Low pressure formed to the west of Iowa and during the morning it was located over central Nebraska with a warm front extending east-southeast across southern Iowa.  The low advanced east during the day as the warm front moved little.  Initially, the airmass was capped by a strong elevated mixed layer.  During the late afternoon and early evening hours, a strong upper level short wave moved into the area.  Temperatures aloft fell rapidly, destabilizing the atmosphere.  Meanwhile, a strong low level jet formed ahead of the approaching low with winds of 40 to 50 kts.  This helped to bring in moisture and increased the precipitable water values to around an inch over much of Iowa.  By late afternoon, most unstable CAPE values were in the 1000 to 2000 J/kg range.  Surface lifted indices were not all that impressive, however the elevated values were in the -3 to -6 C range.  The atmosphere was strongly sheared with 50 to 70 kts of available shear.  The LCL values were quite low as strong heating had not taken place during the day.  LCL heights were between 500 and 1000 meters.  Downdraft CAPE was quite high with values just ahead of the convection between 700 and 1000 J/kg.  The freezing level was quite low, near 11,000 feet, and available CAPE in the -10 to -30 C layer of the atmosphere was between 400 and 500 J/kg.  Thunderstorms fired along and just south of the surface low along a dry line ahead of the associated cold front.  Convection was strong and moved rapidly northeast.  There were two areas of thunderstorms.  A line of strong to severe thunderstorms formed just ahead of the cold front, with more isolated severe convection forming ahead of the main line.  There were numerous reports of tornadoes, mainly with the leading convection.  The three strongest tornadoes took place west to northwest of Creston in Union County, and northwest to north of Winterset in Madison County and southeast of Massena in Cass County.  The tornado in Cass County touched down approximately 1/2 mile east of the intersection of Iowa Hwy 148 and County Hwy G61. It damaged the canopy to an outdoor storage building and tipped over some industrial machinery. It continued northeast and damaged a structure...and caused some minor additional damage to a farmstead north of the intersection of County Hwy G61 and 760th St. Finally, it damaged some outdoor storage bins south of the intersection of County Hwy G53 and 770th Street.  It then lifted.  The same parent storm continued northeast and a small EF0 tornado touched down briefly near Bridgewater in Adair County.  In Madison County, A tornado touched down 10 miles northwest of Winterset. The tornado was characterized by a large circulation up to 0.8 tenths of a mile wide (Iowa Helicopter) and generally of EF1 (90-100 MPH wind) strength.   Eyewitnesses report the tornado was rain wrapped and difficult to distinguish from the rain shield as it approached them from the southwest. The tornado moved across several residences, many of which had broken windows and some roof damage along with significant tree and outbuilding damage. One newly constructed house that was near completion, slid off its foundation with the metal tie down straps either sheered off or pulled out of the concrete foundation. This damage is consistent with winds around 120 MPH which are EF2 strength. The roof structure remained intact and was aided by hurricane clips. Several other residences suffered partial roof removal with no hurricane clips noted. One other location had numerous trees either uprooted or topped and several outbuildings with the roofs blown off.  Objects near the ground did not suffer near as much damage suggesting the peak winds at this location were just off the surface. The tornado lifted around 10 miles north northeast of Winterset or 5 miles south of Van Meter around 1735 CST. The tornado in Union County was not as intense, with damage there relatively minor.  In addition to the line of severe thunderstorms, there was also convection that developed to the north of the low pressure track.  Outside of the tornadic storms, the primary mode of severe weather was hail.  There were reports of hail with most of the storms as they passed, with several reports of hail from quarter up to golf ball in size.  Hail caused damage to roofs and vehicles.  Fortunately, the crops had not been planted so there wasn't any agricultural loss.  A few reports of strong winds were received with wind gusts in the 60 to 65 MPH range.  Some tree and power line damage occurred, but it was not widespread.  Heavy rainfall caused minor flooding in the metropolitan Des Moines area.  A rainfall of 1.73 inches in under 2 hours in West Des Moines resulted in minor urban flooding along EP True Parkway.  Water was standing 1 to 2 feet deep in low drainage areas along the parkway.  There were also numerous reports of urban flooding around the city with water standing in intersections.  As the thunderstorms moved through Butler County, lightning struck a barn near Shell Rock.  The lightning caused damage to the barn and a minor fire.

