February 5, 2024
Introduction:
Read more here: https://www.eurekalert.org/news-releases/1033501(Eurekalert) Major snowstorms in Utah’s Wasatch Mountains are both a blessing and a curse. They deliver much-needed moisture that supplies water to the state’s biggest metropolitan area and fluffy light snow to support the world’s finest powder skiing.
But heavy snowfall also wreaks havoc on canyon roads and creates extreme avalanche hazards that can sometimes shut down busy winter recreation sites. Alta at the head of Little Cottonwood Canyon, for instance, can be reached by vehicle only via a winding road that rises 3,000 feet in 8 miles, crossing about 50 avalanche paths.
University of Utah atmospheric scientists have set out to better understand extreme snowfall, defined as events in the top 5% in terms of snow accumulations, by analyzing hundreds of events over a 23-year period at Alta, the famed ski destination in the central Wasatch outside Salt Lake City. The resulting study, published this week in Monthly Weather Review, illustrates the remarkable diversity of storm characteristics producing orographic snowfall extremes in the ranges of the Intermountain West.
The orographic effect occurs when air is forced to flow up and over mountains, which cools the air and condenses its water vapor.
Some of the new findings surprised researchers. For example, they looked for an association between heavy snow and a weather factor called “integrated vapor transport,” or IVT, but found a complicated relationship. (IVT is essentially a measure of the amount of water vapor that is being transported horizontally through the atmosphere).
