April showers, high temps lead to rapid snowmelt
As recently as February, hydrologists were celebrating a stroke of good fortune in the form of a mid-season snowstorm. Snowpack was at about 88% of normal by Feb. 25.
But a lot can change in mere weeks, and now it's changed for the worse.
The Hood, Sandy, Lower Deschutes basin is currently at about 32% of normal snowpack.
According to Julie Koeberle, hydrologist with the Oregon Snow Survey, an early season deficit of snowpack in December and January, compounded by the recent spike in temperatures in the region, have concocted the perfect storm for a not-so-good water year.
April rain and 80-degree days in early May appear to have been the catalyst for the sudden change in outlook.
"We got over twice the normal snowmelt rate in April," Koeberle noted.
Last year around this time, the snowpack sat at about 63% of normal.
"Some of these lower elevations still had snow at this time last May," she said. "Whereas the rest of the state this year is actually a lot better than it was last year."
Koeberle noted that the overall snowpack situation is easily assessed by looking at levels at various SNOTEL recording sites around Oregon.
"There are eight different sites," she said. "At this time of year, four of them usually have snow — this year it's only two."
In other parts of the region, especially the Umatilla-Walla Walla-Willow basin, snowpack levels are well above normal, ranging from 109% to 169% of normal.
"2017 was the last time the whole state was at normal or above-normal levels of snopack at the same time," Koeberle noted.
She is hopeful, however, that the cool wave that brought temperatures down into the 50s and 60s last week "won't stop the melt, but possibly slow the rate."
While ski and snowboard resorts on Mount Hood are wrapping up strong seasons going into Memorial Day, positive powder can be misleading and doesn't always translate into positive snowpack.
It's hard to tell this early if the region's lack of May snowpack will contribute to a drought-filled summer, Koeberle also noted.
Mount Hood appears under current conditions as "abnormally dry," but of course the situation could change.
"I don't think drought is out of the question," Koeberle admitted. "Though none of the regions are in a drought category."