Tornado in ADAIR, IOWA
From 22-MAR-11 16:42:00 to 22-MAR-11 16:44:00 (CST-6)
Location: BRIDGEWATER
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Tornado near Delta Ave and Highway 92.  Brief touchdown.  This tornado was from the same parent cell the produced an EF1 tornado in Cass County.

Tornado in UNION, IOWA
From 22-MAR-11 17:16:00 to 22-MAR-11 17:21:00 (CST-6)
Location: CROMWELL
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado spotted with debris cloud.

Tornado in MADISON, IOWA
From 22-MAR-11 17:18:00 to 22-MAR-11 17:34:00 (CST-6)
Location: PITZER
Tornado F-scale: EF2
Property damage: 1.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado caused property damage to several farms.  A roof was torn off one of the houses and windows were broken out.

Funnel Cloud in UNION, IOWA
From 22-MAR-11 17:11:00 to 22-MAR-11 17:11:00 (CST-6)
Location: CRESTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large Funnel over Creston.

Funnel Cloud in CASS, IOWA
From 22-MAR-11 17:20:00 to 22-MAR-11 17:20:00 (CST-6)
Location: ANITA MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Funnel Cloud in UNION, IOWA
From 22-MAR-11 17:36:00 to 22-MAR-11 17:36:00 (CST-6)
Location: LORIMOR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Funnel Cloud in WARREN, IOWA
From 22-MAR-11 17:54:00 to 22-MAR-11 17:54:00 (CST-6)
Location: CUMMING
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Funnel Cloud in WARREN, IOWA
From 22-MAR-11 17:57:00 to 22-MAR-11 17:57:00 (CST-6)
Location: NORWALK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Funnel was located along the 2000 block of County Road R45.

Funnel Cloud in WARREN, IOWA
From 22-MAR-11 18:00:00 to 22-MAR-11 18:00:00 (CST-6)
Location: NORWALK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A funnel formed briefly and dissipated with no touchdown.

Funnel Cloud in POLK, IOWA
From 22-MAR-11 18:18:00 to 22-MAR-11 18:18:00 (CST-6)
Location: LOVINGTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter was outdoors watching water ponding on the road and looked up to see a rotating wall cloud.  A funnel formed briefly.

Funnel Cloud in WARREN, IOWA
From 22-MAR-11 18:45:00 to 22-MAR-11 18:45:00 (CST-6)
Location: MARTENSDALE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Rain in POLK, IOWA
From 22-MAR-11 17:55:00 to 22-MAR-11 18:22:00 (CST-6)
Location: ASHAWA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

An inch of rain fell in a short period of time.

Thunderstorm Wind in CASS, IOWA
From 22-MAR-11 16:13:00 to 22-MAR-11 16:13:00 (CST-6)
Location: CUMBERLAND
Magnitude: 52.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Sustained wind speeds were 45 to 50 MPH.

Thunderstorm Wind in CARROLL, IOWA
From 22-MAR-11 16:38:00 to 22-MAR-11 16:38:00 (CST-6)
Location: CARROLL NEU ARPT
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in APPANOOSE, IOWA
From 22-MAR-11 20:45:00 to 22-MAR-11 20:45:00 (CST-6)
Location: MONROVIA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Minor tree damage reported.

Thunderstorm Wind in CARROLL, IOWA
From 22-MAR-11 16:43:00 to 22-MAR-11 16:43:00 (CST-6)
Location: CARROLL NEU ARPT
Magnitude: 56.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: AWOS

Thunderstorm Wind in ADAIR, IOWA
From 22-MAR-11 16:51:00 to 22-MAR-11 16:51:00 (CST-6)
Location: FONTANELLE
Magnitude: 56.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in CALHOUN, IOWA
From 22-MAR-11 18:12:00 to 22-MAR-11 18:12:00 (CST-6)
Location: ROCKWELL CITY
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in CASS, IOWA
From 22-MAR-11 16:05:00 to 22-MAR-11 16:05:00 (CST-6)
Location: GRISWOLD
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CRAWFORD, IOWA
From 22-MAR-11 16:08:00 to 22-MAR-11 16:08:00 (CST-6)
Location: ASPINWALL
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in CASS, IOWA
From 22-MAR-11 16:13:00 to 22-MAR-11 16:13:00 (CST-6)
Location: CUMBERLAND
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CASS, IOWA
From 22-MAR-11 16:23:00 to 22-MAR-11 16:23:00 (CST-6)
Location: CUMBERLAND
Magnitude: 1.50 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter to ping pong ball size hail.

