Hate the snow that is making driving and walking a true effort? Dislike the bone-chilling cold that has been a regular visitor?
Better get used to it because this LA Nina winter does not appear to be going anywhere too soon says retired Eastern Washington University professor and weather expert, Bob Quinn.
“The storm track, since we’re into mid-winter, normally drops to the south, so that’s what it’s doing,” Quinn said. It is centered around Northern California and Oregon and the Inland Northwest is on the northern periphery, or as is referred to as, “The cold side of the jet (stream).”
“The end result is that it’s a pretty favorable pattern for snow,” Quinn said.
The big storms have been pounding California an Oregon with feet of snow — up to 5 feet around the shores of Lake Tahoe, and well over that in the higher elevations of the Sierra Nevada — and buckets of rain, quenching the thirsty region that has been saddled with drought for years.
“They have had almost record amounts of precipitation down there,” Quinn said.
And as of Jan. 9, our area has had just shy of 33 inches of snow, well on the way to equaling or surpassing the yearly average of 45 inches.
“What’s going to happen is we’re going to continue this pretty active Pacific storm track, which will be back and forth,” Quinn said.
It will move its center to the south and the Pacific Northwest will remain on the cold side of the “jet,” with the spin-offs being pulses of moisture that give the region 1-2 inches of snow.
“While it doesn’t result in great big monster snowstorms, slowly but surely it mounts up,” Quinn said. The first measurable snow came Nov. 16 with .7 inches according to the National Weather Service.
The pulses will generally serve up a quarter to a half inch of moisture. How does that equate to snow?
“Snow-water equivalents are highly variable, depending on temperature where the snow’s forming,” Quinn said.
With an atmosphere that’s single-digit or colder there is still the possibility of snow, with the water value at 30-to-40-to-1 he said. That means it takes 30-40 inches of snow to get an inch of water.
Normal snow forming temperatures of 24 to 32 degrees, the ratios are 4-to-10-to-1. “A good average 8-10 inches of snow would equal 1 inch of water,” Quinn said.
The extended forecast keeps the storm track aimed at British Columbia with the Inland Northwest on the southern edge. What lies ahead then is a march of little disturbances every 48-72 hours dropping between 1-3 inches of snow.
This winter, which began, calendar-wise at least on Dec. 21, has also been colder than usual, and that, too, has the jet stream as the culprit.
When the jet stream dips south, it allows the outbreak of arctic air.
“It doesn’t end up being a blaster or anything but it ends up being a couple of days of that cold, single-digit-type arctic air,” Quinn said.
The track shifts north and the process begins over again with more snow and near normal temperatures.
“I don’t see a monstrously cold pattern or a monstrously Pineapple Express pattern so I think what you see is what you’re going to get,” Quinn said.
Paul Delaney can be reached at firstname.lastname@example.org.