Those traveling through Washington’s mountain passes this weekend will see light precipitation, including snow, according to the National Weather Service.
One to 3 inches of new snow accumulation is expected on Snoqualmie and Stevens passes Friday night, said meteorologist Jacob DeFlitch. While there may be a period of increased intensity Saturday night, accumulation is still expected to stay between 1 and 2 inches.
White Pass will see a similar pattern, DeFlitch said, with possibly an additional inch of snow Saturday night.
Highs in the mountain passes will be between the upper 30s and low 40s, and the lows at night will fall to the mid-20s, he said. The snow level is expected to be around 1,000 feet Saturday morning and then 2,500 feet during the day, according to the weather service.
Washington State Department of Transportation spokesperson Summer Derrey said the agency is not anticipating any especially adverse conditions in the passes this weekend. Clearing the passes can become difficult to manage when the rate exceeds an inch per hour, she said.
The weekend’s expected light precipitation is due to a low-pressure trough over the Pacific Northwest, resulting in scattered showers rather than the steadier rain during an atmospheric river from the ocean, DeFlitch said.
“Especially during the heating of the day, clouds develop and some of these clouds can produce showers,” he said.
While snow in the lowlands like Seattle may be rare for April, DeFlitch said snow in the mountains in April is not unusual when there is a cool mass of air over the region.
The passes will dry out Sunday with some sun poking through partially cloudy skies, he said. However the region will be back to its usual light precipitation by the evening.
Temperatures will continue to be chilly in the Seattle area, where the average temperature the past week was about 41.5 degrees, according to the weather service.
But once the low pressure moves eastward by Sunday, it will open up the possibility for a sunny day with a high near 55. However, a new frontal system by Sunday evening will bring more rain through at least the first half of next week.
The Seattle Times is tracking this season’s snowpack through maps and charts. For more information, visit st.news/2022-snowpack-tracker. For tips on driving on passes during winterlike conditions, visit st.news/tirechains.