A series of Pacific storms is taking aim at the Northwest this week, delivering heavy rain, mountain snow, and gusty winds that could lead to flooding. While the West braces for more moisture, the Central and Western U.S. will bask in record-challenging warmth, with temperatures soaring 15 to 25 degrees above normal. Meanwhile, the chill that's gripped the Eastern U.S. finally begins to ease midweek, ushering in a brief break from the Arctic air. Flash freeze, snow, and wind will hit much of the Canadian Prairies, first with Alberta on Wednesday, then spreading eastward.