Image credit: National Weather Service, Twin Cities/Chanhassen
An unusually active period produced several distinct rounds of thunderstorms and heavy rainfall across Minnesota from June 15th through the 22nd, leading to widespread nine-day totals of 4 to 8 inches across different parts of the the state, with pockets of totals ranging 8-11 inches in southern and southwestern areas. The rains produced significant flooding across both northeastern and southern Minnesota.
The first slug of heavy rains developed on Saturday June 15, lasting into the Sunday June 16. This rainfall hit parts of central Minnesota to the west of the Twin Cities the hardest, with totals of 3 to5 inches reported in southern McLeod and Sibley counties. A widespread area from the northern Twin Cities down to the Iowa border received 1-2 inches.
More heavy rains moved in Sunday night and Monday (June 16th and 17th), producing totals of one-half to two inches across mostly central and southern Minnesota.
A major rainfall event then struck northern and northeastern Minnesota on Tuesday June 18. Thunderstorms first raked central, western, and northern Minnesota early on Tuesday June 18th. Strong to thunderstorms with torrential rains then redeveloped across northern, central, and parts of southern Minnesota Tuesday afternoon and evening. A wide area from Walker to Grand Rapids, northeastward to the Canadian border and eastward to the the shore of Lake Superior, received at least three inches of rain, with many areas seeing 4-6 inches and several locations reporting 6 to almost 8 inches of rain. This was one of the largest rains on record in northeastern Minnesota, and produced extensive flooding and damage from the Iron Range and Lake Vermilion to communities near Lake Superior.
After a break during most of Wednesday June 19, a major extreme rainfall and flood event hammered southern Minnesota for parts of three days, from Thursday June 20th into Saturday June 22nd. Thanks to waves of intense rains on Thursday night into Friday morning; Friday afternoon; Friday night and Saturday morning; and a top-off of moderate to heavy rain on Saturday June 22nd, much of far southern Minnesota received 6-9 inches of rain, leading to major flooding of communities, rivers, and farms.
The parade of heavy rainfall events from June 15th to the 22nd led to 9-day totals of 4-11 inches across southern Minnesota and 4-7 inches across the northeast. Over 50% of the state received three inches or more and 85-90% of the state received at least two inches of rain. The highest rainfall total was 11.69 inches, recorded by the National Weather Service cooperative observer in Windom. A CoCoRaHS observer near Mankato record 10.76 inches and the cooperative observer at St. James recorded 10.61 inches. Virtually the entire area from Faribault to Mankato to the southwest corner of the state received 8 inches of rain or more during this stormy and wet period. Totals at Minnesota's five "first-order"observing stations included 6.49 inches at Rochester, 4.12 inches in the Twin Cities, 2.71 inches in Duluth, 2.23 inches at St. Cloud, and 1.88 inches at International Falls. Normal monthly precipitation for June ranges from about 3.25 inches in the far northwest to over 5 inches in the southeast.
June 25, 2024
KAB