A warm front extended east to west across the Upper Mississippi Valley on June 7, which provided the focus for thunderstorms producing excessive rainfall. In fact, these storms exhibited very high rainfall rates, which led to 1 to 2 inch rainfall amounts in an hour or so. As the storms congealed into a larger scale line of thunderstorms, they continued to move over the same areas, which led to significant flash flooding through the evening and overnight.
On June 8, the warm front was lingering across the region, but a cold front was quickly tracking east out of the northern Plains. Showers and storms would redevelop during the day in the vicinity of the warm front, while a line of storms developed out ahead of the cold front, with these tracking across the region Sunday night. Again, copious amounts of moisture lead to periods of heavy rain.
The heavy rainfall on June 8 enhanced the already dangerous flooding conditions across parts of southeast Minnesota. Many roads were already closed from the June 7 rains due to water over the roadways, mudslides, or partial washouts. Conditions only worsened, leading to more road closures, sandbagging, and some evacuations.
While the rain was tapering off and moving east Sunday night, June 8, the rivers continued to rise, and some extremely quickly. Some rivers responded with a foot per hour rises. A top 5 record crest was set at the South Branch of the Root River at Preston.
Fillmore, Houston and Mower County were declared federal disaster areas. Damage to crops and infrastructure in these locations was preliminarily estimated at 25 to 35 million dollars.

Flood in FILLMORE, MINNESOTA
From 08-JUN-08 07:30:00 to 10-JUN-08 09:00:00 (CST-6)
Location: SPRING VLY
Flood cause: Heavy Rain
Property damage: 2.10M
Crop damage: 1.80M
Reported by: Law Enforcement

Flooding was reported over the southern half of the county. Roads that were closed due to high water included Highway 63 in Spring Valley and County Highway 15. A rainfall total of 7.25 inches was recorded for the weekend of June 7-8 in Harmony where over 100 basements flooded. There were nearly 300 homes impacted in the county along with contaminated or collapsed wells.  Other county roads closed due to high water included 17, 12, 30, and 8.  In Preston, 12 business were affected and the city waste water treatment plant was flooded.  Some evacuations were needed in Preston, along with Lanesboro.

Flood in HOUSTON, MINNESOTA
From 08-JUN-08 07:30:00 to 10-JUN-08 09:00:00 (CST-6)
Location: BLACK HAMMER
Flood cause: Heavy Rain
Property damage: 6.50M
Crop damage: 5.50M
Reported by: Law Enforcement

Widespread flooding forced the closure of virtually all roads across the county. Several civil emergency messages were sent by request of county officials for evacuations in mainly the southern half of the county. An estimated 9300 acres of corn and 5400 acres of beans were lost. There were massive mudslides in some parts of the county, just like in August 2007. Debris backup was common against area bridge supports.

Flash Flood in WINONA, MINNESOTA
From 07-JUN-08 16:30:00 to 07-JUN-08 19:30:00 (CST-6)
Location: LAMOILLE
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 10.00K
Reported by: Emergency Manager

Flash flooding led to mudslides and damage to sections of County Road 9 along Cedar Creek. Pleasant Valley Creek also had a flash flood. Water flowed into nearby fields as well.

Flood in HOUSTON, MINNESOTA
From 09-JUN-08 14:30:00 to 10-JUN-08 19:00:00 (CST-6)
Location: PERKINS
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 25.00K
Reported by: River/Stream Gage

The Root River went above flood stage across northern parts of Houston County for a day or two. The crest at Houston was 16.13 feet and the flood stage is 15 feet. Another crest occurred on June 14th of 15.26 feet.

Flood in WINONA, MINNESOTA
From 07-JUN-08 15:38:00 to 07-JUN-08 19:00:00 (CST-6)
Location: WINONA
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 20.00K
Reported by: Emergency Manager

Street flooding was reported in Winona.

Flash Flood in HOUSTON, MINNESOTA
From 07-JUN-08 19:30:00 to 08-JUN-08 07:30:00 (CST-6)
Location: NEWHOUSE
Flood cause: Heavy Rain
Property damage: 2.50M
Crop damage: 1.50M
Reported by: Trained Spotter

Very heavy rain led to flash flooding through much of the county. A rainfall total of 7.18 inches was measured 3 miles southwest of Reno. The bridge over Clear Creek was reported damaged and unsafe for use. In addition, highway 26 was closed due to mudslides. County Highways 5, 23, 31 and 249 were closed due to high water and washouts.

Flash Flood in FILLMORE, MINNESOTA
From 07-JUN-08 18:54:00 to 08-JUN-08 07:30:00 (CST-6)
Location: MABEL
Flood cause: Heavy Rain
Property damage: 750.00K
Crop damage: 500.00K
Reported by: Law Enforcement

Flash flooding impacted a large part of the county, especially the southern half. High water was reported over Highways 30 and 44. Many area creeks rose very rapidly and caused infrastructure damage.

Flood in FILLMORE, MINNESOTA
From 08-JUN-08 14:00:00 to 09-JUN-08 20:00:00 (CST-6)
Location: LANESBORO
Flood cause: Heavy Rain
Property damage: 750.00K
Crop damage: 800.00K
Reported by: River/Stream Gage

The Root River went into flooding due to the heavy rains during the weekend of June 7-8.  The South Branch of the Root River at Preston crested at 941.67 feet on June 9, which was the third highest crest on record. Flood stage is 937.0 feet.  At Lanesboro, the South Branch of the Root River reached 14.17 feet with a flood stage there of 12 feet.

Flood in OLMSTED, MINNESOTA
From 08-JUN-08 05:30:00 to 08-JUN-08 07:30:00 (CST-6)
Location: VIOLA
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 15.00K
Reported by: Law Enforcement

Highway 56 became flooded after additional rounds of thunderstorms moved through.

Flash Flood in MOWER, MINNESOTA
From 07-JUN-08 17:00:00 to 08-JUN-08 07:30:00 (CST-6)
Location: LYLE
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 300.00K
Reported by: Law Enforcement

Hardest hit by flash flooding were locations in the southern part of the county, including the communities of Adams and Lyle.

Flood in MOWER, MINNESOTA
From 08-JUN-08 07:30:00 to 10-JUN-08 09:00:00 (CST-6)
Location: AUSTIN ACRES
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 400.00K
Reported by: Law Enforcement

Numerous roads were closed due to high water, especially over the south part of the county near the Minnesota-Iowa state line. Creeks ran very high in Austin area.