La Sal Summary - Snow, Weather and Avalanches

The La Sal Avalanche Center based out of Moab, Utah has been operating since 1988 providing avalanche and mountain weather bulletins for SE Utah.  The LSAC forecasts for the La Sal Mountains SE of Moab and also the Abajo (also known as the Blue) Mountains about an hour south of Moab near the town of Monticello. The La Sal Mountains are the second highest mountain range in the state of Utah with more than 10 named peaks exceeding 12,000 feet. Both the Abajo and La Sal Mountains rise several thousand feet above the Colorado Plateau forming "Island Ranges" that are exposed severe storms and winds from all directions of the compass.

Temperatures are cold during SE Utah winters with alpine desert conditions and low relative humidity. For these reasons the La Sal and Abajo Mountains are classic continental peaks. Strong temperature gradients, typically lead to the development of a weak "Colorado Snowpack".  Large climax avalanches are the norm for at least one cycle each winter.  The 2010-2011 winter was no exception.

Recreation in the La Sals is divided between mechanized and non-mechanized users with the latter group probably reaching larger numbers. In the Abajos, mechanized users are a large majority and backcountry ski traffic is limited to a handful of skiers every season. There has been no formal data collection to try and determine actual use in either range, but use appears to be steadily on the rise. The inclusion of Mt. Tukunikuvatz (La Sals) in the book "50 Classic Ski Descents of North America" will likely enhance this trend. With this trend - it should be recognized - that there have been very few  skier, snowboarder or mechanized recreationist involvements with snow avalanches in SE Utah. No skier or rider has been buried or injured in SE Utah since the accident in 1992 that took 4 lives. Since then, the Mountains of SE Utah, especially the La Sals have earned a reputation as an unforgiving range with an unstable snowpack and unfriendly slope profiles. This may be true, and it seems that backcountry users of all types in SE Utah refrain from making hasty decisions when traveling in backcountry terrain.

November - December

The avalanche center officially opened it's doors on Dec 6th but Dave and Max snuck a few unofficial ski tours in before the gates opened. November had been a generous month. When the center opened we had already 30 inches on the ground at the Gold Basin Study Plot at 10,000 feet and the month of November had recently ended with 83 inches of new snow for a finish of 152% of normal water. Things were looking good for stability and overall ski conditions. La Nina, it seems had other plansfor SE Utah. High pressure took over for the bulk of the month and by mid-month snowfall totals had dropped to 100% of normal in the La Sals and a paltry 37% of normal in the Abajos with only 9" of snow at the Camp Jackson Study Plot. The classic rot had begun and development of faceted crystals in the shallow SE Utah snowpack continued on its typical yearly course.

The snowpack was setting up for a dramatic event and mother nature delivered with a major storm that started on December 17th. While not as dramatic as the snowfall totals were in other parts of the southwest, by the 24th, over 4 inches of water had fallen in the La Sal mountains and over 7 inches of water equivalent had fallen in the Abajo Mountains. Avalanche warnings for both the La Sal and Abajo Mountains were issued.  High density snow totals reached  22 inches in the La Sals and 25 inches in the Abajos (with rain). The balance was tipped and the snowpack produced some dramatic avalanches. Another 17" storm just before New Year's capped off a snowy month.  We finished the month at 130% of normal snow water equivalent in the La Sals with 35 inches of snow at the La Sal Snotel site at 9800 feet and 61 inches at the Gold Basin Study plot.

Crown of this Avalanche on Mt. Peale was estimated at over 3000 feet wide. (photo taken 12/24/2010 - Brian Murray)

 January

The Christmas and New Year's storms produced dramatic slides and great ski conditions. Avalanche activity following the new year's storm took out most of the major paths that hadn't run the week earlier but quickly quieted down and remained quiet for the remainder of the month. Then something proceeded to happen in SE Utah that is quite rare. The wind didn't blow. In an amazing period lasting for the first 3 weeks of January, calm winds ruled, skies were mostly clear and ski conditions were exquisite. Small non-violent storms freshened things up every now and then. A rare mid-winter treat for SE Utah. Skiers and Riders were thrilled and on the heels of a major avalanche cycle some big lines were skied using avalanches as safe approach lines.

The only drawback to the glorious weather was the cold clear nights. Very cold in fact. Temperatures as low as -18 degrees F were measured at 10,000 feet There were many nights where cold temperatures reached subzero temperatures during the second week of Jan. Our snowpack started to deteriorate and develop severe faceting over this period. All in all, low snow totals for the month, cold temperatures and light winds contributed to make the month of January most memorable for good conditions. We measured 56" of new snow at the La Sal Snotel in January. The month ended with 34 inches of snow at the La Sal Snotel and 55 inches at the Gold Basin Study plot. Our percentage of normal water equivalent dropped from 159% to 104%.

Large Climax Avalanche in Red Snow Cirque,Gold Basin, La Sals after New Years' Storm (Ryan Schatzenbach photo)

February

In stark opposition to the month of January, the winds of February were the highlight of the month and skiing and riding conditions suffered as a result. The snowpack rotted as temperature gradients continued thei                                                                    r work on the snow that had been laying around for a month or more and the winds alternately stripped or loaded slopes with what snow they could move. Over Feb 3-4 there were 15 hours with gusts over 60 MPH and 2 hours with gusts over 70 MPH measured at Pre-Laurel Peak (11,700') in the Middle Group of the La Sals. There were 17 hours with average wind speeds over 40 MPH over the period as well. Ski conditions did not fare well. This trend continued through the month.

On the 20th of February, there was a strong storm that affected the Abajo Mountains much more strongly than the La Sals and an Avalanche Warning was issued for the Abajos mountains. The Abajos (also known as the Blue Mountains) received 12" of snow and 1.8" of water with high winds falling onto a highly layered and weak snowpack. Winds again returned after this storm and the good conditions of January were but a memory. Small storms combined with the high winds were just numerous to keep spring corn conditions out of reach. We finished the month measuring only 37" of new snow at the La Sal Snotel.  With a final snow total of 33 inches, the La Sal Snotel site actually lost an inch on the total stake. The Gold Basin Study plot added 5 inches to finish at 60"

Dirt in the snowpack from late February winds. (photo Karl Kelly)

March- April

The month arrived with the snowpack in a poor state: A wind tortured, layered mess of facets, sun crusts, wind crusts and surface hoar as a result of nearly two months of dominant La Nina high pressure. Small storms kept spring conditions from arriving and good powder skiing was on tap for most of the month with spring conditions being limited to valley elevations. Accumulations were mostly light, although 16" of new snow was measured on the 8th of March ushering in a late season period of HIGH avalanche danger for a few days. At least one old snow avalanche was noted during the ensuing avalanche cycle, highlighting the lasting deep instabilities the SE Utah snowpack was still capable of producing. HIGH  avalanche danger would again be reached  for the 3/26 forecast with up to 10" of new snow and "belligerent" winds from the south. March this year brought weather we typically experience in January and only the very rare day of corn skiing was experienced before the LSAC closed for operations on April 2nd. For the month of March, snow Totals were 73" new snow, 35 inches on the Total stake at the SNOTEL site, and 76 inches on the total stake at the Gold Basin Study Plot. Just before the close of the season, on 3/29, the La Sal Snotel was reading exactly 100% of normal snow water equivalent. An excellent measurement for the 2010 - 2011 season.

 "Moab Lanes" on the NE face of Mt. Tukno with a small but deep mid level chunk of snow missing that released in the 3/8/2011 storm. Matt Van Scoyoc Photo.