Snow is building on high elevation roads that have not yet closed for the season, and forecasters expect it to keep falling into Wednesday morning. The National Weather Service has winter weather advisories in effect across four mountain zones, with up to 14 inches of snow forecast at the highest elevations and anything from a coating to a few inches on the roads below.
Several seasonal routes inside those zones have not closed for the winter yet, and two of the advisories single out drivers who are not prepared for winter conditions.
The Advisories
The largest totals are forecast for Utah’s Western Uinta Mountains, where NWS Salt Lake City continued its winter weather advisory at 11:59 p.m. ET Monday and now expects an additional 8 to 14 inches, mostly above 9,000 feet. The zone takes in Moon Lake and the Mirror Lake Highway. The same office extended a second advisory for the Wasatch Mountains south of I-80 at the same time, calling for 3 to 6 inches in upper Little and Big Cottonwood, with snow concentrated above 8,500 feet and heavier amounts above 9,000. Both run until 8 a.m. ET Wednesday.
The NWS Riverton advisory for the Wind River Mountains splits the forecast sharply by elevation, with a coating to 3 inches up to 9,000 feet and 3 to 12 inches above that line, and warns that travel could be difficult, especially across the backcountry. It also expires at 8 a.m. ET Wednesday. In Nevada, NWS Elko continued its winter weather advisory for the Ruby Mountains and East Humboldt Range at 2:18 a.m. ET Tuesday, with an additional 5 to 10 inches expected before it expires at 8 p.m. ET Tuesday and no breakdown by elevation.
The Seasonal Passes
NWS Salt Lake City names Bald Mountain Pass on the Mirror Lake Highway directly, noting that seasonal roads like it remain open and “may pose a significant risk to under-prepared travelers.” The advisory asks anyone on high elevation routes to be ready for periods of accumulating road snow, and it does not say whether the pass will close while the event is under way.
Guardsman Pass gets similar treatment in the Wasatch advisory. Forecasters expect only minor accumulations in the upper Cottonwood canyons, but they single out Guardsman as the route likely to see higher snowfall. South Pass in Wyoming is forecast to see far less, with a coating to an inch forecast mainly on grassy surfaces, although NWS Riverton still lists the commute across it among the expected impacts.
Timing
The Nevada advisory ends first, at 8 p.m. ET Tuesday. Everything else runs through Tuesday night and expires at 8 a.m. ET Wednesday, which places the overnight hours inside the advisory window. None of the four advisories says when road surfaces are expected to recover once the snow ends.
What Early Season Snow Means For Your Car
A car that has spent the summer on dry pavement often goes into its first snow without any changes. Summer washer fluid can freeze on a cold windshield and smear the glass when visibility is already poor, and wiper blades that have sat in the sun since spring tend to streak on wet snow.
Many performance cars and some trims of everyday sedans and crossovers leave the factory on summer tires, whose compound loses grip as temperatures approach freezing. On a snow-covered pass, traction and stability control can only work with whatever grip those tires still provide.
On the descent, a lower gear holds speed without constant braking. Antilock brakes let a driver keep steering under hard braking on snow, although they do not shorten the stopping distance.
Road Conditions
The Utah Department of Transportation posts current winter road conditions for the Uinta and Wasatch routes, and NWS Salt Lake City publishes snowfall forecast graphics with official, high end and low end amounts. Drivers in Wyoming and Nevada can call 511 for the latest road reports, as both NWS Riverton and NWS Elko advise.
