SNOQUALMIE PASS, Wash. – Travel could be challenging this weekend, especially over Stevens and Snoqualmie passes, as snow continues to fall over the Cascade Mountains through the weekend.

The National Weather Service (NWS) has issued a winter weather advisory that will remain in effect until 4 p.m. Saturday.

15 to 20 inches of snow accumulation is expected at Stevens Pass (US 2) between Friday and Saturday evening, creating “wintry driving conditions.” Between 4 and 6 inches of new snow could be seen at Snoqualmie Pass before the snow turned to rain Saturday morning.

The NWS said travel could be “very difficult to impossible” due to active weather over the mountains.

This follows a difficult few days of travel in the passes with intermittent closures on eastbound Interstate 90, primarily due to outages and collisions. Conditions were also difficult on US 2, particularly for eastbound travelers.

Motorists should keep a close eye on pass conditions before setting off and ensure they carry chains and emergency supplies in their vehicles. You should also take more time on the roads and plan for delays.

Here’s what WSDOT recommends drivers pack emergency gear when driving in hazardous weather:

• flashlight
• Batteries
• Ceiling
• Snacks
• Water
• Gloves
• Boots
• First aid kit
• Tire chains
• Ice scraper/whisk
• Jumper cables
• Street flares