A deep upper low will bring heavy mountain snow and windy conditionsacross a large portion of the western U.S. through the next couple ofdays......A slight chance of severe thunderstorms across Texas and upper Midwestinto Sunday will shift into the central Plains by later on Monday......Critical fire danger is forecast for the southern Rockies...A rather vigorous and deep upper-level low currently approaching the WestCoast will result in the next wave of active and stormy weather to quicklysw...