Keystone, SD

Weather Underground Forecast for Monday, February 13, 2012.

The trough of low pressure that brought unsettled weather to the West on Sunday will advance into the Plains on Monday with more mixed precipitation. The trough will support a low and associated warm front moving eastward into the Southern Plains. As the system progresses, rain showers with periods of heavy rain and isolated thunderstorms will spread from parts of central/eastern Texas into western Louisiana, mixed precipitation will develop in parts of Oklahoma and Arkansas, and snow will blanket parts of the Central Plains, Mid-Mississippi Valley, and parts of the western Ohio Valley. Areas from eastern Texas through Arkansas should expect the heaviest precipitation totals. Heightened winter weather conditions will allow Winter Weather Advisories and a few Winter Storm Warnings to remain in effect through the day. Elsewhere east of the Continental Divide, lake-effect snow showers will continue along parts of the Lower Great Lakes Snowbelt.

In the West, a Pacific cold front pushing across the Pacific Northwest will drop southward across northern California, bringing coastal and valley rain and significant snowfall to the Sierra Nevadas.