The nation's weather A cold front over the Southeast will advance eastward and move offshore by midday Sunday. Expect showers and thunderstorms - and possible high winds - along and ahead of the cold front from the Mid-Atlantic Coast to the Florida Peninsula early Sunday. Showers and thunderstorms will ebb late Sunday morning as the front departs. Farther north, another cold front will move through the Great Lakes and Northeast, producing scattered snow showers. In the nation's mid-section, a fast-moving system is expected to drop across the Northern Plains and the Mississippi Valley, reaching the Ohio and Tennessee Valley by Sunday night and early Monday. This system will scatter a mix of rain and snow along its path. Out West, a frontal system will remain near the Canadian border. Strong moist onshore flow associated with this system will trigger light to moderate rain and high-elevation snow to western Washington state. This front will slowly move southward across the Oregon coast by Monday morning. Over the Rockies, snow showers will continue mainly through Sunday morning. Temperatures in the lower 48 states ranged Saturday from a morning low of -5 degrees at Monarch Pass, Colo., to a high of 90 degrees at Ft. Pierce, Fla. Weather Underground: http://www.wunderground.com National Weather Service: http://iwin.nws.noaa.gov Intellicast: http://www.intellicast.com