A strong warm advection pattern set up over Iowa during the evening of the 21st into the morning hours of the 22nd.  Strong moisture transport pooled moisture over the state with precipitable water values increasing to 2 to 2.3 inches over the north half of the state.  An MCC developed over southeast South Dakota and far northeast Nebraska during the evening.  The MCS was fed by 2000 to 3000 J/kg of CAPE with a relatively unstable atmosphere.  Lifted indices were around -4 C.  The shear environment was relatively favorable with 40 to 50 kts of effective shear over the area.  Thunderstorms trained over northern Iowa and produced heavy rainfall amounts.  Rainfall amounts of 3 to 5 inches were common from Hardin County, west through Sac County and into Pocahontas County.  Five inches of rain fell in a 2-3 hour period just west of Fort Dodge.  This resulted in flash flooding in the area.  Flowing water 2 to 3 feet deep was reported in the city of Fort Dodge.  Flash flooding also occurred in Sac and Calhoun Counties.  Numerous roads were flooded with numerous basements flooded in Manson.  During the early stage of the MCC development, severe weather occurred in Pocahontas County.  A strong shear environment was observed at the time over Pocahontas County.  In the city of Pocahontas, a Coop building and implement machine shed had significant damage along Highway 3 and Main Street.  Several large tree branches were downed with whole trees blown down on the northeast side of town.  Some of the trees were 3 feet in diameter.  Damage was also reported at the country club in Pocahontas.  An EF1 tornado moved through the southeast part of town as well with this storm.  The tornado touched down 1 to 2 miles south of Pocahontas near Highway 4.  It traveled 2.6 miles on the ground, then lifted just northeast of the golf course and prior to reaching the airport.  The tornado was described as diffuse in nature.  Damage included a Coop suffering partial structural collapse and the roof and ceiling lifted off the structure.  At the Sale Barn, machinery and carts were carried aloft both west and northwest of the location due to the circulation of the tornado.  The walls of the barn were also damaged by the tornado.  Three to four foot diameter trees were also uprooted and down in the Pocahontas Cemetery.  The tornado lifted off the ground at approximately 0141 CST.  The wind speed was estimated to be 100 MPH.

Flash Flood in WEBSTER, IOWA
From 22-JUL-10 04:00:00 to 22-JUL-10 08:00:00 (CST-6)
Location: FT DODGE
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Flooding was reported along 6th Ave North. Along 2nd Ave North there was flooding with water up to the windows of cars and 5th Ave South had to be closed.

Flash Flood in WEBSTER, IOWA
From 22-JUL-10 03:45:00 to 22-JUL-10 08:00:00 (CST-6)
Location: FT DODGE
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Two to 3 feet of water was reported flowing in numerous intersections.

Flash Flood in WEBSTER, IOWA
From 22-JUL-10 07:00:00 to 22-JUL-10 08:00:00 (CST-6)
Location: FT DODGE
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The intersection of Highway 169 and Business 20 was flooded.

Flash Flood in CALHOUN, IOWA
From 22-JUL-10 07:00:00 to 22-JUL-10 08:00:00 (CST-6)
Location: ROCKWELL CITY
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Highway 4 south of Rockwell City is closed due to flooding.  Humpty Dumpty Park in Rockwell City is flooded.  Water reported in numerous basements in Manson.

Heavy Rain in HAMILTON, IOWA
From 22-JUL-10 00:00:00 to 22-JUL-10 06:49:00 (CST-6)
Location: WEBSTER CITY ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Overnight rainfall total was 4.80 inches.

Thunderstorm Wind in POCAHONTAS, IOWA
From 22-JUL-10 01:33:00 to 22-JUL-10 01:33:00 (CST-6)
Location: POCAHONTAS
Magnitude: 65.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Coop building and implement machine shed had significant damage near Highway 3 and Main Street.  Several large tree branches were down with whole trees downed on the northeast side of town.  Tree damage was also reported at the country club in town.

Heavy Rain in WEBSTER, IOWA
From 21-JUL-10 23:00:00 to 22-JUL-10 07:00:00 (CST-6)
Location: GOWRIE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of 3.50 inches recorded in the past 8 hours.

Tornado in POCAHONTAS, IOWA
From 22-JUL-10 01:38:00 to 22-JUL-10 01:41:00 (CST-6)
Location: WESTVIEW
Tornado F-scale: EF1
Property damage: 1.00M
Crop damage: 10.00K
Reported by: NWS Storm Survey

Tornado touched down 1 mile south of Pocahontas near Highway 4.  It traveled 2.6 miles on the ground and lilfted northeast of the golf course and prior to the airport.  Peak wind was estimated to be 100 MPH.

Heavy Rain in WEBSTER, IOWA
From 22-JUL-10 01:14:00 to 22-JUL-10 03:44:00 (CST-6)
Location: FT DODGE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Total rainfall within the past 2-3 hours was 5 inches.  Three to 6 inches of ponding water was reported in the neighbors backyard.

Flash Flood in SAC, IOWA
From 22-JUL-10 07:00:00 to 22-JUL-10 08:00:00 (CST-6)
Location: SCHALLER
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Numerous roads were closed, including Hope Ave between 190th and 200th St, 170th between Ira and Jackson, Lee Ave was down to one lane between 390th and 400th.

Heavy Rain in CALHOUN, IOWA
From 22-JUL-10 00:00:00 to 22-JUL-10 07:26:00 (CST-6)
Location: MANSON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rainfall overnight totaled 4.20 inches.