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 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.

Thunderstorm Wind in DODGE, NEBRASKA
From 05-MAY-07 23:30:00 to 05-MAY-07 23:30:00 (CST-6)
Location: HOOPER
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm wind gusts estimated at over 60 mph tore the roof off of a fitness center and caused tree damage near Hooper.

Tornado in KNOX, NEBRASKA
From 05-MAY-07 16:45:00 to 05-MAY-07 16:50:00 (CST-6)
Location: CROFTON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This weak tornado apparently touched down just as one tornado to the southwest was lifting and another stronger one, also to the southwest, was just forming along with this one.  The 3 tornadoes were caught on video by the public.  This tornado did some tree damage and flipped one camper before lifting over Lewis and Clark Lake.

Thunderstorm Wind in BURT, NEBRASKA
From 05-MAY-07 08:35:00 to 05-MAY-07 08:45:00 (CST-6)
Location: TEKAMAH
Magnitude: 65.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS at the Tekamah airport measured a thunderstorm wind gust of 75 mph.  These strong winds downed some large tree limbs southeast of town.

High Wind in PLATTE, NEBRASKA
From 05-MAY-07 22:10:00 to 05-MAY-07 22:20:00 (CST-6)
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Non-thunderstorm wind gusts were measured at 64 mph at the Columbus airport by AWOS.  The winds were possibly a wake low type event and caused some tree and minor structural damage in town.

Flash Flood in SAUNDERS, NEBRASKA
From 05-MAY-07 17:49:00 to 05-MAY-07 19:49:00 (CST-6)
Location: WAHOO
Flood cause: Heavy Rain
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rain caused flash flooding of a ballfield and railroad tracks near town.  Some county bridges also experienced minor washouts.  Rainfall amounts were 2 to 4 inches this day.

Tornado in KNOX, NEBRASKA
From 05-MAY-07 16:17:00 to 05-MAY-07 16:22:00 (CST-6)
Location: WAUSA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This weak tornado remained mostly in open country and only caused some tree damage before lifting.

Tornado in KNOX, NEBRASKA
From 05-MAY-07 16:15:00 to 05-MAY-07 16:20:00 (CST-6)
Location: BLOOMFIELD
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Trees and two or three large power line support structures were damaged in the area and a center pivot was flipped by a tornado that caused damage in about a 200 yard wide path.

Flash Flood in WASHINGTON, NEBRASKA
From 05-MAY-07 09:15:00 to 05-MAY-07 12:15:00 (CST-6)
Location: ARLINGTON
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Rainfall of around 2.5 inches fell in an hour or two across the area causing flooding of several roads around and south of the Arlington area.  In addition...a trap shooting club experienced flooding.  Most of the flooding was along Bell Creek and its tributaries.

Flash Flood in JEFFERSON, NEBRASKA
From 06-MAY-07 00:50:00 to 06-MAY-07 04:50:00 (CST-6)
Location: DILLER
Flood cause: Heavy Rain
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Rainfall of 4 to 6 inches produced flash flooding across parts of Jefferson county during the early morning hours of May 6th, 2007.  One area of flooding was noted along Highway 103 near Diller where water was flowing across the road.  At least 1 county road bridge and a number of culverts were washed out in the area.

Flash Flood in BURT, NEBRASKA
From 05-MAY-07 19:30:00 to 05-MAY-07 20:45:00 (CST-6)
Location: TEKAMAH
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Heavy rain caused flash flooding across Highway 75 near Tekamah briefly closing it.

Hail in PLATTE, NEBRASKA
From 05-MAY-07 10:44:00 to 05-MAY-07 10:44:00 (CST-6)
Location: ROSENBURG
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Reported 4 miles east southeast of St. Edward.

Thunderstorm Wind in JEFFERSON, NEBRASKA
From 06-MAY-07 00:30:00 to 06-MAY-07 00:30:00 (CST-6)
Location: DILLER
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management estimated thunderstorm wind gusts of around 60 mph near Diller.

