US: Adverse winter weather forecast across northwestern regions through at least early Nov. 6

Adverse winter weather is forecast across parts of the northwestern US through at least early Nov. 6. A low-pressure system moving into the region from the Pacific Ocean is forecast to bring heavy mountain snow and strong winds over the coming days. Snowfall accumulations of over 20 cm (8 inches) are expected across elevated parts of the region. Hazardous travel conditions are likely due to reduced visibility caused by blowing snow.

As of early Nov. 4, the National Weather Service (NWS) has issued blizzard warnings for parts of northwestern Montana and winter storm warnings across parts of northern Washington, northern Idaho and central and northwestern Montana. A winter storm watch is in place for parts of north-central Montana and winter weather advisories are in place across parts of central and northeastern Washington, far northern Idaho, and central and southeastern Montana. High wind warnings and wind advisories are also in place across parts of the affected area. 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 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.