Blue Norther on the horizon

"Blue" Norther on the horizon, 5 x 7 watercolor

"Nothing between us and the North Pole but a barb wire fence, and two strands of that are down."
So was our joke a few years ago as a "blue norther" swept through rural Oklahoma, plunging temperatures into the teens in a matter of minutes, with a biting wind chill to boot.
If you live any time on the Great Plains, you have experienced a blue norther sometime in your life.
Most memorable for me was several years ago, driving on a clear day through the Texas Panhandle toward New Mexico.
But up ahead, I could see this dark wedge against the northwest sky. Almost within sight of Amarillo, the ragged dark gray edge of clouds, ahead of dark blue gray on the horizon angled toward me.
 In a few minutes, I was pelted with sleet and freezing rain, and Interstate traffic slowed to a crawl. I saw jackknifed trucks within a mile or so. Instead of making it to Santa Fe by nightfall, I stopped, ate, watched the weather get worse outside. I managed to get to Tucumcari for the night.
Blue Norther? I looked it up. It's a  a fast-moving cold front that causes temperatures to drop dramatically and quickly. Common characteristics are a dark blue-black sky, strong winds, and temperatures than can drop 20-30 degrees Fahrenheit in a few minutes.
Ironically, they are commonly associated with the Texas Panhandle, and are sometimes called Texas Northers, though they occur elsewhere on the Great Plains.

The Texas State Historical Association reports that  the term "Blue Norther" has at least three attributions:
"The term refers, some say, to a norther that sweeps 'out of the Panhandle under a blue-black sky'—that is, to a cold front named for the appearance of its leading edge. Another account states that the term refers to the appearance of the sky after the front has blown through, as the mid-nineteenth-century variant 'blew-tailed norther' illustrates. Yet another derives the term from the fact that one supposedly turns blue from the cold brought by the front."

The National Weather Service in Amarillo notes that Blue Northers can catch people off guard. Temperatures can drop as much as 40 to 60 degrees within hours. Many times the temps will be unseasonably mild before hand, but they can happen anytime from late fall to late winter.

One of the most historic blue northers occurred Nov. 11, 1911. Some say it was among the most sudden and dangerous cold blasts in American history.

Cities in the Midwest experienced record highs in the 70's and 80's. By evening, temps in these same cities would drop into the single-digits, recording their record lowest temperatures.

In early afternoon,  the blue norther  blanketed cities like Kansas City and St. Louis will dark blue skies and low clouds.  By late afternoon, thunderstorms and hail began, and the temp began to drop. In Columbia, Mo., in one hour it fell from 82 to 38. By evening, driving rain, sleet, hail, and tornadoes gave way to snow and temps reached single digits. 
(Most of this is from an online web site.)
Speaking of blue, I use more blue colors in painting than any other. This one, is all with Ultramarine, and a little umber. It fits the subject.