Warm temperatures prompt flood alerts
May 18, 2017
Slightly more than 9.5 feet of snow clung to Ebbetts Pass midnight Wednesday, posing a significant source of spring flooding hanging over Carson Valley.
More than five times the average amount of water was locked up in the snowpack sitting at the top of the East Fork of the Carson River on Thursday with 114 inches, according to snow telemetry maintained by the Nature Resource Conservation Service.
Carson Pass, at the top of the West Fork, reported 86 inches of snow remaining, with 42 inches of water locked up in the snow, or double its average for mid-May.
Sonora Pass had 81 inches of snow as of Wednesday night, or 45.7 inches of snow water equivalent for this time of year.
That snow, coupled with warm temperatures, prompted forecasters to issue a flood warning for the Walker River from Mason down in Lyon County, and a flood watch for the Sierra from Bieber to Bishop starting this weekend. The watch begins 11 a.m. Sunday and will continue through 11 p.m. Tuesday.
Forecasters issued both alerts Thursday afternoon due to the prospect of warm temperatures melting snow in the mountains.
"Rising temperatures this weekend and early next week will produce increased snowmelt in the upper part of the Walker River basin," according to the National Weather Service.
As of 1 p.m. Thursday afternoon, the East Fork was at 5.09 feet at Markleeville or 3 feet below flood stage, according to gauges maintained by the U.S. Geological Survey. A gauge on the East Fork where it enters Carson Valley indicated the river was at 11.24 feet, below the 13.4 foot flood stage.
The river typically crests near midnight, so higher flows are expected tonight. Cool weather earlier this week helped keep snowmelt in check.