A very unstable airmass was in place over Iowa during the late afternoon and evening of the 22nd.  Surface temperatures warmed into the upper 80s to low 90s over much of the state with dew point temperatures rising into the mid 70s to low 80s.  CAPE values increased to over 6000 J/kg over the southern half of the state with lifted indices around -12 C.  Deep moisture flowed into the state both at low levels as well with the presence of a prominent tropical feed on the water vapor satellite imagery.  Precipitable water values increased to 1.8 to 2.2 inches over southern Iowa as moisture pooled.  Significant shear was present with effective shear of 45 to 60 kts over northern Iowa.  Downdraft CAPE was over 1000 J/kg, while the available CAPE in the -10 to -30 C layer of the atmosphere was in the 800 to 1200 J/kg range.  Hail was somewhat limited however with the freezing level between 14,500 and 15,500 feet.  Temperatures at the 700 mb level rose to +15 C over southwest Iowa by evening.  A strong upper level shortwave lifted northeast out of Colorado during the overnight into the early morning hours of the 22nd into the 23rd.  A cold front approached Iowa from the northwest and moved into the northwestern counties by sunrise on the 23rd.  Thunderstorms were slow to develop initially due to a strong cap in place over the state.  After sunset, explosive development took place over northwest into north central Iowa.  Several tornadoes touched down over northern Iowa.  None of them were on the ground for an extended period of time however.  One touched down in the Sac City area of Sac County, another in Humboldt west of Humboldt.  A third tornado was on the ground for a few minutes in the Eagle Grove area.  A brief touchdown occurred in Franklin County north of Iowa Falls.  A tornado touched down just west of Tripoli.  It obliterated an abandoned barn with a brief touchdown.  The tornado was one of the stronger of the day at EF1 strength.  Funnel clouds were numerous in spite of the darkness due to the vivid lightning and the ability to see them.  There were several hail reports, with some of the hail reaching golf ball in size in Winnebago and Kossuth Counties.  High winds were a more significant problem with the event as it developed in to an upscale MCC.  Numerous reports of downed trees and power lines were received.  A semi was overturned on I-35 at milepost 154 by high wind, with another 10 miles farther north.  Damage to homes and barns was reported in Bremer and Black Hawk Counties as well.  One storm produced a narrow microburst just west of Tripoli with winds estimated at 95 to 100 MPH based on a NWS storm survey.  Three homes were damaged with 2 of them serious.  Some outbuildings were also damaged by this microburst.  The storms also produced very heavy rainfall.  Flash flooding took place in several counties, including Wright, Franklin, and Palo Alto.  Extensive street flooding took place in Clarion in Wright County with power out in most of the city.  In addition, U.S. Highway 69 and Iowa Highway 3 were under water.  U.S. Highway 18 was overtopped by high water in 2 places between Spencer and Emmetsburg in Palo Alto County.  Roads were under water near Sheffield in Franklin County.  Rainfall was heavy with amounts of 4 to 7 inches reported in a band extending from eastern Palo Alto, through Humboldt and Wright Counties, into Franklin County.  Heavy rain flooded roads and resulted in evacuations in the town of Dumont in Butler County.  The rain fell in just a few hours time.  Following the flash flooding, areal flooding continued in parts of the area with highways remaining closed.  Some local flooding was also reported in Warren County, east of the Carlisle area.

Flood in WRIGHT, IOWA
From 23-JUN-10 08:49:00 to 24-JUN-10 13:45:00 (CST-6)
Location: HOLMES
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Highway 3 west of Clarion was closed due to high water over the road from Eagle Creek.  Some blacktop and gravel roads throughout the county were closed by water covering the roads.

Thunderstorm Wind in WRIGHT, IOWA
From 22-JUN-10 21:30:00 to 22-JUN-10 21:30:00 (CST-6)
Location: EAGLE GROVE
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: COOP Observer

Tree damage reported.

Thunderstorm Wind in BREMER, IOWA
From 23-JUN-10 01:16:00 to 23-JUN-10 01:16:00 (CST-6)
Location: TRIPOLI
Magnitude: 83.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Damage was done to a home by microburst straight line winds estimated at 95 MPH.

Tornado in BREMER, IOWA
From 23-JUN-10 01:18:00 to 23-JUN-10 01:19:00 (CST-6)
Location: TRIPOLI
Tornado F-scale: EF1
Property damage: 10.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Tornado was about 35 miles wide with a path of 500 yards.  An abandon farm building was totally destroyed.

Thunderstorm Wind in BREMER, IOWA
From 23-JUN-10 01:27:00 to 23-JUN-10 01:27:00 (CST-6)
Location: SUMNER
Magnitude: 74.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Thunderstorm winds estimated between 80 and 90 MPH by survey team.

Thunderstorm Wind in HUMBOLDT, IOWA
From 22-JUN-10 20:50:00 to 22-JUN-10 20:50:00 (CST-6)
Location: DAKOTA CITY
Magnitude: 57.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Large 100 year old 3 foot diameter tree blown over.  Other smaller trees were also blown over.

