Winter, ad infinitum 2014.02.12

Written by David Green. Posted in Feature Stories

front.ice copyBy DAVID GREEN

There's not much science in measuring snow depth, says Morenci's climate observer George Isobar. Instead it's often more a matter of guessing.

"I can tell you how much precipitation fell," he said. "You dip a measuring stick into the rain collecting can, and in the winter you often have to bring it into the house to first melt the snow and ice and then measure. But snowfall? That's a different matter."

Especially with the wind that's been accompanying most of our snows this winter.

"It might be 12 inches deep in your back yard," Isobar said, "but try the front yard. There might be only three inches there."

People often jump to conclusions after a snow, he said, and think there's more than what really fell.

"I could tell you we had 16 inches of snow on the ground last week, but there's probably somewhere in your yard where it's 20 inches deep. And another where it might be 10 or less."

In these cases, Isobar and other members of the National Weather Service Cooperative Observer program have to walk around an area and take an average of the depths they measure.

Isobar received a note recently from his predecessor, Tom Buehrer, who now lives in Florida. Since many people are comparing January 2014 to that of 1978, Tom sent some recollections of the great blizzard when, by the way, Isobar was not living in Michigan and missed all the winter fun.

"I remember walking home from school wondering when it would change to snow and noting how ominous the sky looked," Tom wrote. "By evening, I knew there would be no school on Thursday."

Nor was there school on Friday and the entire next week. Fortunately, there weren't many windy days after the storm or all the rural roads, looking like small canyons, would have filled again.

Sometimes even the melted precipitation total might be a little shaky, Tom pointed out.

"The wind was high enough to exhibit a Bernoulli effect on the rain gauge," said the retired science teacher.

Bernoulli effect? As one text describes the phenomena, the Bernoulli effect creates a decrease in air pressure above the gauge, causing precipitation to fall away from the gauge.

"I think more snow was sucked out than stayed in," Tom said. "Trying to average the snow depth was a real chore. First, my clip board was in danger of blowing away. Second, after going about 100 feet I couldn't see the apartment building. I could understand the old stories of farmers becoming lost going to the barn."

Tom ended up figuring an average snow depth of 22 inches from that storm—a good share of the month's total of 34.7 inches.

Although January 2014 came close to matching 1978—30.2 inches measured—the big difference this year is that snow fell during three significant storms rather than one big dumping.

"Early in the month 8.6 inches fell, then after a break of two days, another 7.8 inches came," Isobar said. "A January thaw came in the middle of the month and the depth on the ground shrunk from 13 inches to three."

After the thaw, some snow fell almost most every day, and starting Jan. 25, another 6.9 inches arrived over three days. 

"That's a pretty hefty total for this part of the country," Isobar said, "and it just keeps coming. We've had more than 13 inches so far in February and we aren't yet halfway through the month. Some years we have a pretty good snowfall in March."

Isobar said there have been four 20-inch-plus Januarys in the past 40 years before this one, with the latest in 2005. There have also been two years with nearly 23 inches in February—2008 and 2011.

"Our total so far stands at about 55 inches for the season," he said. "It won't do you any good to complain about it. You might as well enjoy it and know that you have something to tell the grandkids about."

And Isobar had one other thing to mention.

"Yes, it's a lot of snow for us, and yes, we've had an unusually large number of sub-zero days," he said, "but I will probably get a note from former Adrian resident Charles Lindquist in Escanaba telling me what a real winter looks like and feels like."

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