Heavy Rains Fall on Iron Range:
September 6, 2007

rainfall map


A strong upper level disturbance, interacting with a frontal boundary that bisected Minnesota, brought extraordinarily heavy rain to northeastern Minnesota on Thursday, September 6. Rainfall totals topping six inches were reported in central St. Louis County and portions of Lake County. Rain amounts exceeded eight inches in an area just to the north of Virginia. A few locations south of Tower and near Babbitt also reported eight-inch totals. The most intense rainfall occurred during the late afternoon and early evening hours of the 6th, with rainfall rates exceeding one inch per hour in some locales.

The deluge led to overtopped or washed out sections of township roads in central St. Louis County and in Lake County. The public reported a section of Highway 1 near Ely was washed out. Some flooding was reported along Bear Creek north of Embarrass. The situation was greatly tempered by the long-term drought conditions that existed prior to the rain event. A storm of this magnitude and intensity would have certainly had a greater impact had the landscape not been so dry. A six-inch rainfall total for a given location in this region over a 24-hour period is said to be a "100-year" (1% probability) storm.

Technical Information:

  • A list of the 181 data points used to generate the map above is available as a comma-separated text file. The values are x and y UTM coordinates (Universal Transverse Mercator projection - NAD83, zone 15), followed by a precipitation total in inches.
  • Heavy Rainfall Event Climatology

A Word of Thanks:

The State Climatology Office thanks the North St. Louis Soil and Water Conservation District, the National Weather Service, DNR Forestry, and all of the diligent volunteer precipitation observers who make analyses of these events possible.

For more information contact: [email protected]

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