Heavy Rain in HUMBOLDT, IOWA
From 22-JUN-10 21:00:00 to 23-JUN-10 04:47:00 (CST-6)
Location: RENWICK MUNI ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall total since last evening was 4.7 inches.

Thunderstorm Wind in CALHOUN, IOWA
From 22-JUN-10 21:10:00 to 22-JUN-10 21:10:00 (CST-6)
Location: POMEROY
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Small branches blown down with power knocked out.

Thunderstorm Wind in CRAWFORD, IOWA
From 22-JUN-10 22:40:00 to 22-JUN-10 22:40:00 (CST-6)
Location: DELOIT
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trees up to 5 inches in diameter blown down.

Thunderstorm Wind in BREMER, IOWA
From 23-JUN-10 01:17:00 to 23-JUN-10 01:17:00 (CST-6)
Location: TRIPOLI
Magnitude: 87.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Straight line microburst destroyed an old barn with winds estimated at 100 MPH.

Thunderstorm Wind in BREMER, IOWA
From 23-JUN-10 01:28:00 to 23-JUN-10 01:28:00 (CST-6)
Location: SUMNER
Magnitude: 65.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Tree down, broken window, and a propane leak.

Flash Flood in PALO ALTO, IOWA
From 23-JUN-10 00:20:00 to 23-JUN-10 06:00:00 (CST-6)
Location: EMMETSBURG
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Broadcast Media

KICD reported that Highway 18 was under water in 2 places between Spencer and Emmetsburg.

Flash Flood in FRANKLIN, IOWA
From 23-JUN-10 01:20:00 to 23-JUN-10 06:00:00 (CST-6)
Location: SHEFFIELD
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reports fast moving water over roads in two places near Sheffield.

Flood in FRANKLIN, IOWA
From 23-JUN-10 08:52:00 to 24-JUN-10 13:45:00 (CST-6)
Location: HAMPTON
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Highway 65 was closed north of Hampton near 180th St. due to water over the road from Otter Creek.

Flood in BUTLER, IOWA
From 23-JUN-10 18:33:00 to 24-JUN-10 13:45:00 (CST-6)
Location: DUMONT
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Emergency Manager

From Highway 3 north to the south half of town is flooding and evacuations are taking place.  West Fork of the Cedar River flooding this area.  Highway 3 is closed east and west of Dumont.

Thunderstorm Wind in FRANKLIN, IOWA
From 22-JUN-10 23:38:00 to 22-JUN-10 23:38:00 (CST-6)
Location: GENEVA
Magnitude: 52.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in WRIGHT, IOWA
From 22-JUN-10 21:30:00 to 22-JUN-10 21:30:00 (CST-6)
Location: EAGLE GROVE
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and power line damage in Eagle Grove.

Thunderstorm Wind in WRIGHT, IOWA
From 22-JUN-10 21:48:00 to 22-JUN-10 21:48:00 (CST-6)
Location: HOLMES
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trees and branches downed by high winds.

Thunderstorm Wind in WRIGHT, IOWA
From 22-JUN-10 21:50:00 to 22-JUN-10 21:50:00 (CST-6)
Location: EAGLE GROVE
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and power lines down.

Thunderstorm Wind in WRIGHT, IOWA
From 22-JUN-10 21:59:00 to 22-JUN-10 21:59:00 (CST-6)
Location: CLARION
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and power lines reported down in Clarion.

Thunderstorm Wind in WRIGHT, IOWA
From 22-JUN-10 22:22:00 to 22-JUN-10 22:22:00 (CST-6)
Location: CLARION
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees and power lines reported down.

Thunderstorm Wind in BREMER, IOWA
From 23-JUN-10 01:16:00 to 23-JUN-10 01:16:00 (CST-6)
Location: BREMER
Magnitude: 83.00 EG
Property damage: 350.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Three houses damaged and 2 barns down.  One house was shifted on its foundation.  Storm survey conclusion was these were straight line winds of about 95 MPH.

Thunderstorm Wind in BLACK HAWK, IOWA
From 23-JUN-10 01:25:00 to 23-JUN-10 01:25:00 (CST-6)
Location: WATERLOO
Magnitude: 69.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Large trees down, power lines down, some damage to home on Gloria Drive.

Thunderstorm Wind in BLACK HAWK, IOWA
From 23-JUN-10 01:30:00 to 23-JUN-10 01:30:00 (CST-6)
Location: WATERLOO
Magnitude: 52.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Tree fell on a house.

Thunderstorm Wind in BLACK HAWK, IOWA
From 23-JUN-10 01:30:00 to 23-JUN-10 01:30:00 (CST-6)
Location: DEWAR
Magnitude: 54.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Estimated wind gusts of 60 to 65 MPH.

