A storm to remember
A very unusual winter storm struck The County on the 24th of January, lasting into the wee hours of the 25th. What made it unusual was the exceptional amount of sleet it produced over a fairly good-sized hunk of Aroostook. An NWS employee told me that he’s never seen so much of it in one storm. He measured an astonishing, truly seldom-seen, 4.2 inches of sleet in Presque Isle (sleet is BB-sized pellets of ice).
If you were out that night, or early the following morning, it was quite likely your first time driving in inches-deep sleet! Just about all of the normal rules of winter driving, other than slowing down, were out the window! I likened it to a combination of driving in loose beach sand and millions of tiny ball bearings. At one point, going up a hill, I had my wheel hard left, to counter the pull of the “sand.” I’ve heard from folks who found themselves getting stuck in the oddest of ways, like making a simple right turn on level terrain, and then just having the car stop, as the tires would completely lose “grab”!
This all happened because the temperatures aloft were just right. At the surface, a sub-freezing layer, sufficiently deep for a raindrop to turn into an ice pellet existed, while at the same time, there was an above-freezing layer on top of that cold layer. That above-freezing layer aloft, melted falling snow flakes into raindrops, which then reentered the below-freezing air and turned into ice pellets.
Now when the surface sub-freezing layer is not deep enough, freezing rain falls instead of sleet. I think a better name for freezing rain would be “glaze,” since it glazes things over with ice.
Glazing occurs when the surface cold layer is shallow, and there is not enough time for the raindrop, which fell from the clouds as a snowflake, to have sufficient time to turn into an ice pellet, so it strikes the ground as water, and freezes on contact.
This is exactly what happened in New Brunswick, where heavy glazing, caused by the process just described, knocked down not only the power lines, but hundreds of power poles as well. Power outages were widespread, with disruptions most extensive in the eastern part of the province. Especially hard-hit was the Acadian Peninsula in northeast New Brunswick. For NB Power, it was their worst disruption on record, and thousands were without electricty for more than a week. It is their “Ice Storm of ’98.” If you’ve never heard of that, google “Ice storm of 1998.” That one crumbled huge transmission towers in the Eastern Townships of Quebec!
Getting back to what happened in The County, I’ve heard from a number of plow operators that it was the heaviest stuff they’ve ever had to move. And that weight, atop uncleared roofs, pushed some of those roofs past the breaking point.
Since the storm, all of that sleet has coalesced into a concrete-like layer of thick ice, in the upper part of the snowpack.
This storm was also notable for the amount of precipitation it produced. Caribou had a liquid equivalent of 1.70 inches. Looking at the satellite imagery that night, I could see the moisture that was feeding the storm, originating from the sub-tropics, south of the Bahamas!
Let’s wrap things up in this, our 68th get-together, (just naming the number, I’m not stopping!) by taking a look at our recently-concluded January. The singular weather event in northern Maine was, without question, the sleet storm. The singular weather period was the run of unusually mild nights from the 19th through the 29th, which featured one night that was 31 degrees above normal, and no nights any colder than 16 degrees above normal.
Given that mild stretch, I was rather surprised to see that Heating Degree Days came out quite close to December’s total. I had expected December’s total to be significantly higher, as I remember some very cold days.
As for snow, January had less than half of December’s total. 19.4 inches vs 41.2 inches. Looking at this winter vs last, it has been dramatically different! There’s been about three feet more snow in Caribou this year so far. In addition, unlike last year, this year the snow cover has been constant since the first flakes flew in earnest in late November.
Ted Shapiro holds the Broadcast Seal of Approval from both the American Meteorological Society and the National Weather Association. An Alexandria, Va. native, he has been chief meteorologist at WAGM-TV since 2006. Email him at firstname.lastname@example.org.