Wasatch Weather Weenies

It's a great pattern for late March with snowfall continuing today.  Overnight, Alta-Collins picked up 6 inches (as of 7 am) and the radar looks pretty filled in as I write this at 7:20 AM. Snow today from 7 AM to 5 PM should add another 3-6" to the stake.  The HRRR says morning will be more active than afternoon, whereas the GFS keeps it going for most of the day.  Let's hope the latter verifies as that might push us above my forecast range.   Periods of snow will continue through Sunday night, with perhaps some snow showers on Monday.  I'm not sure if it will stay cloudy and snowy enough on Monday to help preserve the snow, or if we will start to see the caustic effects of the sun.  After Monday though, warmth and sun return this great powder run will come to an end.

Ski conditions in the Wasatch backcountry continue to be excellent with cold weather and cloudy skies enabling pretty good snow preservation despite it being late March. Over the past couple of days, a lot of the snow that has fallen has been in the form of graupel, which is an opaque, white snow pellet that sometimes takes a lump, hexagonal, or conical form. Graupel often causes the snow surface to have a dippin' dots appearance.   Catch some on your sleeve and take a close look you'll find that graupel particles are aggregates of a bazillion tiny frozen cloud droplets.   Graupel forms in strong updrafts when supercooled cloud droplets freeze on falling snowflakes.  Supercooled means that the cloud droplets are unfrozen, despite being colder than 0˚C.  These droplets freeze on contact.  This process is sometimes called riming or accretion .  If the riming is light, you can still distinguish the original snowflake.  However, at the extreme, ...

The Saturday night frontal passage seemed to provide just what the doctor ordered for transitioning from spring skiing back to proper powder skiing.  I found good skiing yesterday with just a hint of bottom feeding at mid elevations if you kept the slope angles reasonable.   Storm totals per the Alta-Collins site are now over two feet.  Elsewhere, a healthy lake band developed overnight, but raged over the western Salt Lake and Utah Valleys.   It has since broken up some but scattered lake-effect snowshowers continue this morning, albeit a bit farther west than central Wasatch skiers would like.  The unsettled post-frontal weather will continue through Tuesday evening.  Although not in the lake-effect now, expect periods of snow showers throughout this period in the Cottonwoods and perhaps even a thunderstorm or two in the afternoons.  For the period from 6 AM MDT this morning through 6 PM 12 AM MDT Wednesday March 27, the GFS produces .79" o...

Pretty good delivery of the white in the upper Cottonwoods yesterday afternoon and last night. As of 6 AM, Alta-Collins is already at 13 inches with 1.32" of water.  That's a mean water content of 10%, although I suspect it's right side up.  We need some high density snow to bury the coral reef anyway.  All in all this is good news.   Radar early this morning showed a fairly active northwesterly flow pattern.     Expect periods of snow in the northwesterly flow to continue today.  The HRRR really lights it up with .66" of water and 11.1" of snow at Alta from 7 AM to 5 PM MDT today.  The GFS is not as excited puts out .19" of water and 3.6" of snow.  A big reason for this discrepancy is the HRRR really gets things going in the northwesterly flow, including some lake effect, as illustrated by the forecast radar image for 2000 UTC (2 PM) this afternoon.   And for the 6-h period ending at 0000 UTC (6 PM MDT) the HRRR is genera...

After about a week of splendid spring weather, winter will be returning to the Wasatch Range today with the arrival of a cold front this evening.   Although there will be some periods of high-elevation snow and low elevation rain ahead of the front, the main action will be associated with the frontal passage which will bring a few hours of steady snowfall overnight.   The cold-front is very apparent in the latest HRRR run with an abrupt drop in the wet-bulb zero height at between 7 and 8 PM.   We base the wet-bulb zero level estimate on the model forecast from the airport (if we used data from Alta we would not be able to estimate snow level most of the winter since there's no data below ground), so expect that drop to be more like from 8-9 PM in Little Cottonwood.  Snow levels are usually a bit below the wet-bulb zero, so expect them to be in the area of 7000-7500 feet today, possibly higher in the afternoon with heating, and then drop to near bench l...