Hail in PIERCE, NEBRASKA
From 05-MAY-07 15:55:00 to 05-MAY-07 15:55:00 (CST-6)
Location: OSMOND
Magnitude: 3.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Several large hailstones fell and were photographed by the public northwest of Osmond.  One single stone was 3 inches in diameter while a cluster of stones measured 5 inches in diameter.  No damage was reported by the hail.

Thunderstorm Wind in BURT, NEBRASKA
From 06-MAY-07 00:14:00 to 06-MAY-07 00:14:00 (CST-6)
Location: TEKAMAH
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Thunderstorm wind gusts estimated at 60 mph blew out some windows across the eastern section of Burt county according to the Burt County Plaindealer newspaper.  The time was estimated through examination of archived radar data.

Hail in SAUNDERS, NEBRASKA
From 05-MAY-07 18:23:00 to 05-MAY-07 18:23:00 (CST-6)
Location: CEDAR BLUFFS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DOUGLAS, NEBRASKA
From 05-MAY-07 22:28:00 to 05-MAY-07 22:28:00 (CST-6)
Location: OMAHA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Reported near Interstate 80 and 84th Street.

Hail in DODGE, NEBRASKA
From 05-MAY-07 18:30:00 to 05-MAY-07 18:37:00 (CST-6)
Location: FREMONT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail up to 1 inch in diameter was reported in the Fremont area.

Hail in SAUNDERS, NEBRASKA
From 05-MAY-07 18:23:00 to 05-MAY-07 18:23:00 (CST-6)
Location: CEDAR BLUFFS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in BOONE, NEBRASKA
From 05-MAY-07 21:15:00 to 05-MAY-07 21:18:00 (CST-6)
Location: PETERSBURG
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A brief touchdown of a tornado crossed a county road 4 miles west of Loretto or about 7 miles southwest of Petersburg.  The tornado knocked down a line of trees before lifting.

Hail in LANCASTER, NEBRASKA
From 05-MAY-07 16:50:00 to 05-MAY-07 16:50:00 (CST-6)
Location: MALCOLM
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Tornado in KNOX, NEBRASKA
From 05-MAY-07 16:28:00 to 05-MAY-07 16:45:00 (CST-6)
Location: BLOOMFIELD
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The tornado damaged the roof of a hog confinement when it intially touched down.  The tornado continued northward damaging trees, buildings and power lines.  At least one center pivot was damaged along with some home damage.  The worst damage appeared to be 3 miles west of Crofton near where it crossed Highway 12.  This tornado ended just about a mile west where another tornado started producing damage.  In fact, two tornadoes were on the ground at the same time from this supercell, along with a possible landspout or weak tornado to the northeast.

Thunderstorm Wind in KNOX, NEBRASKA
From 05-MAY-07 14:42:00 to 05-MAY-07 14:42:00 (CST-6)
Location: CENTER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds knocked down tree limbs 4 inches in diameter.

