A powerful Pacific storm system is moving into Utah from the west today after dumping heavy amounts of snow in the California’s Sierra Nevada Range (measured in feet) over the past couple of days. The image below shows this morning’s water vapor satellite imagery, which clearly shows the deep moisture streaming into Utah from the southwest (image source: NOAA).
Along with the deep moisture, warmer air from the southwest has also advanced into Utah ahead of this system. As a result, we will see mostly rain falling in Salt Lake City and the I-15 corridor throughout the day Thursday with temperatures in the 40s. Snow levels could rise to 6,000′ or higher this afternoon.
Above the rain/snow line, heavy snow will fall in the Wasatch today and tonight, much to the delight of skiers who will enjoy some deep powder conditions on Friday. For the Park City area, temperatures may be warm enough this afternoon to prevent significant road impacts, though slushy accumulations are certainly possible. The below image shows HRRR-model projected temperatures this afternoon across Utah (image source: weathermodels.com).
The biggest travel impacts with this storm will occur tonight through Friday morning as a cold front arrives. Road conditions will quickly deteriorate across the Park City area as well as Big and Little Cottonwood Canyons as heavy snow continues to fall as colder air filters into the region.
The heaviest precipitation will occur through roughly midnight tonight, but additional moisture will linger into Friday as well. Late tonight, we should see a transition from rain to snow across the Salt Lake City area and the I-5 corridor, with snow expected to impact the Friday morning commute.
Temperatures are projected to be close to freezing Friday morning in downtown Salt Lake City, and the higher snowfall amounts along with more significant pavement impacts will occur across the higher elevation benches across the metro area.
For snowfall amounts, projections are generally in the 1-3″ range for central Salt Lake City along the I-15 corridor, with higher amounts across the higher elevation benches. For the Wasatch, the town of Park City could see 7-14″, while the higher elevations of the Wasatch ski areas will likely be in the 1-2 foot range with isolated higher amounts possible. The next image shows the HRRR model’s projected snowfall amounts across the area over the next 24-hours (image source: weathermodels.com).