An urgent storm alert has been issued in three US states, warning locals to prepare for up to 16 inches of snow starting Thursday.

Heavy snowfall and gusty winds have been forecast in parts of Alaska, Wyoming and Washington.

In Alaska, Thompson Pass is set to receive roughly nine inches of snow through the evening, potentially disrupting both morning and evening commutes, according to the National Weather Service (NWS). 

Strong winds reaching up to 40mph are expected to peak early Thursday afternoon, reducing visibility to around half a mile or less. 

Residents have been warned to be careful when venturing outdoors as icy and slippery surfaces could increase the risk of falls and injuries.

In Wyoming, the Teton and Gros Ventre Mountains are expected to see four to eight inches of snow, with the highest peaks in the Tetons possibly receiving up to a foot by Thursday afternoon. 

Winds could also reach 40mph, creating dangerous travel conditions and reducing visibility, particularly along the Teton and Togwotee passes.

Meanwhile, the Cascades in Washington, including Whatcom and Skagit counties and the Washington Pass, could see up to 16 inches of snow through Friday morning, especially above 4,000 feet. 

Travel along Highway 20, west of the Washington Pass, is expected to be extremely difficult or even impossible, posing significant hazards for commuters. 

Mount Baker may receive as much as 24 inches, while some of the highest areas within these counties could accumulate nearly three feet.

Forecasters expect the heaviest snowfall to occur throughout Thursday, with rates reaching up to an inch per hour in certain locations.  

'If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency,' the NWS stated.

While Thompson Pass is not home to a permanent town, it is a popular route for drivers to access Valdez, where more than 3,000 people live.

Locally, snow is expected today in the region, with visibility dropping to around half a mile or less at times and roughly three inches of accumulation. 

High temperatures will be near 30°F, with northeast winds reaching 30 mph and gusting up to 45mph. 

Tonight, snow is likely to continue with little or no additional accumulation, and temperatures will drop into the mid-20s while winds remain gusty. 

Friday brings a chance of snow, with highs again near 30°F and northeast winds up to 25mph, gusting to 45mph. 

The NWS urges residents and travelers in the affected areas to carry emergency supplies such as flashlights, food, and water, and to monitor local road conditions closely due to the dangerous winter conditions.

The Teton and Gros Ventre Mountains in Wyoming are under the same advisory 1pm MT (3pm ET). 

The population of Teton County, which includes the Teton Mountains, is approximately 23,272 as of 2024. The Gros Ventre Mountains have no permanent residents.

Travelers should exercise caution while crossing Teton and Togwotee Passes, as snow and strong winds may make driving difficult.

The NWS reported that snow showers are expected on Friday, with a slight chance of thunderstorms in the afternoon.

In Washington, mostly rain was forecast in the Whatcom and Skagit counties during the day, switching to a mix with snow in the evening. 

The estimated population of the former is approximately 234,954, while the latter is home to around 132,736 people.

The NWS warned tonight that precipitation may be heavy at times, with rainfall amounts of one to three inches possible. Snow accumulation will reach up to seven inches.

By Friday, the agency warned there could be up to 14 inches of snow in some spots.