US: Adverse winter weather forecast across western regions through at least early April 8

Adverse winter weather is forecast across parts of the western US through at least early April 8. A very strong low-pressure system has brought heavy snow to the Sierra Nevada and will spread rain and snow into the interior West over the coming days. Heavy snow over the Sierra Nevada will weaken late April 4 as the snow, rain, and winds shift eastward. 15-30 cm (6-12 inches) of snow is forecast to accumulate over northern Nevada as well as Sierra Nevada, ranges of northeastern California, Sawtooth, and Blue Mountains. High winds of 56-72 kph (35-45 mph) are likely, especially over parts of the Great Basin and Intermountain West. Snow of 10-20 cm (4-8 inches) is forecast to spread into the Northern and Central Rockies late April 5-6. Hazardous travel conditions are likely due to reduced visibility caused by blowing snow.

As of late April 4, the National Weather Service (NWS) has issued winter storm warnings across southwestern and northeastern California, northwestern Nevada, far northeastern Oregon, and far southeastern Washington. Winter weather advisories are in place across parts of northern, central, and southern California, northern Nevada, far northeastern Oregon, western Idaho, and northwestern Montana. High wind warnings, watches, and advisories have been issued across parts of the Great Basin and Intermountain West. Officials could update and extend the coverage of the weather alerts over the coming days.

Snow accumulations are likely across the affected region, especially at higher elevations. Lesser accumulations are possible where sleet and freezing rain mix with the snow, and precipitation is less intense. In addition to the heavy snow, strong wind gusts will likely lead to periods of blowing and drifting snow in some areas. Sporadic power outages could occur throughout the affected region.

The winter weather will likely cause further ground and air transport disruptions over the coming days. Traffic and commercial trucking delays are probable along regional highways. Dangerous and challenging driving conditions are likely on secondary and rural roads in the affected states as maintenance crews prioritize clearing major routes. Authorities will probably close stretches of highways if driving conditions become too hazardous. Flight delays and cancellations are likely due to ground stops and deicing operations at regional airports.