Why is it so hot in March?

Jeff Masters writes at his "wunderblog," the Weather Underground: The ongoing March heat wave in the Midwest is one of the most extreme heat events in U.S. history. With so many records being shattered, it is difficult to cover in detail just how widespread, long-lasting, and extreme the event is, and I offer just a few highlights:Winner, South Dakota hit 94°F yesterday, the earliest 90°+ reading ever recorded in the Northern Plains, according to wunderground's weather historian, Christopher C. Burt. The 94°F reading was just 2°F short of the all-time state record for South Dakota in March, which was 96°F in Tyndall in 1943.International Falls, Minnesota hit 79°F yesterday, the hottest March temperature on record in the Nation's Icebox. At midnight this morning, the temperature was 66°F there, breaking the record high for March 19 (set in 1910) by 6°F. The low temperature for International Falls bottomed out near 60°F this morning, so low for today is...(Read Full Post)