Accumulating snow expected in Seattle, Everett this weekend

SEATTLE — Confidence is growing about another chance of lowland snowfall this weekend across western Washington, including the lowlands east of Puget Sound.

A cold, arctic air mass has entered the area and will remain in place through the workweek through into the coming weekend. This cold air mass will set the stage for another low-lying snowfall as moisture moves back west of Washington as early as Saturday afternoon and evening as a Pacific frontal system approaches shore. sea.

The first snowfall began over the western half of the Olympic Peninsula on Saturday afternoon for areas inland from coastal waters, spreading inland into the northwest interior and even the Islands. San Juan late Saturday afternoon.

Future radar Saturday afternoon

Future radar early Saturday night

Snow continued to form inland across the entire Puget Sound, including Seattle and Everett, as well as the Kitsap Peninsula and inland southwest Saturday evening and night with snow continuing into early Sunday morning.

Future radar late Saturday night

Future radar on Sunday morning

With the first rain, the temperature will be just cold enough for snow to fall. Temperatures will gradually warm on Sunday, making forecasting for this type of rain difficult throughout the day on Sunday as some snow could turn to a rain/snow mix late Sunday morning and Sunday afternoon with the system set to fall. supplemental daytime heating with any residual moisture. .

Additional humidity moves back into western Washington Sunday evening and night, and it is possible the rain/snow mix will turn back to all-snow Sunday night as temperatures cool down due to loss of daytime heating.

This repeated lowland snow/snow combination or lowland rain/snow mixture is expected to continue into times of the week with night and morning snowfall and afternoon rain. afternoon or rain/snow mixture.

Although it is too early to determine the exact amount of snow accumulation with high confidence, it does appear that mild to moderate lowland snow accumulation is possible with the first snowfall on Saturday night. and early Sunday morning for several lowlands west of Washington, including in Seattle and Everett.

This is where about 1 inch of snow is expected now with up to 2 to 3 inches higher in individual snowfall. Winter weather advisories may be needed for this time frame.

This subsequent system is believed to produce more extensive and more impactful snow accumulation than what the region saw on Wednesday and Thursday.

Modeled snow accumulation forecast

As this snowfall gets closer and a better understanding of temperature profiles and rainfall patterns, KING 5’s First Alert Weather Team will refine the forecast and make more hyper-local snowfall forecasts for the snow event late Saturday and Sunday.

Cascade passes and ski areas could expect 1 foot or more of snow this weekend.