Hail in LANCASTER, NEBRASKA
From 05-MAY-07 16:55:00 to 05-MAY-07 16:55:00 (CST-6)
Location: RAYMOND
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in SAUNDERS, NEBRASKA
From 05-MAY-07 18:00:00 to 05-MAY-07 18:00:00 (CST-6)
Location: WESTON
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in OTOE, NEBRASKA
From 05-MAY-07 21:18:00 to 05-MAY-07 21:18:00 (CST-6)
Location: NEBRASKA CITY ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in SARPY, NEBRASKA
From 05-MAY-07 22:25:00 to 05-MAY-07 22:25:00 (CST-6)
Location: PAPILLION
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in OTOE, NEBRASKA
From 05-MAY-07 22:10:00 to 05-MAY-07 22:10:00 (CST-6)
Location: NEBRASKA CITY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in SALINE, NEBRASKA
From 05-MAY-07 16:11:00 to 05-MAY-07 16:11:00 (CST-6)
Location: WILBER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in KNOX, NEBRASKA
From 05-MAY-07 16:10:00 to 05-MAY-07 16:10:00 (CST-6)
Location: WAUSA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in SALINE, NEBRASKA
From 05-MAY-07 16:11:00 to 05-MAY-07 16:11:00 (CST-6)
Location: DORCHESTER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in KNOX, NEBRASKA
From 05-MAY-07 16:18:00 to 05-MAY-07 16:18:00 (CST-6)
Location: CROFTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in LANCASTER, NEBRASKA
From 05-MAY-07 16:45:00 to 05-MAY-07 16:45:00 (CST-6)
Location: DENTON
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in BOONE, NEBRASKA
From 05-MAY-07 14:00:00 to 05-MAY-07 14:00:00 (CST-6)
Location: ALBION
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flash Flood in LANCASTER, NEBRASKA
From 05-MAY-07 17:17:00 to 05-MAY-07 19:30:00 (CST-6)
Location: MALCOLM
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain caused flash flooding from south of Malcolm into the Lincoln area and then south to Firth.  Rainfall of 2 to 4 inches was reported during the afternoon, which was on top of an inch or two that fell that morning.  Lincoln picked up 3.35 inches for the day, with heavier unofficial amounts reported across the city.  The flooding closed several county roads near Malcolm and Wilderness Park and several blocks of Old Cheney Road near the Highway 77 bypass was closed.  The flooding also caused scattered damage to homes and vehicles across the city.  At least 3 cars were stuck in flood waters in the Highlands area, with street flooding as high as car windows.  Flooded vehicles were also reported on O Street in the downtown area and some damage to houses was observed by flooding near the 48th and Saint Paul area.
Flooding was also observed along a 3 block stretch of Nemaha Street in Firth with some basement flooding and basement wall collapses reported.

Hail in KNOX, NEBRASKA
From 05-MAY-07 16:27:00 to 05-MAY-07 16:27:00 (CST-6)
Location: BLOOMFIELD
Magnitude: 4.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Mainly between golfball size and 3.25 inches in diameter, but a few up to softball size.  The hail was very jagged and fell from the supercell that produced several nearby tornadoes.  A Sheriff Department's cruiser was damaged from the hail and there were reports of cattle seriously injured in the area.

Hail in SAUNDERS, NEBRASKA
From 05-MAY-07 18:40:00 to 05-MAY-07 18:40:00 (CST-6)
Location: MALMO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Hail in BURT, NEBRASKA
From 05-MAY-07 19:03:00 to 05-MAY-07 19:03:00 (CST-6)
Location: TEKAMAH
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in BOONE, NEBRASKA
From 05-MAY-07 20:55:00 to 05-MAY-07 20:55:00 (CST-6)
Location: ST EDWARD
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in SALINE, NEBRASKA
From 05-MAY-07 15:49:00 to 05-MAY-07 15:49:00 (CST-6)
Location: TOBIAS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in SALINE, NEBRASKA
From 05-MAY-07 15:58:00 to 05-MAY-07 15:58:00 (CST-6)
Location: WESTERN
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in CEDAR, NEBRASKA
From 05-MAY-07 12:22:00 to 05-MAY-07 12:22:00 (CST-6)
Location: FORDYCE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flash Flood in WASHINGTON, NEBRASKA
From 06-MAY-07 00:52:00 to 06-MAY-07 02:52:00 (CST-6)
Location: ARLINGTON
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A second round of heavy rain moved over Washington county during the evening and overnight hours of May 5th and 6th.  Storm totals were over 4 inches across most of the county.  The heavy rain caused flooding along Bell Creek again near Arlington.  The flooding affected several county roads in the area and also reached the door of several houses.  Otherwise the flooding affected mainly farmland, along with a trap shooting club.

Tornado in KNOX, NEBRASKA
From 05-MAY-07 14:48:00 to 05-MAY-07 15:05:00 (CST-6)
Location: CENTER
Tornado F-scale: EF0
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

This tornado tracked north through a very rural area with most roads in the area minimum maintenance with limited access.  A machine shed was destroyed and a trailer overturned northeast of Center and 6 cattle were killed in the area.  But generally any damage was confined to old deserted farm sites along with trees in the area.

