Meteorological Synopsis
Very warm, humid, summertime air had pushed into central on southern Minnesota on August 6, 1969. Minneapolis saw a high temperature of 93 °F (34 °C) with dew points near 70 °F (21 °C). Meanwhile, strong upper-level winds over northern Minnesota and an approaching cold front from the west added the needed ingredient for the strong storms.
Read more about this topic: 1969 Minnesota Tornado Outbreak