Thunderstorm Wind in BLACK HAWK, IOWA
From 23-JUN-10 01:45:00 to 23-JUN-10 01:45:00 (CST-6)
Location: WATERLOO
Magnitude: 57.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Numerous trees blown down.

Tornado in SAC, IOWA
From 22-JUN-10 20:15:00 to 22-JUN-10 20:17:00 (CST-6)
Location: LYTTON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Trained Spotter

Brief tornado occurred between northeast of Sac City.

Tornado in HUMBOLDT, IOWA
From 22-JUN-10 20:12:00 to 22-JUN-10 20:15:00 (CST-6)
Location: UNIQUE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 2.00K
Reported by: Trained Spotter

Brief tornado.

Thunderstorm Wind in FRANKLIN, IOWA
From 22-JUN-10 22:50:00 to 22-JUN-10 22:50:00 (CST-6)
Location: COULTER
Magnitude: 52.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Semi blown over on I-35 at mile post 164.

Thunderstorm Wind in WRIGHT, IOWA
From 22-JUN-10 22:50:00 to 22-JUN-10 22:50:00 (CST-6)
Location: DOWS
Magnitude: 52.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Semi blown over at mile post 154 on I-35.

Thunderstorm Wind in FRANKLIN, IOWA
From 22-JUN-10 22:52:00 to 22-JUN-10 22:52:00 (CST-6)
Location: LATIMER
Magnitude: 67.00 MG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured by a school net site.

Thunderstorm Wind in BUTLER, IOWA
From 23-JUN-10 00:52:00 to 23-JUN-10 00:52:00 (CST-6)
Location: AUSTINVILLE
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trees blown down by high winds.

Tornado in WRIGHT, IOWA
From 22-JUN-10 21:25:00 to 22-JUN-10 21:33:00 (CST-6)
Location: EAGLE GROVE ARPT
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Storm Chaser

Storm chasers reported tornado west of Eagle Grove.

Funnel Cloud in HUMBOLDT, IOWA
From 22-JUN-10 21:10:00 to 22-JUN-10 21:10:00 (CST-6)
Location: THOR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wedge funnel.

Funnel Cloud in HUMBOLDT, IOWA
From 22-JUN-10 21:10:00 to 22-JUN-10 21:10:00 (CST-6)
Location: THOR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large funnel west of Thor visible during lightning strikes.

Funnel Cloud in WRIGHT, IOWA
From 22-JUN-10 21:39:00 to 22-JUN-10 21:39:00 (CST-6)
Location: EAGLE GROVE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Large funnel cloud.

Funnel Cloud in WEBSTER, IOWA
From 22-JUN-10 21:56:00 to 22-JUN-10 21:56:00 (CST-6)
Location: FT DODGE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Just west of Fort Dodge and looking north.  Funnel cloud reported with a wide top wedge.

Funnel Cloud in HARDIN, IOWA
From 22-JUN-10 23:11:00 to 22-JUN-10 23:11:00 (CST-6)
Location: IOWA FALLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in WRIGHT, IOWA
From 22-JUN-10 23:40:00 to 23-JUN-10 04:30:00 (CST-6)
Location: FLORENCE
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 25.00K
Reported by: Emergency Manager

Street flooding in Clarion.  Town still without power.  EM reports nearly every town in Wright County has street flooding.

Flash Flood in FRANKLIN, IOWA
From 23-JUN-10 00:02:00 to 23-JUN-10 06:00:00 (CST-6)
Location: HAMPTON MUNI ARPT
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Highway 65 south of town was under water, with several other roads in town covered with water.

Flash Flood in WRIGHT, IOWA
From 23-JUN-10 00:52:00 to 23-JUN-10 04:30:00 (CST-6)
Location: CLARION
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 10.00K
Reported by: Emergency Manager

Highway 69 was under water 4 miles south of Belmond and Highway 3 was under water 1 mile west of Clarion.

Hail in KOSSUTH, IOWA
From 22-JUN-10 20:49:00 to 22-JUN-10 20:49:00 (CST-6)
Location: GERMAN VLY
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in CALHOUN, IOWA
From 22-JUN-10 20:55:00 to 22-JUN-10 20:55:00 (CST-6)
Location: POMEROY
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in WINNEBAGO, IOWA
From 22-JUN-10 20:57:00 to 22-JUN-10 20:57:00 (CST-6)
Location: BUFFALO CENTER
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 25.00K
Reported by: Fire Department/Rescue

Hail ranging from pea to golf ball size.

Thunderstorm Wind in FRANKLIN, IOWA
From 22-JUN-10 23:40:00 to 22-JUN-10 23:40:00 (CST-6)
Location: GENEVA
Magnitude: 52.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Funnel Cloud in SAC, IOWA
From 22-JUN-10 19:49:00 to 22-JUN-10 19:49:00 (CST-6)
Location: LAKE VIEW
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Funnel Cloud in SAC, IOWA
From 22-JUN-10 20:37:00 to 22-JUN-10 20:37:00 (CST-6)
Location: LYTTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter