Weathercatch: Summerlike heat caused quick snowmelt and rising rivers

An abrupt snow melt in the mountains brought on by the recent temperature warmup has sent fast-moving and very cold waters cascading into a number of rivers and streams in the Inland Northwest.

Those of you being lured to bodies of water to fish or go boating or paddling are urged to be especially cautious, which includes wearing a life vest. You may encounter swift currents and shockingly cold temperatures. Even the pet dog could be at risk.

“Cold water temperatures and strong currents will pose a significant risk of cold water shock, hypothermia, and drowning,” the National Weather Service Spokane wrote in a special weather statement.

The first part of April was cold and snowy, which kept melting snowpack to a minimum until recently. On April 24, the high temperature in the Spokane area was only in the mid 50s. Four days later, it climbed to 77 degrees. The next day, Saturday, hit 84 degrees and Sunday tied a record high at 82. Following a brief temperature dip on Monday of this week, the mercury topped out at a record-breaking 85 degrees on Tuesday and continued to hover 10-20 degrees above normal through today at high and low elevations.

Meanwhile, water temperatures are running mostly in the frigid 40s. Temperatures below 60 degrees are considered “very dangerous,” according to the National Center for Cold Water Safety.

Melting snow in the mountains of Eastern Washington and North Idaho is a normal part of nature’s water cycle and ideally, the process is gradual. But this year, a sudden and steep spike in air temperatures kick-started a faster melt. The snow depth on Quartz Peak in Spokane County (elevation 4700 feet) dropped from 50 inches on April 24 to 35 inches in 5 days and continues to rapidly drop today.

The possibility of rain tonight and Friday may “bring more rises to creeks and rivers,” according to the weather service. Those waterways include the Spokane, St. Joe, Coeur d’ Alene and Stehekin rivers.

A significant weather cool-down is expected to move in Friday and extend into next week. Although cooler air temperatures will slow down the volume of snowmelt coursing into our waterways, the water temperatures will remain very cold.

Nic Loyd is a meteorologist in Washington state. Linda Weiford is a writer in Moscow, Idaho, who’s also a weather geek.