Hail in BOONE, NEBRASKA
From 05-MAY-07 10:55:00 to 05-MAY-07 10:55:00 (CST-6)
Location: ALBION
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in MADISON, NEBRASKA
From 05-MAY-07 10:55:00 to 05-MAY-07 10:55:00 (CST-6)
Location: BATTLE CREEK
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PIERCE, NEBRASKA
From 05-MAY-07 11:42:00 to 05-MAY-07 11:42:00 (CST-6)
Location: PIERCE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in SALINE, NEBRASKA
From 05-MAY-07 16:28:00 to 05-MAY-07 16:28:00 (CST-6)
Location: CRETE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in SALINE, NEBRASKA
From 05-MAY-07 16:07:00 to 05-MAY-07 16:07:00 (CST-6)
Location: WILBER
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in KNOX, NEBRASKA
From 05-MAY-07 12:20:00 to 05-MAY-07 12:20:00 (CST-6)
Location: CROFTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Reported in the Crofton area by the cooperative observer.

Hail in BOONE, NEBRASKA
From 05-MAY-07 13:52:00 to 05-MAY-07 13:52:00 (CST-6)
Location: CEDAR RAPIDS
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in BOONE, NEBRASKA
From 05-MAY-07 13:46:00 to 05-MAY-07 13:46:00 (CST-6)
Location: CEDAR RAPIDS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flash Flood in SALINE, NEBRASKA
From 05-MAY-07 17:05:00 to 05-MAY-07 20:05:00 (CST-6)
Location: DORCHESTER
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Rainfall of 2 to 4 inches in a several hour period produced flash flooding in the streets of Dorchester and Crete.  In the Crete area several cars were flooded up door level and some roads were damaged by flood waters.  Several basements were also flooded.

Tornado in KNOX, NEBRASKA
From 05-MAY-07 16:43:00 to 05-MAY-07 16:51:00 (CST-6)
Location: CROFTON
Tornado F-scale: EF2
Property damage: 1.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

A grain bin was damaged as this tornado initially touched down along with two or three large power line support structures northwest of Crofton.  The tornado tracked toward Lewis and Clark Lake taking the roof off of a house and destroying a garage.  The tornado also caused other roof damage as it continued tracking toward Lewis and Clark Lake.  When it reached the lake it caused significant damage to a recreation area and marina.  The tornado also caused 3 minor injuries when it apparently lifted a large SUV off the ground and carried it a hundred feet or so before setting it down with the windows blown in.  Numerous campers and boats were flipped or missing at the recreation area, along with vehicle damage.  About $1 million in damage was estimated to have occurred at the recreation area. Many trees were also toppled.  This tornado and others in Knox county downed 30 to 40 power poles. A Storage building in the area was also severely damaged.  This tornado started as one tornado to the southwest was lifting and a weaker one to the northeast was forming.  There were several reports by the public of multiple tornadoes in the area, either from the three tornadoes mentioned here, or from multiple vortexes within this tornado.  The tornado crossed Lewis and Clark Lake and did f1 damage in South Dakota.

Tornado in SALINE, NEBRASKA
From 05-MAY-07 15:58:00 to 05-MAY-07 16:28:00 (CST-6)
Location: WESTERN
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

This tornado did intermittent damage from 2 miles south of Western to around 3 miles southeast of Dorchester.  As the tornado initially touched down south of Western, a camper and machine shed were destroyed and a center pivot overturned.  In rural Saline county around 13 miles west of Wilber trees were twisted and uprooted and some building damage was noted and some debris was scattered up to 1/4 mile away from its original location.  Farm outbuildings were severely damaged in the Tabor Hall area, which is 5 miles south of Dorchester, and numerous trees were uprooted or destroyed in the area which destroyed or severely damaged 8 headstones and monuments in a nearby cemetery.  The final damage area was around 3 miles southeast of Dorchester where several pig feeders and livestock huts were destroyed and the roof of a farm outbuilding was removed and a barn destroyed.

Tornado in KNOX, NEBRASKA
From 05-MAY-07 16:24:00 to 05-MAY-07 16:30:00 (CST-6)
Location: BLOOMFIELD
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado initially touched down about 1.5 miles southeast of Bloomfield where it flipped a center pivot.  Tree and outbuilding damage was noted for several miles north of that point, including a few dead livestock.  The damage path became less clear north of town, but some minor debris was noted until about 4 miles north of town.