Another night in the long duration heat wave brought another round of nocturnal convection. Early in the morning of the 19th, a weak surface boundary set up across northern South Dakota into west central Minnesota. As the low level jet and warm advection increased after midnight, thunderstorms began to fire. The air mass was extremely unstable with precipitable water values over two inches. The thunderstorms moved very slowly, and with the high amount of available moisture, heavy rain and flash flooding were also an issue.

Thunderstorm Wind in CLAY, MINNESOTA
From 19-JUL-11 03:42:00 to 19-JUL-11 03:42:00 (CST-6)
Location: MOORHEAD ARPT
Magnitude: 55.00 MG
Reported by: Mesonet

The wind gust was measured by a MNDOT RWIS sensor near Dilworth.

Thunderstorm Wind in CLAY, MINNESOTA
From 19-JUL-11 04:15:00 to 19-JUL-11 04:15:00 (CST-6)
Location: HAWLEY
Magnitude: 50.00 EG
Reported by: Public

Several large tree branches and limbs were broken down around Hawley.

Flash Flood in OTTER TAIL, MINNESOTA
From 19-JUL-11 05:45:00 to 19-JUL-11 09:00:00 (CST-6)
Location: DUNVILLA
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Several sections of rural road in Dunn Township were flooded.

Flash Flood in BECKER, MINNESOTA
From 19-JUL-11 06:45:00 to 19-JUL-11 09:00:00 (CST-6)
Location: EVERGREEN
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 10.00K
Reported by: Public

Heavy rainfall of two to five inches on top of previously saturated soils produced extensive runoff into the Redeye River drainage. Localized flooding occurred near the river in eastern Evergreen and western Spruce Grove townships.

Flash Flood in OTTER TAIL, MINNESOTA
From 19-JUL-11 07:15:00 to 19-JUL-11 09:00:00 (CST-6)
Location: HILLVIEW
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Heavy rainfall of two to five inches on top of previously saturated soils produced excessive runoff into the Redeye River drainage. Localized flooding occurred near the river through portions of Butler and Paddock townships.

Flash Flood in WADENA, MINNESOTA
From 19-JUL-11 07:45:00 to 19-JUL-11 09:00:00 (CST-6)
Location: SEBEKA
Flood cause: Heavy Rain
Property damage: 3.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Heavy rainfall of two to five inches on top of previously saturated soils produced excessive runoff into the Redeye River drainage. Localized flooding occurred near the river through portions of Redeye and Rockwood townships.

Thunderstorm Wind in BECKER, MINNESOTA
From 19-JUL-11 04:50:00 to 19-JUL-11 04:50:00 (CST-6)
Location: WESTBURY
Magnitude: 55.00 EG
Reported by: Law Enforcement

The strong winds blew down several trees. One tree fell across highway 59.

Flash Flood in CLAY, MINNESOTA
From 19-JUL-11 04:15:00 to 19-JUL-11 08:00:00 (CST-6)
Location: MOORHEAD
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 2.00K
Reported by: Public

Two to three inches of rain in less than an hour caused extensive street flooding. Several roads were impassable.

Flash Flood in CLAY, MINNESOTA
From 19-JUL-11 04:52:00 to 19-JUL-11 08:00:00 (CST-6)
Location: SABIN
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 15.00K
Reported by: COOP Observer

Over 3 inches of rain fell in less than an hour, causing street flooding.

Thunderstorm Wind in OTTER TAIL, MINNESOTA
From 19-JUL-11 05:40:00 to 19-JUL-11 06:00:00 (CST-6)
Location: PERHAM
Magnitude: 60.00 EG
Reported by: Law Enforcement

Many large trees were blown down in Perham.

Thunderstorm Wind in BECKER, MINNESOTA
From 19-JUL-11 05:44:00 to 19-JUL-11 05:44:00 (CST-6)
Location: FRAZEE
Magnitude: 55.00 EG
Reported by: Broadcast Media

A large apple tree was broken in two by the strong winds.

Flash Flood in CLAY, MINNESOTA
From 19-JUL-11 06:00:00 to 19-JUL-11 09:00:00 (CST-6)
Location: SABIN
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Water flowed over several sections of county and township roads in southern and central Harmony township. Numerous farm access roads and fields were flooded.

Thunderstorm Wind in WADENA, MINNESOTA
From 19-JUL-11 06:10:00 to 19-JUL-11 06:20:00 (CST-6)
Location: WADENA
Magnitude: 52.00 EG
Property damage: 100.00K
Crop damage: 50.00K
Reported by: Public

A building under construction at the fairgrounds was blown down.

Flash Flood in BECKER, MINNESOTA
From 19-JUL-11 05:45:00 to 19-JUL-11 09:00:00 (CST-6)
Location: DETROIT LAKES
Flood cause: Heavy Rain
Property damage: 4.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Two to three inches of rain fell in less than an hour, causing street flooding in Detroit Lakes. A few sections of rural road between Detroit Lakes and Frazee were closed due to water running across roadways.