Low pressure moved northeast out of north central Kansas into central Iowa by mid day on the 12th, then into northern Illinois by evening.  A strong push of very warm and humid air pushed into the state south of the warm front extending east from the low.  Temperatures warmed into the upper 80s to low 90s, with dewpoint temperatures in the low 70s.  The airmass became unstable with CAPE rising to 2500 to 4000 J/kg by mid afternoon.  Precipitable water values rose to around 1.8 inches by late afternoon.  The atmosphere was strongly sheared with 35 to 55 kts of effective shear available.  The lifted index fell to -7 to -9 C.  A very strong cap was in place over much of the state, so in spite of the downdraft CAPE of 900 to 1400 J/kg across the state, it was not realized until very late in the event.  CAPE in the -10 to -30 C layer of the atmosphere was in the 600 to 800 J/kg range.  The freezing level was quite high, at 15,200 feet, limiting the hail potential through much of the event.  During the evening, as the surface low pressure moved to the east of the area.  Temperatures aloft fell rapidly and the character of the storms changed from supercellular to short line segments.  They began producing hail with the largest in Bremer County east of Readlyn with golf ball to baseball size hail.  The LCL was low, around 750 meters, making for a favorable environment for tornadic development.  Seven tornadoes occurred during the afternoon hours in Wright and Franklin counties with the strongest tornado rating of EF3. Flooding occurred in north central Iowa in parts of Cerro Gordo and Worth County.  Rainfall of 2 to 3 inches in under an hour occurred, resulting in flash flooding initially, then general flooding overnight.  Numerous roads were flooded and closed.  Rescue operations took place in Worth County as motorists were stranded by the rising water.  The motorist hydroplaned off of a highway into a ditch full of water.  After the rain ended, flooding continued through the night as standing water took several hours to recede.

Funnel Cloud in FRANKLIN, IOWA
From 12-JUN-13 14:29:00 to 12-JUN-13 14:29:00 (CST-6)
Location: ALEXANDER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported funnel cloud reached nearly half way to the ground before dissipating.

Heavy Rain in WORTH, IOWA
From 12-JUN-13 20:25:00 to 12-JUN-13 20:25:00 (CST-6)
Location: GRAFTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of 2.84 inches in the past few hours in Grafton.

Heavy Rain in BLACK HAWK, IOWA
From 12-JUN-13 20:00:00 to 12-JUN-13 21:20:00 (CST-6)
Location: CEDAR FALLS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Reported rainfall of 1.74 inches since 2000 CST in Cedar Falls.

Flash Flood in CERRO GORDO, IOWA
From 12-JUN-13 20:27:00 to 13-JUN-13 01:30:00 (CST-6)
Location: MASON CITY
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Multiple fields under water across northeast Cerro Gordo County. Many gravel roads have water over them. Three campgrounds were evacuated: Camp at the Woods, Wilkinson County Park and Shell Rock Preserve due to water impacting the entrances/exits.

Flood in WORTH, IOWA
From 13-JUN-13 06:00:00 to 13-JUN-13 07:30:00 (CST-6)
Location: BRISTOL
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Portions of Apple Ave washed out or with water over the road at 470th, 490th, and between Apple and HWY 69.

Flood in WORTH, IOWA
From 13-JUN-13 06:00:00 to 13-JUN-13 07:30:00 (CST-6)
Location: KENSETT
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Sections of U.S. Highway 65 down to one lane due to flooding.

Thunderstorm Wind in CERRO GORDO, IOWA
From 12-JUN-13 18:50:00 to 12-JUN-13 18:50:00 (CST-6)
Location: PLYMOUTH
Magnitude: 52.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several 4 inch diameter tree limbs blown down.

Hail in BREMER, IOWA
From 12-JUN-13 16:30:00 to 12-JUN-13 16:30:00 (CST-6)
Location: JANESVILLE
Magnitude: 1.00 
Property damage: 1.00K
Crop damage: 5.00K
Reported by: Broadcast Media

Reported by KWWL TV channel 7 in Waterloo.

Hail in BREMER, IOWA
From 12-JUN-13 19:11:00 to 12-JUN-13 19:11:00 (CST-6)
Location: READLYN
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: Trained Spotter

Hail in BREMER, IOWA
From 12-JUN-13 18:50:00 to 12-JUN-13 18:55:00 (CST-6)
Location: BREMER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 18:50:00 to 12-JUN-13 19:00:00 (CST-6)
Location: BREMER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:09:00 to 12-JUN-13 19:09:00 (CST-6)
Location: TRIPOLI
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:06:00 to 12-JUN-13 19:06:00 (CST-6)
Location: KNITTEL
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 18:50:00 to 12-JUN-13 18:50:00 (CST-6)
Location: BREMER
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 18:52:00 to 12-JUN-13 18:52:00 (CST-6)
Location: TRIPOLI
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:02:00 to 12-JUN-13 19:02:00 (CST-6)
Location: ARTESIAN
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:06:00 to 12-JUN-13 19:06:00 (CST-6)
Location: ARTESIAN
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:01:00 to 12-JUN-13 19:01:00 (CST-6)
Location: ARTESIAN
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:08:00 to 12-JUN-13 19:08:00 (CST-6)
Location: TRIPOLI
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:11:00 to 12-JUN-13 19:11:00 (CST-6)
Location: KNITTEL
Magnitude: 2.00 
Property damage: 15.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:10:00 to 12-JUN-13 19:10:00 (CST-6)
Location: TRIPOLI
Magnitude: 1.25 
Property damage: 3.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:15:00 to 12-JUN-13 19:15:00 (CST-6)
Location: BUCK CREEK
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:05:00 to 12-JUN-13 19:05:00 (CST-6)
Location: KNITTEL
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:10:00 to 12-JUN-13 19:10:00 (CST-6)
Location: KNITTEL
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:13:00 to 12-JUN-13 19:13:00 (CST-6)
Location: BUCK CREEK
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:14:00 to 12-JUN-13 19:14:00 (CST-6)
Location: READLYN
Magnitude: 2.00 
Property damage: 15.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:14:00 to 12-JUN-13 19:14:00 (CST-6)
Location: READLYN
Magnitude: 2.75 
Property damage: 25.00K
Crop damage: 15.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:10:00 to 12-JUN-13 19:20:00 (CST-6)
Location: READLYN
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:08:00 to 12-JUN-13 19:08:00 (CST-6)
Location: READLYN
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 15.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:16:00 to 12-JUN-13 19:16:00 (CST-6)
Location: READLYN
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 15.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:13:00 to 12-JUN-13 19:13:00 (CST-6)
Location: BUCK CREEK
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 15.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:12:00 to 12-JUN-13 19:12:00 (CST-6)
Location: BUCK CREEK
Magnitude: 1.75 
Property damage: 10.00K
Crop damage: 15.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:20:00 to 12-JUN-13 19:20:00 (CST-6)
Location: BUCK CREEK
Magnitude: 1.00 
Property damage: 2.00K
Crop damage: 10.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:07:00 to 12-JUN-13 19:07:00 (CST-6)
Location: BREMER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 18:52:00 to 12-JUN-13 18:52:00 (CST-6)
Location: FREDERIKA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project

Hail in BREMER, IOWA
From 12-JUN-13 19:13:00 to 12-JUN-13 19:13:00 (CST-6)
Location: TRIPOLI
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project

Tornado in WRIGHT, IOWA
From 12-JUN-13 15:08:00 to 12-JUN-13 15:27:00 (CST-6)
Location: OLAF
Tornado F-scale: EF3
Property damage: 500.00K
Crop damage: 5.00K
Reported by: NWS Storm Survey

EF3 tornado with a winds of 155 MPH.  Damaged farmsteads and businesses with most damage on the north edge of Belmond near the intersection of Highway 65 and County Road C20.

Tornado in WRIGHT, IOWA
From 12-JUN-13 15:19:00 to 12-JUN-13 15:32:00 (CST-6)
Location: BELMOND
Tornado F-scale: EF1
Property damage: 20.00K
Crop damage: 5.00K
Reported by: NWS Storm Survey

Tornado formed on the east edge of town near the elementary school destroying an automated weather station.  The storm then moved eastward before turning southeast over rural areas of Wright county.

Tornado in FRANKLIN, IOWA
From 12-JUN-13 15:32:00 to 12-JUN-13 15:44:00 (CST-6)
Location: ALEXANDER
Tornado F-scale: EF2
Property damage: 300.00K
Crop damage: 10.00K
Reported by: NWS Storm Survey

The tornado heavily damaged several farms while the rear flank downdraft winds produced an even wider damage path to the south of the tornado.

Tornado in FRANKLIN, IOWA
From 12-JUN-13 15:46:00 to 12-JUN-13 15:55:00 (CST-6)
Location: LATIMER
Tornado F-scale: EF1
Property damage: 50.00K
Crop damage: 1.00K
Reported by: NWS Storm Survey

The tornado damaged a barn roof and about a dozen trees on two farmsteads.

Tornado in FRANKLIN, IOWA
From 12-JUN-13 15:56:00 to 12-JUN-13 15:59:00 (CST-6)
Location: BEEDS LAKE ARPT
Tornado F-scale: EF0
Property damage: 10.00K
Crop damage: 1.00K
Reported by: NWS Storm Survey

The last tornado in the series.  This tornado lightly damaged a barn roof and a few trees northwest of Hampton.

Hail in BREMER, IOWA
From 12-JUN-13 18:35:00 to 12-JUN-13 18:35:00 (CST-6)
Location: PLAINFIELD
Magnitude: 1.50 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Hail in BREMER, IOWA
From 12-JUN-13 18:35:00 to 12-JUN-13 18:35:00 (CST-6)
Location: PLAINFIELD
Magnitude: 1.75 
Property damage: 5.00K
Crop damage: 10.00K
Reported by: Public

Flash Flood in CERRO GORDO, IOWA
From 12-JUN-13 19:13:00 to 12-JUN-13 19:13:00 (CST-6)
Location: PLYMOUTH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Storm Chaser

Water was reported in low lying fields and creeks were out of their banks. Water over 330th St. north of Rock Falls.

Flash Flood in WORTH, IOWA
From 12-JUN-13 20:33:00 to 13-JUN-13 01:30:00 (CST-6)
Location: MANLY
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Many roads impassable and washed out across the county especially in areas around Manly and areas south of HWY 9 and 410th st south to the county line.

Thunderstorm Wind in WORTH, IOWA
From 12-JUN-13 18:45:00 to 12-JUN-13 18:45:00 (CST-6)
Location: KENSETT
Magnitude: 60.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Fifteen power poles down at 400th and Orchid. Several trees and power poles down across the county.

Tornado in FRANKLIN, IOWA
From 12-JUN-13 15:53:00 to 12-JUN-13 15:56:00 (CST-6)
Location: BEEDS LAKE ARPT
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 5.00K
Reported by: Public

This was the 5th tornado in a series of 6 from a thunderstorm on June 12th.  This was a well documented tornado on video and developed while the 4th tornado in the series was ongoing.  This tornado drifted southeast and stayed over open farmland in Franklin county.

Tornado in WRIGHT, IOWA
From 12-JUN-13 15:21:00 to 12-JUN-13 15:24:00 (CST-6)
Location: OLAF
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

This tornado occurred as the Belmond EF3 tornado was passing just northeast of town.  The tornado tracked south-southeast across open farmland before dissipating. The track was very evident in satellite imagery taken shortly after the storm occurred.  The location of the tornado in the storm, track direction and streaks in the satellite imagery all suggest that this tornado rotated anti-cyclonically.

Funnel Cloud in CERRO GORDO, IOWA
From 12-JUN-13 16:40:00 to 12-JUN-13 16:40:00 (CST-6)
Location: THORNTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Funnel Cloud in FRANKLIN, IOWA
From 12-JUN-13 16:54:00 to 12-JUN-13 16:54:00 (CST-6)
Location: SHEFFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A weak funnel cloud was reported on the east edge of the Sheffield city limits.

Funnel Cloud in FRANKLIN, IOWA
From 12-JUN-13 17:24:00 to 12-JUN-13 17:24:00 (CST-6)
Location: HANSELL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Rain in WORTH, IOWA
From 12-JUN-13 17:00:00 to 12-JUN-13 17:30:00 (CST-6)
Location: NORTHWOOD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A Co-op observer measured 1.97 inches of rain between 1700 and 1730 CST.

Hail in BREMER, IOWA
From 12-JUN-13 19:20:00 to 12-JUN-13 19:20:00 (CST-6)
Location: TRIPOLI
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 5.00K
Reported by: SHAVE Project