A strong upper level trough and associated cold front pushed across the region during the afternoon and evening of March 22.  The upper level system caused low pressure to deepen over eastern Nebraska/northeast Kansas with a warm front extending northeast from the low into east central Nebraska and southwest Iowa.  By mid afternoon, ahead of the cold front and south of the warm front, temperatures climbed into the upper 70s to lower 80s and dew point temperatures reached the upper 50s.  The instability and shear near the low and warm front created a favorable environment for supercell development, a few of which produced damaging hail and at least 3 tornadoes in the area.

Tornado in HARRISON, IOWA
From 22-MAR-11 16:00:00 to 22-MAR-11 16:19:00 (CST-6)
Location: EUCLID
Tornado F-scale: EF1
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A NWS storm survey assessment team confirmed a tornado tracked around 12 miles starting from a few miles east of Missouri Valley to around 5 miles southeast of Woodbine, Iowa.  The tornado destroyed at least 1 mobile home, which caused minor injuries to 2 occupants, and caused outbuilding, home and vehicle damage along it path which reached around 100 yards wide at its widest.  The strongest damage was estimated at EF1.

Thunderstorm Wind in MILLS, IOWA
From 22-MAR-11 15:40:00 to 22-MAR-11 15:40:00 (CST-6)
Location: EMERSON
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm wind gusts were estimated at 60 mph by a NWS employee along with nickel-size hail.

Hail in MILLS, IOWA
From 22-MAR-11 15:40:00 to 22-MAR-11 15:40:00 (CST-6)
Location: EMERSON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Nickel-size hail was accompanied by thunderstorm wind gusts estimated at 60 mph near Emerson.

Hail in HARRISON, IOWA
From 22-MAR-11 16:05:00 to 22-MAR-11 16:10:00 (CST-6)
Location: LOGAN
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Newspaper

Hail up to golf ball-size fell in the Logan area associated with the same supercell thunderstorm that produced a tornado near the area.  The hail caused significant vehicle and roof and siding damage in and around town.

Hail in HARRISON, IOWA
From 22-MAR-11 16:03:00 to 22-MAR-11 16:03:00 (CST-6)
Location: MISSOURI VLY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

From the supercell thundestorm that produced a tornado near this area.

Tornado in SHELBY, IOWA
From 22-MAR-11 16:47:00 to 22-MAR-11 16:50:00 (CST-6)
Location: DEFIANCE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser caught a rope tornado on video southwest of Defiance.  The narrow and weak tornado apparently caused no damage as it remained in an open field and was from the same supercell that spawned a larger tornado to the southwest in Harrison county a little earlier.

Hail in MONTGOMERY, IOWA
From 22-MAR-11 15:56:00 to 22-MAR-11 16:04:00 (CST-6)
Location: RED OAK
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail up to golf ball-size was reported in and near Red Oak.

Hail in HARRISON, IOWA
From 22-MAR-11 16:04:00 to 22-MAR-11 16:04:00 (CST-6)
Location: EUCLID
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

From the same supercell that produced a tornado near the area.

Hail in HARRISON, IOWA
From 22-MAR-11 16:20:00 to 22-MAR-11 16:20:00 (CST-6)
Location: WOODBINE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter