A warm front that was along the Kansas and Nebraska border early Saturday morning May 5th, lifted north during the day bringing widespread heavy rain and severe weather, including tornadoes, to eastern Nebraska and southwest Iowa.  The warm front was part of a large upper level system that brought several days of severe weather and flooding to the region.
Heavy rain and flooding was reported with some of the activity Saturday morning, along with isolated severe thunderstorm reports.  However, during the afternoon the severe weather became more widespread over northeast Nebraska where supercells spawned several tornadoes.  At this time, thunderstorms, some severe with heavy rain, produced flash flooding over parts of southeast Nebraska.  By evening much of the severe weather, including supercell producing tornadoes, shifted into southwest Iowa, although isolated severe thunderstorms persisted over parts of eastern Nebraska until after midnight CDT.

Tornado in MILLS, IOWA
From 05-MAY-07 19:09:00 to 05-MAY-07 19:11:00 (CST-6)
Location: STRAHAN
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado continued from Fremont county where it blew down grain bins, sheds and barns and destroyed trees.  The track in Mills county was about 1/2 mile long and most of the damage was done in Fremont county.  The tornado crossed into Mills county near Highway 59 northeast of Imogene.

Hail in POTTAWATTAMIE, IOWA
From 05-MAY-07 21:22:00 to 05-MAY-07 21:22:00 (CST-6)
Location: COUNCIL BLUFFS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Rain in HARRISON, IOWA
From 05-MAY-07 09:40:00 to 05-MAY-07 10:03:00 (CST-6)
Location: MONDAMIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The public reported some minor flooding due to 1.7 inches of rain that fell in 20 minutes.

Tornado in POTTAWATTAMIE, IOWA
From 05-MAY-07 19:46:00 to 05-MAY-07 19:52:00 (CST-6)
Location: MACEDONIA
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado crossed into Pottawattamie county from Montgomery county about 4 miles southeast of Macedonia.  The total path length was around 11.5 miles.  Although over half of it was in Pottawattamie county, most of the damage was done in Montgomery county where a roof was torn off of a house, barns were destroyed and cars were tossed into a field.

Flash Flood in MILLS, IOWA
From 06-MAY-07 02:00:00 to 06-MAY-07 04:00:00 (CST-6)
Location: GLENWOOD
Flood cause: Heavy Rain
Property damage: 2.50M
Crop damage: 0.00K
Reported by: Newspaper

Rainfall of 3 to 4 inches fell across the Glenwood area which caused Keg Creek to flash flood across parts of town.  The flooding prompted emergency management crews to go door-to-door to alert residents about the impending flood, although no mandatory evacuations were required.  Flooding along Keg Creek, other small creeks across the county and the West Nishnabotna River caused over 2 million dollars worth of damage to roads and bridges and for debris removal.

Tornado in MILLS, IOWA
From 05-MAY-07 18:09:00 to 05-MAY-07 18:16:00 (CST-6)
Location: GLENWOOD
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A tornado tracked south of Glenwood for about 4 miles according to storm spotters that followed it.  The tornado remained in open fields, and did little if any apparent damage.

Tornado in MONTGOMERY, IOWA
From 05-MAY-07 19:40:00 to 05-MAY-07 19:46:00 (CST-6)
Location: RED OAK
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

This tornado tore the roof off of a house, destroyed a barn, downed trees and power poles and tossed cars into a field.  Most of the damage was in Montgomery county, east of Henderson (which is in Mills county).  The tornado crossed into Pottawattamie county about 4 miles southeast of Macedonia.  The total path length was around 11.5 miles.

Tornado in POTTAWATTAMIE, IOWA
From 05-MAY-07 20:00:00 to 05-MAY-07 20:06:00 (CST-6)
Location: OAKLAND
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado damaged trees and destroyed barns and sheds in its path.  Some power poles were also downed.

Hail in PAGE, IOWA
From 06-MAY-07 00:58:00 to 06-MAY-07 00:58:00 (CST-6)
Location: SHAMBAUGH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Heavy Rain in MILLS, IOWA
From 05-MAY-07 18:30:00 to 06-MAY-07 00:52:00 (CST-6)
Location: GLENWOOD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The cooperative observer in Glenwood measured 3.7 inches of rain from 730 pm until a little after midnight cdt.

