National Weather Service United States Department of Commerce

Heavy Rainfall, Flooding, And Severe Thunderstorm Threats From The Mid South To The Great Lakes Today And Tonight

A slow moving low pressure system and cold front will bring the potential for severe thunderstorms capable of producing damaging winds and isolated tornadoes from portions of the Mid South to the Midwest and Great Lakes today and tonight. Heavy rainfall could also lead to flooding concerns. The severe weather threat will shift to the Mid Atlantic and Northeast on Wednesday. Read More >

Do you have any pictures of flooding from this summer? Or pictures of changes in lake levels across northern Wisconsin? We would love to see them! Email us at

The summer of 2010 will go down as a very wet one in northwest Wisconsin, with above average rainfall across most of the Northland. Quite a few rounds of thunderstorms and heavy rain started affecting the area in May, and continued through September. Things have quieted down some in the last week of September and the first few days of October.

As a quick illustration of the rainy summer, consider the following:

  • Duluth had its rainiest calendar day on record on May 23, 2010 when 3.93 inches of rain was recorded.
  • For the period May-September, Winter, Wisconsin set a rainfall record, shattering the old record by over 5 inches. 36.78" of rain fell from May 1 to September 30 in 2010, beating the old record of 31.55" in 2002.
  • Other cooperative observer stations that set a record for rainfall between May 1 and September 30 were: Park Falls, 5E Cook, and Kabetogama. Duluth came in 5th place, International Falls 3rd place, Gurney 3rd place, Gordon 3rd place, 7 ENE Bruno 3rd place, Deep Portage 3rd place, Hinckley 2nd place, Grantsburg 2nd place, Solon Springs 2nd place, and Littlefork 2nd place on their respective lists for the same time frame.

To keep the numbers in perspective, note that most of northwest Wisconsin only averages 30 to 32 inches of precipitation for an entire year, and more rain fell in a span of 5 months in most of those areas this summer.

This rainfall was especially notable because of the extended period of drought and rainfall deficits that had plagued northern Wisconsin for the past few years. Below is a graph of a running rainfall surplus/deficit starting at the beginning of 2003 at Winter, Wisconsin. You can see that an extended period of rainfall deficits took hold in 2004, and lasted through the early part of 2010, before rebounding sharply this summer.

Because of the abundant rainfall this summer, many of the lakes and bodies of water that had been running much lower than normal are reported to be at levels closer to normal across most of the area.

Notes: the map at the top of the page was created using NWS cooperative observer network rainfall data and GIS software. The contoured colors are interpolated from the point data, and may not necessarily represent the actual observation at each point, but should be a fairly good estimate across the entire area.