I've seen some rough cold fronts, but in the last 24 hours the folks in northeast Wyoming have had a doozy. Here's the latest U.S. temperature-change map from Unisys:
The temperature in Gillette, Wyo. (right near the big "L" on that map above), fell from 6°C (43°F) at 5pm local time (00:00 UTC) yesterday to -19°C (-3°F) at 4pm (23:00 UTC) today, a rather alarming drop of 26°C* (46°F). Let's not forget the wind chill: with 26 km/h (16 mph) winds, it feels like -31°C (-21°F). At that temperature even Parker's big Labrador friends might stay home.
Astute readers may notice that the ball of fun on the map is headed east, which promises to make this weekend in Chicago a good one to sit by the fire and open the door only enough to let the dog out (regardless of what the neighbors think).
* This is correct; all the numbers are rounded, so the integer math doesn't work right.