Last week’s cold front introduced cold air to many parts of the U.S., including Southern California and parts of the Deep South. On Wednesday, Jan. 16, for example, the mercury at Thermal, CA dropped to 25 degrees. This shattered the record of 27 set in 1963. Records at Thermal date back to 1950.
Perfectly fitting this chill was yesterday’s unofficial Penguin Awareness Day. Although Chase’s Calendar of Events doesn’t show it as an official day, the Bing search engine showcased penguins on its homepage on Jan. 20.
Still, if penguins lived across the northern Plains and parts of the Great Lakes (they actually live in Antarctica), they might just enjoy this week’s weather.
Brutally cold, wind-driven Arctic air has finally (after four years) invaded the U.S. Thanks Canada for sending it our way! However, the really cold air remains locked in with our northern neighbor. Saskatoon, Ont. reported a wind chill of minus 42 degrees early on Jan. 21. At the same time, Regina, Ont. shivered with a minus 43 wind chill and Yellowknife, NWT reported a minus 45.
Stateside, International Falls, MN earned its title of “The Icebox of the Nation.” A minus 22 reading, coupled with a stiff westerly wind yielded a wind chill of minus 44 shortly before sunrise on Jan. 21.
In fact, to the north of a line from western North Dakota to eastern South Dakota to northern Iowa to northwestern Wisconsin, wind chills were in the minus 25 to minus 40 range (Fig. 1). Even Chicago, IL logged a negative wind chill, while wind chills at Cleveland, OH and St. Louis, MO hovered near 10 degrees.
Hence, it is no surprise to find wind chill advisories and warnings across a large region of the northern Plains and central Canada.
Wind makes the cold feel even colder to exposed skin surfaces. In the absence of wind, a shell of slightly warmer air develops around a person. This helps insulate the body from losing additional heat. However, walking at a pace of about three to four miles per hour or standing still in a wind of four miles per hour or more removes that shell. The greater the flow of air past a person, the faster the person loses heat. This can quickly lead to frostbite or hypothermia depending upon the wind chill temperature and exposure period.
To refine the index, the Canadian and U.S. weather services updated the wind chill index computational formula back in 2001. Canada even employed human subjects to test the validity of the new index.
If you want to do your own wind chill computations, you can view this wind chill chart or its associated wind chill calculator. Check out the online wind chill brochure for wind chill safety tips, too!
Another key component of this bitterly cold outbreak involves lake effect snows. The air moving across the Great Lakes is so cold, while the lakes are so warm and unfrozen for this time of year (Fig. 2), that convective cloud bands filled with locally heavy snow showers and squalls have developed. The bands tend to be locked in one place for extended periods due to the persistency of the winds and the sometimes lengthy over water trajectory. This produces narrow bands of heavy snowfall, while nearby areas may have no snow or even clear to partly cloudy skies.
Already some places near Buffalo, NY (e.g., Palermo and Pennellville) have netted more than half of foot of lake effect snow; one to two additional feet are expected in local preferred areas downwind from the Great Lakes during the next few days.
Also, wind driven waves, crashing shore have prompted the issuance of freezing spray warnings (Fig. 3). Localized whiteout conditions due to snow and blowing snow can be anticipated, as well.
As if the cold, wind and lake effect snows are not enough, a weak storm system currently moving through the eastern Great Lakes is expected to rapidly deepen today and tonight, almost to “meteorological bomb criteria" (Fig. 4). Widespread three to six inches of snow is expected across much of New York and New England; some coastal areas from Cape Cod northward may net six to 12 inches of whiteness by noon on Tuesday.
By the end of the workweek, another storm (Fig. 5) is expected to spread snow across a wide area from the central Mississippi River valley into New England.
All the while, Arctic / Siberian air will keep infiltrating the Great Plains, the Great Lakes and much of the northeastern quarter of the Nation (Fig. 6). Modified, albeit quite chilly air will spread into the Deep South. Only Florida and the Southwest will escape the full cold air onslaught.
© 2013 H. Michael Mogil
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