By late Sunday or early Monday, the Okanogan River near Tonasket could crest at 20.63 feet, 1.87 feet shy of the record-holding 1972 flood that wreaked about $20 million of damage across the valley.
The latest measurements Wednesday, May 16, showed the swollen, swirling river at 18.63 feet, and it’s only expected to rise. Hydrographs by the National Weather Service in Spokane show a steady upward trend in the river’s level today to Sunday.
Weather forecasters say the level may then slowly begin falling after midnight Sunday.
The latest north central Washington flood warnings as of Wednesday morning include Okanogan River near Tonasket, Methow River near Pateros, Kettle River near Ferry above Curlew and Similkameen River near Nighthawk.
The Methow River near Pateros measured at 9.82 feet at 5:15 a.m. Wednesday, creeping up on flood stage: 1o feet. It is forecast to rise above flood stage late Friday before midnight and then fall below food stage by Sunday night.
At 10 feet, the Methow River will likely cause minor flooding of adjacent roads and low-lying areas throughout the Methow Valley from Mazama to Pateros. Hitting 12 feet could mean significant flooding in those areas.
The Kettle River near Ferry above Curlew measured at 20.11 feet – 1.61 feet above major flood stage – early Wednesday morning. It is forecast to rise to near 20.6 feet by Wednesday night and the continue to gain to 21.9 feet by Saturday.
The Similkameen River near Nighthawk measured at 14.49 feet – .49 feet above flood stage – early Wednesday. It is expected to rise to near 15.1 feet by Wednesday night and crest at 16.09 feet by late Friday.
Elsewhere, a flood warning for snowmelt in central Stevens and northeastern Ferry counties is also in effect until 5 p.m. Friday, May 18, as increasing temperatures are predicted to exacerbate snowmelt and recharge flooding by the weekend.