Snowfall rewriting records
Snowfall in the Spokane and Coeur d’Alene region since mid-November now equals the legendary winter of 1968-‘69.
As of midday Friday, and with snow still falling, the two seasons were tied for eighth on the record list with 77.5 inches of snow each. Record-keeping for snowfall dates to 1890.
It would only take another 4.3 inches of snow to put 2007-‘08 at fifth on that list.
“Three inches is likely. Four are possible,” said Ron Miller, meteorologist for the National Weather Service in Spokane.
He said the reappearance of La Nina in the tropical Pacific Ocean last fall apparently contributed to the snowy conditions. La Nina has worked its snowy magic other years as well.
Five of the six snowiest winters occurred during La Ninas. A La Nina cools of tropical waters, causing colder storms to be steered into the Pacific Northwest. The storms that repeatedly struck the Inland Northwest had origins over the Gulf of Alaska. The complex storm that paralyzed the region on Jan. 26 and 27 was actually a pair of storms from the Gulf of Alaska and the waters off Oregon and California.
Curiously, the winter of 1968-‘69 came during an El Nino warming of the equatorial Pacific. So did the winter of 1992-‘93, when 87.3 inches of snow was recorded. El Nino is often associated with mild and dry conditions in the Northwest.
Miller said sea surface conditions in the tropics influence the weather, but so do other factors.
“La Nina or El Nino never tells you the complete story,” Miller said. “There’s no hard and fast rule on these things.”
This year’s break in snow from late February into March was linked to an increase in tropical convection clouds over ocean waters off South Asia. When those clouds subsided, the snow returned, Miller said.
Warning signs for a bad winter appeared in December. Snow fell on 22 days that month, the same as in December 1968, Miller said.
But the maximum snow depth, on Jan. 31, was 20 inches. That’s less than half the snow – 42 inches – that piled up in 1969.
Probably the snowiest period in modern times came from the fall of 1948 through spring of 1952 when more than 70 inches fell four seasons in a row, including the all-time record of 93.5 inches in 1949-‘50. Another 83.2 inches fell in 1955-‘56.
Miller said a slow warm-up is expected next week, but no real springlike conditions are foreseeable until the week of April 6.