The Great Blue Norther of 11/11/11

It starts as a wisp of white cloud on the horizon of a blue sky. A thin line of blue-gray storm clouds soon fills the northern sky, racing southward. Texans know a blue norther is on the way.

Texans will tell you that everything in Texas is bigger, even their cold fronts. The powerful cold waves sweep southward out of the Texas Panhandle, causing dramatic drops in temperature. A true blue norther is an impressive phenomenon. They happen when intense cold high pressure builds up over Canada and spills rapidly southward across the treeless Plains. With no mountains to impede them, the fronts surge southward at speeds of up to 70 mph and higher.

The rapidly -moving line of dark blue and gray storm clouds soon overspreads the entire sky, followed by fits of rain and an increasing wind. Behind the front, winds turn around to the north and the temperature drops quickly.

The origin of the term “blue norther” is unclear. It may stem from the blue skies and extreme cold that typically follow the fast moving fronts. Another explanation is that the name comes from the blue-black line of storm clouds that races in advance of the cold wave. Some say it is because the cold airmass turns people blue.

On this date in 1911, one of the most powerful “blue northers” in American history was sweeping south across the Plains. The temperature contrasts across the front were incredible. Kansas City, Missouri recorded a temperature of 68 degrees while less than four hundred miles away, the temperature at North Platte, Nebraska, was only 4 degrees above zero at the same time.

Kansas city recorded a high temperature for the day of 76 by late morning, but the temperature then began to drop and it was snowing by early afternoon. By midnight the temperature was 11 above zero. Oklahoma City recorded a record high (83) and a record low (17) on the same day. At Independence, Kansas the temperature dropped from 83 to 33 degrees in one hour!

An F4 tornado killed 9 and injured 50 in Janesville, Wisconsin. An hour after the tornado, survivors were digging through the rubble in zero degree temperatures and blizzard conditions.

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Category: Met 101/Weather History