Pothole Prairie, by Tim Engstrom

This winter is a bad one. Just how bad is it?

Paul Douglas, a meteorologist who writes for the Minneapolis Star Tribune, wrote last week that Minnesota officially is in the 10th coldest winter on record. He said it is the coldest winter since 1979.

By the way, he is measuring with meteorological winter, which is December through February. That’s right. Winter is over, according to their calendar, but look out any frosted window and the story says otherwise. When the outdoors looks like a tank freezer left on the coldest setting and unopened for three months, it’s still winter in my book.

Say, that’s an idea. Shouldn’t there be a way to measure the official start and end to a season not by dates on a calendar but by a set of weather conditions? Winter would be officially over when A. roads are no longer paved with compacted snow B. brown grass is visible C. new snow soon becomes slush D. high temps are above freezing for at least seven days in a row E. people wear light jackets instead of winter coats F. kids shoot hoops at outdoor basketball courts.

By the way, the winter that lasts from Dec. 21 to March 19 this year in the northern hemisphere is known as astronomical winter.

It was interesting to read the region’s snow depths last Wednesday. Albert Lea was listed at 15 inches. I decided to look up our record snow depth, with snow depth records going back to 1899.

The answer is 38 inches on Jan. 23, 1982. Several records came that year. The No. 2 record was 35 inches on Jan. 24, and No. 3 was 32 inches on Jan. 25. No. 4 was 30 inches on Feb. 19, 1967. That was tied with March 17 and 18, 1917.

I’ll tell you what. (I’m in Texas as you read this, so I needed to say that.) The next time we have to shovel the canyon-looking sidewalks, don’t tell me the snow depth is just 15 inches. Thanks to the snow pushed to the curb by snowplows on one side and to our yards by our own snowblowers on the other, the depth for many homeowners is in the range of 24 to 36 inches.

(In Texas, there is no snow today. Jealous?)

One of our loyal readers wants to know where the term “ground blizzard” comes from. He said, “Isn’t that the same thing as blowing snow?”

Apparently, ground blizzard is a meteorological term for a weather phenomenon that happens more frequently up in Canada than down here on the plains of southern Minnesota. It is like blowing snow, but it has intense winds and snow drifts that create blizzard conditions without falling snow.

The National Weather Service’s glossary defines it this way: “When blizzard conditions are solely caused by blowing and drifting snow.”

Personally, the meteorologists this winter are trotting out several previously unheard terms from their weather dictionary. Who had ever heard of a polar vortex until January arrived? Some are calling the deep freeze we are in a cold wave, as opposed to a heat wave. And what in macadamia nuts is bombogenesis?

Yes, a meteorologist in Philadelphia on Jan. 21 dropped that bomb to describe a large, fast-moving snowstorm headed for the East Coast. Then the word spread.

A bombogenesis, according to writer Angie McPherson at the National Geographic Society, “is a slang word used by meteorologists to describe a winter storm that forms quickly.” The word originates from “cyclogenesis.” The bomb part comes from how the barometric pressure drops swiftly.

McPherson said a polar vortex is a wind pattern over the north and south poles. We hear it only when it dips low enough into our country. That typically happens when the jet stream weakens, allowing the polar vortex to venture south.

She also described another unusual weather term in use this winter, “williwaw.” The word dates back to the 19th century, but its origin is unknown, she said. It is a violent windstorm created when gravity pulls cold air from a mountain to the sea, common in Alaska. These types of winds are katabatic winds. A famous katabatic wind is the Santa Ana winds in California, known for fanning wildfires in the dry season.

Why do these meteorological terms spread so fast these days? The answers are simple — social media and the Internet. In the olden days, when a forecaster uttered an interesting weather term in one city, few in other cities ever heard it. Now, everyone gets wind of it.

 

Tribune Managing Editor Tim Engstrom’s column appears every Tuesday.