A major weather pattern shift is set to occur across the country, with a record-setting Western heat wave expected to settle in while winterlike cold returns to the East. The heat wave is expected to dominate weather headlines for at least two weeks, with numerous locations expected to set all-time heat records for March. The West's already below-average snowpack will melt, raising concerns for spring and summer water resources and a potential severe wildfire season. The National Weather Service has warned residents of the Southwest to prepare for potentially deadly March temperatures. This follows what was already the West's hottest meteorological winter on record.