Hail in ADAIR, IOWA
From 22-MAR-11 16:35:00 to 22-MAR-11 16:35:00 (CST-6)
Location: FONTANELLE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAIR, IOWA
From 22-MAR-11 16:44:00 to 22-MAR-11 16:44:00 (CST-6)
Location: FONTANELLE
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ADAIR, IOWA
From 22-MAR-11 16:50:00 to 22-MAR-11 16:50:00 (CST-6)
Location: BRIDGEWATER
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in ADAIR, IOWA
From 22-MAR-11 16:49:00 to 22-MAR-11 16:49:00 (CST-6)
Location: BRIDGEWATER
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Hail in ADAMS, IOWA
From 22-MAR-11 17:03:00 to 22-MAR-11 17:03:00 (CST-6)
Location: PRESCOTT
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Hail in ADAIR, IOWA
From 22-MAR-11 17:13:00 to 22-MAR-11 17:13:00 (CST-6)
Location: ORIENT
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MADISON, IOWA
From 22-MAR-11 17:19:00 to 22-MAR-11 17:19:00 (CST-6)
Location: EARLHAM
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in WRIGHT, IOWA
From 22-MAR-11 17:28:00 to 22-MAR-11 17:28:00 (CST-6)
Location: CORNELIA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Hail in ADAIR, IOWA
From 22-MAR-11 17:30:00 to 22-MAR-11 17:30:00 (CST-6)
Location: GREENFIELD
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Vehicle damage reported along with some roof damage.

Hail in FRANKLIN, IOWA
From 22-MAR-11 17:30:00 to 22-MAR-11 17:30:00 (CST-6)
Location: GENEVA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CASS, IOWA
From 22-MAR-11 17:30:00 to 22-MAR-11 17:30:00 (CST-6)
Location: MASSENA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in POCAHONTAS, IOWA
From 22-MAR-11 17:33:00 to 22-MAR-11 17:33:00 (CST-6)
Location: LAURENS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DALLAS, IOWA
From 22-MAR-11 17:36:00 to 22-MAR-11 17:36:00 (CST-6)
Location: HADDEN HILL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Hail in MADISON, IOWA
From 22-MAR-11 17:43:00 to 22-MAR-11 17:43:00 (CST-6)
Location: WINTERSET
Magnitude: 1.75 
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in POLK, IOWA
From 22-MAR-11 17:44:00 to 22-MAR-11 17:44:00 (CST-6)
Location: CLIVE
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Located at 142nd and Aurora.

Hail in DALLAS, IOWA
From 22-MAR-11 17:44:00 to 22-MAR-11 17:44:00 (CST-6)
Location: HADDEN HILL
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Located at 149th Street and Hickman.

Hail in POLK, IOWA
From 22-MAR-11 17:49:00 to 22-MAR-11 17:49:00 (CST-6)
Location: ASHAWA
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in BUTLER, IOWA
From 22-MAR-11 17:44:00 to 22-MAR-11 17:44:00 (CST-6)
Location: AREDALE
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The sheriff reported nickel to quarter size hail one mile south and one mile west of Aredale.

Hail in POLK, IOWA
From 22-MAR-11 17:59:00 to 22-MAR-11 17:59:00 (CST-6)
Location: ORALABOR
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in POLK, IOWA
From 22-MAR-11 18:01:00 to 22-MAR-11 18:01:00 (CST-6)
Location: URBANDALE
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Located at 67th and Douglas Ave.

Hail in DALLAS, IOWA
From 22-MAR-11 18:07:00 to 22-MAR-11 18:07:00 (CST-6)
Location: DEXTER
Magnitude: 1.00 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail reported covering the ground in Dexter.

