Texas and the Southern Plains also receive their fair share of winter storms. A typical scenario begins with a strong cold front moving down the eastern slopes of the Rocky Mountains. As this front moves into the Texas panhandle, winds switch to the north and temperatures drop markedly.
Locals in the panhandle call this weather event a blue norther, referring to the blue-black sky that often accompanies these storms.
A blue norther brings cold air to Texas. The situation is complicated when moist air is present farther south in Texas, accompanied by upper winds out of the southwest or west. As the surface cold front continues to push southward, it undercuts the warm, moist air near the earth's surface.
The cold front slows or perhaps remains in a stationary position. This can result in an extended period of wintry precipitation, usually in the form of freezing rain or sleet caused by a shallow cold air dome near the ground.
The effects of a blue norther could be seen on Thanksgiving Day, 1993, when the Dallas Cowboys played football at Texas Stadium in the midst of a sleet storm. In January 1985, San Antonio experienced unusual weather in the form of snow and sleet, spurred on by the effects of the cold front.