By Bill Sheets Herald Writer
Weatherwise, autumn was a Northwest impersonator, sometimes cold, gray and foggy but rarely wet.
The past couple of months, though, the region has shown its true nature — and then some. Not just wet, but sopping wet.
That contrast is reflected in the mountain snowpack. After three months of stunted growth, it’s put on a spurt to reach a more typical height.
“Everything in the Cascades is close to normal,” said Johnny Burg, a meteorologist with the National Weather Service in Seattle.
The Snohomish County Public Utility District provided proof via its annual snowpack measurements last week.
Every March, a couple of PUD staff members take a helicopter into the Cascades to measure snow and water content at three spots in the Sultan River basin. The highest is Stickney Ridge at 3,600 feet; next is Olney Pass at 3,300 feet; and the lowest is Kromona Mine at 2,400 feet.
Last Monday, PUD electrical constructor Mark Shayne and principal engineer Mark Flury found the snowpack at 91 percent of average at the three locations combined, spokesman Neil Neroutsos said. The water content was 75 percent of normal.
“The snowpack was in better condition at the higher elevations,” Neroutsos said.
The snow level at Stickney Ridge was 103.7 inches, about 8½ feet, just above normal. At Olney Ridge, it was 51.2 inches, or 95 percent of normal. At Kromona Mine, it was 42.1, or 76 percent of normal.
“The snow level was kind of popping up and down” the past couple of months, Neroutsos said. “We did get some nice snow in February to make up for the lack of it earlier in the winter, but we had some warmer temperatures in March that caused some of it to come down in rain.”
The utility uses the snowpack information to determine how much water to let through its three dams for hydropower and still have enough for the summer.
The PUD generates about 5 percent of its power by running water from Spada Lake through a pipeline to turbines in a pumphouse four miles downstream on the Sultan River. The PUD also operates small dams at Youngs Creek near Sultan and Woods Creek near Monroe.
The PUD has been taking measurements since 1986. The levels have generally gone in cycles of a few years, with peaks followed by valleys followed by peaks, PUD staffers have said.
That pattern is holding true this year, with the level having dropped from last year’s 159.3 inches at Stickney Ridge, the fourth highest on record. That peak came three years after the recent low, about 60 inches in 2010.
The lowest level at Stickney since the PUD has been taking measurements was 19.5 inches in 2005. The highest was 197.8 inches just three years later, in 2008. Record highs for the other locations are 137 inches at Olney Pass and 125.6 inches at Kromona Mine, also in 2008.
Staff members measure the snow with a long tube marked in inches and feet. The tube is weighed with a hand-held scale to determine the water content. The snow is collected at 10 different spots at each of the three locations and the numbers are added and averaged.
About 80 percent of the drinking water for Snohomish County comes from Spada Lake, via Lake Chaplain, to the city of Everett.
A deep snowpack with lots of water usually means plenty of drinking water for the summer and more hydropower for the county, officials say, though a sunny spring could evaporate some of the snow before it can melt and run down the mountain.
“The Spada Lake Reservoir is looking very good in terms of water levels,” Neroutsos said.
The Climate Prediction Center — the long-range forecasting arm of the National Weather Service — shows higher-than-average temperatures and precipitation for the Pacific Northwest for the next three months.
Bill Sheets: 425-339-3439; firstname.lastname@example.org.