Hail in MADISON, IOWA
From 22-MAR-11 18:17:00 to 22-MAR-11 18:17:00 (CST-6)
Location: PITZER
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in TAYLOR, IOWA
From 22-MAR-11 18:10:00 to 22-MAR-11 18:10:00 (CST-6)
Location: LENOX
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MADISON, IOWA
From 22-MAR-11 18:26:00 to 22-MAR-11 18:26:00 (CST-6)
Location: WINTERSET ARPT
Magnitude: 1.75 
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Quarter to golf ball size hail reported.

Hail in DALLAS, IOWA
From 22-MAR-11 18:18:00 to 22-MAR-11 18:18:00 (CST-6)
Location: ADEL
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The location was estimated.

Hail in UNION, IOWA
From 22-MAR-11 18:30:00 to 22-MAR-11 18:30:00 (CST-6)
Location: ARISPE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WARREN, IOWA
From 22-MAR-11 18:41:00 to 22-MAR-11 18:41:00 (CST-6)
Location: CUMMING
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Located on I-35 at mile post 65.

Hail in POLK, IOWA
From 22-MAR-11 18:46:00 to 22-MAR-11 18:46:00 (CST-6)
Location: URBANDALE
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Hail in POLK, IOWA
From 22-MAR-11 18:48:00 to 22-MAR-11 18:48:00 (CST-6)
Location: (DSM)DES MOINES INTL
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in JASPER, IOWA
From 22-MAR-11 18:50:00 to 22-MAR-11 18:50:00 (CST-6)
Location: BAXTER
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in MARSHALL, IOWA
From 22-MAR-11 18:55:00 to 22-MAR-11 18:55:00 (CST-6)
Location: MARSHALLTOWN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in POLK, IOWA
From 22-MAR-11 18:07:00 to 22-MAR-11 18:07:00 (CST-6)
Location: WINDSOR HGTS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in DALLAS, IOWA
From 22-MAR-11 17:41:00 to 22-MAR-11 17:41:00 (CST-6)
Location: HADDEN HILL
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in CASS, IOWA
From 22-MAR-11 16:30:00 to 22-MAR-11 16:34:00 (CST-6)
Location: DEWEY
Tornado F-scale: EF1
Property damage: 150.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

NWS storm survey term related this tornado as an EF1 with a peak wind of 89 MPH.  Track was continuous 2 3/4 mile path.  Most damage was EF0 with one localized EF1 damage area.

Thunderstorm Wind in ADAMS, IOWA
From 22-MAR-11 16:55:00 to 22-MAR-11 16:55:00 (CST-6)
Location: CORNING
Magnitude: 52.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Damage was reported to a machine shed due to thunderstorm winds.

Thunderstorm Wind in CASS, IOWA
From 22-MAR-11 16:22:00 to 22-MAR-11 16:22:00 (CST-6)
Location: CUMBERLAND
Magnitude: 52.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A shed was blown down about 1 mile west of Highway 92 and County road N28.

Heavy Rain in DALLAS, IOWA
From 22-MAR-11 17:00:00 to 22-MAR-11 18:45:00 (CST-6)
Location: HADDEN HILL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of 1.73 inches in an hour and 45 minutes.

Tornado in ADAMS, IOWA
From 22-MAR-11 16:33:00 to 22-MAR-11 16:38:00 (CST-6)
Location: MT ETNA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Weak tornado captured by storm chaser in northern Adams County.

Tornado in MADISON, IOWA
From 22-MAR-11 18:11:00 to 22-MAR-11 18:12:00 (CST-6)
Location: MIDDLE RIVER
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Brief tornado captured by trained spotter.

Lightning in BUTLER, IOWA
From 22-MAR-11 15:12:00 to 22-MAR-11 15:12:00 (CST-6)
Location: SHELL ROCK
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Public

Hail in DALLAS, IOWA
From 22-MAR-11 17:36:00 to 22-MAR-11 17:36:00 (CST-6)
Location: WAUKEE
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in POLK, IOWA
From 22-MAR-11 18:06:00 to 22-MAR-11 18:06:00 (CST-6)
Location: DODGE FLD ARPT
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue