The last item in that list is certainly a different kind of weather extreme. But it's just as exciting, for me at least, to observe a thunderstorm roll overhead as it is to stand out in a day when the thermometer exceeds 100 degrees Fahrenheit, or when it drops below 0 degrees Fahrenheit.
And that's just what a large portion of the central and eastern United States experienced last week, especially here in the Chicago Metro Area, with temperatures like this not having been experienced in nearly 20 years, before I was paying much attention.
But first, permit me please to offer some technical scienctific talk on this event, especially in regards to the polar vortex, which many have heard about in news reports on this extreme cold. You can find a good scientific explanation of it in its entry in the American Meteorological Society glossary.
Basically, the polar vortex is one of many circulations of air that occur on a very large scale on the planet, found, as its name suggest, in the polar region. It contains bitterly cold Arctic air. But things can get interesting in winter, because of the upper-level atmospheric flow of air.
This flow of air is driven by the strong contrast in temperature between the cold poles and the warm Equator regions. In a basic world, the flow moves straight from west to east in the northern Hemisphere. But there are times when the flow doesn't act this way. It may start to bend into high points and low points. Where there's a low point, referred to as trough, cold air can surge from the pole toward the Equator, balanced out by a high point, or a ridge. In the case of what happened last week, it was some of the Arctic's coldest air that surged down into North America.
An area of low pressure moved through Chicagoland over the weekend of January 4-5, bringing some frozen precipitation on Saturday, and then a large amount of snow on Sunday. The low dragged a cold front through the area, and behind it, a large, an extremely cold air mass surged straight down from the Arctic. By 7 AM on Monday morning, January 6, the temperature had fallen to -16 degrees Fahrenheit (-27 degrees Celsius) at Chicago-O'Hare International Airport, having come from a temperature of -2 F (-19 C) around midnight Monday.
I didn't venture out much on that Monday. I went to Church in the morning. On the way, the clock/thermometer display at the Fifth Third Bank on Oak Park Avenue right by the I-290 showed -18 F (-28 C). The sky was so clear, and the sun shone nicely that morning. But that didn't do much to overcome the constant stream of strong northerly/northwesterly winds that brought that Arctic air into the region--something we call cold air advection in meteorology-speak--and made the already cold temperatures feel even colder. High pressure caused the skies be so clear, while the low that had brought the snow was close enough to cause the air to restrict the movement of airflow to induce strong winds. (I went out later, in the early evening, to pick up Mom from work.)
Being cooped up inside most of the day was what public officials recommended people do, so as not to be exposed to the dangerous cold, which came on top of a significant snow event the day before. That snow was exacerbated by the strong winds, which caused so much drifting, plows couldn't clear the roads, and vehicles got stuck. This was especially a problem in Indiana. Checking a map showing road condition alerts for Indiana counties on the Indiana Department of Homeland Security's website, the majority of Indiana counties were at a "warning" level. The South Shore Line, which I have used often going between home and ValpU, had to completely suspend service on that Monday.
The major travel problems were also plentiful in the Chicago hub, with bus, plane, and Amtrak train service experiencing disruptions to service, more so than I realized at first. Fortunately, for the many who were out on the roads in the harsh conditions, the Red Cross in conjunction with local churches set up shelters in central Illinois, at one of which the Ruggabers spent the night on their way back from Memphis. Those who set up the shelters are certainly owed a debt of gratitude.
I wasn't aware of all these situations with the roads until I watched a press conference early Monday afternoon with Governor Pat Quinn and other state officials, who briefed the press on the response to the extreme winter weather conditions on the roads. (I found it a bit odd that Ann Schneider, the Illinois Secretary of Transportation, referenced The Weather Channel's name for that winter storm. I would think that a government official would avoid using those names, as NOAA has discouraged any of its employees from using the names. I, for one, am not inclined to use them myself.) This press conference really emphasized for me the important role of elected officials in responding to hazardous situations, something I hope people keep in mind when they cast a ballot.
The temperature hovered in the negative teens range for the rest of Monday. The next day, Tuesday, the temperature started rising, and at the end of the WGN midday news broadcast, Tom Skilling announced the temperature had gotten back to 0 F (-18 C) at O'Hare, prompting applause sound effects. The winds also started dying down, so the Wind Chill Warning the NWS put out expired at noon. Despite being only in the single digits on Tuesday afternoon, it seemed like a major accomplishment that we had finally gotten into the positive side of 0 degrees F. Of course, therein lies the danger, as people perceive that the cold isn't as much of a problem anymore because it's warmed up to such a benchmark, and so they let their guard down. That's why one doctor who was interviewed said the hospital she worked at was expecting more cold-related cases to come in later in that week, after it warmed up a bit.
Temperatures continued warming through the week until reaching the 40s by the weekend, which, along with rain on Friday, helped melt the significant snowpack, which reflected the sun's energy on those very clear days, helping make it so cold. And you know, 40s is honestly not that warm if we really stop to think about it. But when I was out walking on Sunday in those temperatures, with melted snow and puddles everywhere, I couldn't help but think how spring-like it felt, as if it was March.
But that's the beauty of Chicagoland weather: We experience a whole range of temperatures, sky conditions, and precipitation events because we are in a mid-continental, midlatitude location. There's a certain kind of pride we can take in it, as expressed so well in this Chicago Tribune editorial. (Please note: I really like this editorial, and want to share it with you, my blog audience. But I regret that there's a picture which is partially racy appears at the top of the online version. Once the page opens, feel free to scroll down immediately to avoid looking at it.)
Honestly, it was enjoyable for me to have this experience of the extreme cold of January 2014, because of how it fits in to the larger picture of weather.
It all starts back in October, when the globe reaches that annual position when the Northern Hemisphere starts tilting away from the sun's most direct rays, and the northern polar region enters into deep winter darkness. With less sunshine, temperatures fall, which means the precipitation that comes down does so as snow. The snow on the amasses into a decent snowpack, reflecting the sun's energy away with its high albedo (measure of reflectivity), helping to form a significant cold air mass. Once the rest of the Northern Hemisphere cools with less and less sunlight, that cold of the Far North penetrates deeper toward the Equator, giving us our wintry conditions in the midlatitudes.
But for those of you who are not cold weather fans, never fear, because the time will soon come, and is already on its way, when the Earth reaches that annual position when the Northern Hemisphere tilts to have more exposure toward the Sun. The northern polar region experiences more daylight, and eventually warmer temperatures that melt the snow away, and allow temperatures to warm further. Soon, the warming is so great that there won't be much cold air to speak of, and it is truly summer.
Ah the seasons--what a beautiful cycle it is!
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| Here's the reading on a thermometer perched just outside the glass pane of the kitchen window on Monday afternoon. While not set up in the way to garner the most scientifically accurate reading, per NWS regulations, it does capture the cold temperature very well. It's also somewhat accurate because this window faces the north side of the house. |
Scenes of the cold, cold world outside from my bedroom window (top), and out the kitchen window looking back toward the alley (bottom):
As one more aside, I only regret I didn't go outside at any point on Monday to throw boiling water out to see what would happen. But I did do it on Wednesday night, after the temperature fell below 0 F. It was something to watch steam instantly arise from where the water landed, and see the little dribbles of ice that formed.
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