King County opened its Flood Warning Center this morning to monitor possible minor flooding along the Snoqualmie River.
The Center opened at 11:45 a.m. after the second day of heavy rain across the county. On Nov. 5, the sum of the Snoqualmie River’s three forks was above the threshold to trigger a phase 2 flood alert. These flow levels are expected to only cause minor flooding in low-lying areas along the river.
The center also opened the day before, on Nov. 4, when rainfall brought flows along the river up to a minor flood phase. It was closed later that day.
While the valley hasn’t experienced major flooding yet this year, last winter brought several bouts of flooding, including a severe October flood.
Based on previous reporting, the county is expecting to see similar weather patters to last winter. But it’s difficult to predict flooding. In October 2019, the ground was already heavily saturated by rain, making it easier for the Snoqualmie to flood.
This fall has been drier, meaning rivers have more room to swell.
But looking out through November and December, Puget Sound is expected to experience a La Nina winter, which could indicate a cooler and wetter season.