Heavy Rain in SHELBY, IOWA
From 05-MAY-07 05:27:00 to 06-MAY-07 05:27:00 (CST-6)
Location: IRWIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The cooperative observer near Irwin reported a 24 hour rainfall amount of 4.55 inches.

Tornado in FREMONT, IOWA
From 05-MAY-07 18:50:00 to 05-MAY-07 19:09:00 (CST-6)
Location: FARRAGUT
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The tornado damaged or destroyed trees in its nearly 12 mile path along with some grain bins, sheds and barns.  The tornado crossed into extreme southeast Mills county near Highway 59 northeast of Imogene before lifting about a half mile into that county.  Most of the damage was done in Fremont county.

Flash Flood in HARRISON, IOWA
From 05-MAY-07 22:28:00 to 06-MAY-07 04:30:00 (CST-6)
Location: MISSOURI VLY
Flood cause: Dam / Levee Break
Property damage: 15.00M
Crop damage: 0.00K
Reported by: Law Enforcement

Rainfall of 5 inches fell across the Missouri Valley area Saturday May 5th prompting the levee along Willow Creek to eventually fail causing substantial flash flooding in and around the Missouri Valley area.
Initally flash flooding was observed due to the heavy rain Saturday evening the 5th near Highway 30 and county road 66.  The levee failure caused more substantial flash flooding early Sunday the 6th with many residents barely able to escape the rising flood waters. The area most affected was the southwest part of town, which sat below the bluffs where most of the town is located.  At least 77 homes and 6 businesses were flooded and declared an almost complete loss.  Many vehicles were also flooded or severely damaged. Interstate 29 was closed for a while near town, along with Highway 30 and other local roads. The high water continued in the area well into the following week. It was estimated that road repair alone would cost several million dollars.  Although homes in the higher sections of town escaped flood waters from the levee break, many sustained damage due to flooded basements, mudslides or basement walls caving in.  The flooding prompted schools to be closed on Monday May 7th.

Thunderstorm Wind in MONONA, IOWA
From 05-MAY-07 19:45:00 to 05-MAY-07 19:45:00 (CST-6)
Location: ONAWA
Magnitude: 60.00 EG
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm wind gusts estimated at over 60 mph caused roof damage to a business by displacing large air-conditioning units.  The winds also blew the roof canopy off of a truck stop into cars in a parking lot.

Hail in FREMONT, IOWA
From 05-MAY-07 17:45:00 to 05-MAY-07 17:45:00 (CST-6)
Location: THURMAN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Flash Flood in MONONA, IOWA
From 05-MAY-07 20:15:00 to 05-MAY-07 23:15:00 (CST-6)
Location: ONAWA
Flood cause: Heavy Rain
Property damage: 1.44M
Crop damage: 0.00K
Reported by: Law Enforcement

Rainfall of 3 to 4 inches produce flash flooding of streets in Onawa.  Other creeks across the county flooded county roads causing road, bridge and levee damage.

Hail in MONONA, IOWA
From 05-MAY-07 09:57:00 to 05-MAY-07 09:57:00 (CST-6)
Location: RODNEY
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in HARRISON, IOWA
From 05-MAY-07 19:00:00 to 05-MAY-07 19:00:00 (CST-6)
Location: RIVER SIOUX
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in MONONA, IOWA
From 05-MAY-07 19:20:00 to 05-MAY-07 19:20:00 (CST-6)
Location: BLENCOE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in POTTAWATTAMIE, IOWA
From 05-MAY-07 20:09:00 to 05-MAY-07 20:09:00 (CST-6)
Location: OAKLAND
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in MONTGOMERY, IOWA
From 06-MAY-07 01:21:00 to 06-MAY-07 01:31:00 (CST-6)
Location: STANTON
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A tornado that was on the ground for nearly 8 miles caused damage to farm outbuildings and trees along its path.