Snowy winter helps PNW, but drought still strong influence in the region
A wet winter helped weaken the multi-year drought gripping Washington, Idaho and Oregon, but the precipitation hasn’t been enough to totally slake the drought, according to federal and regional researchers.
“Drought improvements have been seen over the last several weeks in Washington, leaving only abnormally dry conditions in northern Idaho and northwestern Montana,” University of Montana climatologist Zach Hoylman said in a Monday briefing.
But Hoylman added, “The current drought in the Pacific Northwest is widespread, longstanding, persistent and far from over.”
The last 90 days have been cooler and drier than the region’s thirty-year average. February’s temperatures moderated a bit, but were still cooler than normal, especially in Idaho. Snowpack is looking good so far, but Hoylman cautioned there’s a long way to go until the peak of melting season and its significant influence on river and stream flows.
The findings shared in this week’s drought briefing match weather data reported by the National Weather Service’s Spokane office since late fall. Snowfall in November was 18.5 inches, well above the 30-year average of 6.2 inches. Nearly 17 inches of snow fell in December, three inches more than the average.
That spigot turned off with the new year. January snowfall was about six inches, less than half the 30-year average amount. February’s figure was even more meager: 4.2 inches, against the average of 7.8 inches.
La Nina appears to be winding down, after influencing the Inland Northwest’s weather for the past three winters. While the pool of unusually cool waters off South America’s Pacific coast can produce wet, snowy and cold winters for the Pacific Northwest, this time around La Nina’s biggest storms dumped their water on California and Nevada, said Brent Bower of the National Weather Service’s Seattle office.
The seesaw between cool La Nina and warm El Nino is “basically neutral now,” Bower said. As the year moves into spring and later into summer, Bower said computer modeling favors a shift to El Nino.
Bower also noted current climate outlooks for March indicate the current cooler-than-normal trend is likely to persist. The snowy-wet pattern may wane, and some reduction in drought severity is probable. The current outlooks for wildfire season are neutral.