working with UTA on plans for an extension of the Trax Red Line through an old mining tunnel in the eastern Oquirrhs.  Incredibly, this tunnel is built at grade, allowing light rail to deposit skiers at the base of the resort without having to use an expensive cog-railway design.  

I anticipate that this development will completely transform skiing in northern Utah.  Once skiers get an appetite for the dry powder of the Oquirrhs, Little Cottonwood will be an afterthought and the red snake will be dead.