If you look carefully, you can see a couple of clouds in the Mt. Baldy web cam from Alta Ski Area this morning. Source: Alta Ski Area Those are not enough, however, to mar the incredible run of beautiful weather we have had since the demise of the easterlies on Saturday.   Indeed, that run will continue today with clear skies and temperatures into the upper 60s in the valley.  If we can't have powder, this is a pretty good alternative.   A weak short-wave trough will come through tomorrow and bring in a few more clouds and maybe a spritz of a shower or upper-elevation snow shower for the mountains tomorrow.  Significant weather will hold off until the weekend when a cold front is expected to push across northern Utah on Saturday.  Current forecasts suggest that the front will arrive in the afternoon.  Below is the ECMWF forecast valid 2100 UTC 23 March (3 PM MDT Saturday) with the front approaching Salt Lake City. A real question mark for skiing w...

Along with graupel, sastrugi is one of my favorite weather-related words and I saw plenty of it ski touring yesterday.   Sastrugi is defined by avalanche.org as "heavily wind eroded snow with wavy textures." Sometimes it looks rough or pockety.  In the photo below, it appears there is avalanche debris on this slope, but in reality it is all sastrugi.   In some areas, the sastrugi was dense wind board and generally supportive of a skier.  In others, it was actually somewhat soft and didn't ski to bad on the descent. Each turn was a mystery! Although I like sastrugi as a word, it's not my favorite snow surface to ski.  We can blame the sastrugi in this case on the multiday easterly wind event that has been affecting the Wasatch Range and Front since Thursday.  Observations from Alta's Mt. Baldy show the winds veering (turning clockwise) from southwesterly just prior to 1200 MCT 12 March (Tuesday) to north by 0000 MDT 14 March and then locking in wi...

We will return to regularly scheduled programming soon, but I hope you will entertain one more additional post on our misadventures in Austria. Ischgl After skiing the Arlberg, we decided that we should get up early the next day and ski Ischgl.  We had put off skiing long enough and Erik seemed to be skiing decent on the pistes with his arm in a sling.  It's a bit of a haul to Ischgl on transit, so got up early, caught a 6:41 train to Landeck, and then a bus up the Paznaun valley to Ischgl, arriving at about 8:30 as the valley lifts opened.   Ischgl is located in the next vavlley south from St. Anton, just 12-km away as the crow flies.  It receives a bit less snow since it is deeper in the inner Alps, but has two distinct advantages for skiing.  It has more high elevation terrain and it has predominantly northwest aspects.  Although not as spread out as St. Anton, it is a big resort, with a vertical drop of almost 5000 feet.  It is also known for ...

Previously on Wasatch Weather Weenies, the ski plans of my son and I in Austria were marred by a dislocated shoulder and we began to travel around Tyrol and environs using Innsbruck as a base.     After going to Sölden (see Austrian Misadventures, Part I ) where I was able to do some skiing, the weather deteriorated and we elected to shift back to more traditional sightseeing for a couple of days. Salzburg and Innsbruck My son had never been to Salzburg, so we grabbed an early morning train, consumed pastries on the way, and went for a visit.  On one of the OBB railjet trains, that reach speeds of up to about 145 miles per hour, it's less than a 2 hour trip (one doesn't go that fast the whole way, but it's nice to fly along in sections).  Many people who visit Salzburg do the Sound of Music tour.  I have been to Salzburg several times and am proud to say that I've yet to do it.  Instead, we visited the Hohensalzburg Fortress, a medieval monster that si...

  "Plans are worthless, but planning is everything" - Dwight D. Eisenhower For the past few years, my son and I have been trying to find a time when our schedules align for a father/son trip that my mother suggested we do after my father and his grandfather passed away.  Pandemic, school, work, and life made finding a block of time difficult for many years.   It appeared, however, we could pull something off this winter over my spring break, so in early January we booked a trip to Austria so that I could give him a proper introduction to backcountry and resort skiing in Tyrol and environs.   We spent a lot of time trying to figure out where to stay, where to ski, etc.  Ultimately we settled on staying the entire trip in Innsbruck since it is easy to use transit to travel to any number of resorts or touring areas from Bavaria to the north to South Tyrol to the south and from St. Anton to the west to Kitzbuhel in the east.  In addition, I have a num...