A deep, cold, slow-moving weather system was present across the West this weekend. A strong surface low over the western Plains drew low-level moisture northward from the Gulf across the Plains, then westward over the Northern Plains and northern West. The result was a widespread 1 to 2 feet of snowfall across the northern High Plains and the Northern Rockies this weekend. Three to 4 feet of snowfall were reported in isolated areas, mainly in southern Montana and northern Wyoming. Strong winds were also present, due mainly to a strong jet streak which rotated about the midlevel cut-off low over the West, which provided the upper-air dynamics for the weather. Farther east, 1 to 2 inches of rainfall occurred in the Northern Plains, which did cause some minor river flooding on the upper tributaries and mainstem of the Red River of the North.
Where there was a rain/snow mix in the Plains, the snowpacktemperatures were quite warm, and moderate snowmelt occurred and is occurring. Slow snowmelt is also occurring in valleys of the West, where temperatures are slightly above freezing. Across the rest of the snowpack in the West, temperatures are cool.
The system which caused the heavy precipitation across the West and Plains has ejected northeastward into Canada, and little additional snowfall or rainfall is expected today in the northwestern quarter of the coterminous U.S. The southern end of the system's cold front will move slowly across the Southern Plains during the next couple of days, and heavy rainfall is likely there. One to 3 inches is possible in the southern High Plains of eastern New Mexico and northwestern Texas through southern Kansas, and slightly lesser amounts are expected in Texas and Oklahoma tomorrow. Other than those areas, little additional precipitation is expected in the coterminous through Wednesday.
Across the West, air temperatures will moderate to more seasonal values from the cold temperatures this weekend as surface high pressure over the West slowly moderates. Especially at lower elevations where the snowpack is already nearly ripe, moderate snowmelt is possible.
weather.gov
