The continued series of thunderstorms moved across Iowa during the afternoon of the 26th and through the overnight hours of the 26th into the 27th.  A stationary front remained in place from central Nebraska into northern Missouri.  The front aloft remained over Iowa, setting the stage for repeated thunderstorm development.  The parameters changed little from the previous event.  A weakly sheared atmosphere was in place with 25 to 30 kts of shear available.  CAPE values were slightly higher, in the 1000 to 2000 J/kg range.  Downdraft CAPE ranged from under 400 J/kg over the east part of the CWA to 800 J/kg over the west.  A substantial inversion was in place over most of the Des Moines CWA.  CAPE in the -10 to -30 C layer of the atmosphere was relatively low, only 200 to 400 J/kg.  Precipitable water values were in the 1.3 to 1.6 inch range, or over 2 standard deviations above normal.  Thunderstorms from the previous night weakened, only to be replaced by a new round of thunderstorms that developed over northwest Iowa by mid day on the 26th.  These storms moved southeast across the state, producing heavy rain across many of the areas that received heavy rainfall the night before.  Highway closings were too numerous to mention with many small creeks overflowing their banks and causing flash flooding.  There were several reports of road washouts and bridges being washed out.  A man driving a SUV was swept away by swift flood waters Monday morning on Westbrook Street in Butler County west of Parkersburg.  Severe weather was limited.  The storms produced half dollar size hail in Taylor County.  Hail also fell in Humboldt and Polk Counties.  A funnel cloud was reported in Taylor County as well.  One brief tornado touchdown was reported southwest Diagonal in Ringgold County.  On the morning of the 27th, as the second MCS decayed, high winds occurred over a small part of north central into central Iowa as a wake low formed.  Winds gusted to 58 MPH in Polk County at Ankeny.  An RWIS site in Marshall County at Marshalltown recorded a 60 MPH wind gust.  Wind damage occurred in Boone County and Hardin Counties.  Sustained winds of 40 to 45 MPH were reported in Jasper and Story Counties.  Scattered reports of outbuilding and tree damage were received.

Hail in CRAWFORD, IOWA
From 26-MAY-13 15:33:00 to 26-MAY-13 15:33:00 (CST-6)
Location: BOYER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Funnel Cloud in TAYLOR, IOWA
From 26-MAY-13 19:07:00 to 26-MAY-13 19:07:00 (CST-6)
Location: BLOCKTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in GUTHRIE, IOWA
From 27-MAY-13 03:22:00 to 27-MAY-13 08:00:00 (CST-6)
Location: FANSLERS
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Water over the spillway and road in Springbrook State Park.  DNR is evacuating the park.

Flash Flood in GUTHRIE, IOWA
From 27-MAY-13 03:30:00 to 27-MAY-13 08:00:00 (CST-6)
Location: BAGLEY
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Water flowing over Quail Road.

Flood in GUTHRIE, IOWA
From 27-MAY-13 08:23:00 to 27-MAY-13 12:45:00 (CST-6)
Location: BAGLEY
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flood waters moving over highway 141 from water flowing out of fields.

High Wind in POLK, IOWA
From 27-MAY-13 08:00:00 to 27-MAY-13 08:30:00 (CST-6)
Magnitude: 50.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: AWOS

Measured at the Ankeny Airport.

High Wind in STORY, IOWA
From 27-MAY-13 07:30:00 to 27-MAY-13 08:30:00 (CST-6)
Magnitude: 35.00 ES
Property damage: 5.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in MARSHALL, IOWA
From 27-MAY-13 07:30:00 to 27-MAY-13 09:00:00 (CST-6)
Magnitude: 52.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

Hail in TAYLOR, IOWA
From 26-MAY-13 19:00:00 to 26-MAY-13 19:00:00 (CST-6)
Location: MERLE JCT
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in TAYLOR, IOWA
From 26-MAY-13 19:37:00 to 26-MAY-13 19:37:00 (CST-6)
Location: BEDFORD
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rainfall of three quarters of an inch as well.

Hail in TAYLOR, IOWA
From 26-MAY-13 19:21:00 to 26-MAY-13 19:21:00 (CST-6)
Location: GRAVITY
Magnitude: 1.25 
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hail in HUMBOLDT, IOWA
From 26-MAY-13 21:55:00 to 26-MAY-13 21:55:00 (CST-6)
Location: BRADGATE
Magnitude: 1.00 
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Rain in TAMA, IOWA
From 26-MAY-13 16:12:00 to 26-MAY-13 16:12:00 (CST-6)
Location: TOLEDO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Rainfall since midnight was 3.92 inches.

Tornado in RINGGOLD, IOWA
From 26-MAY-13 18:23:00 to 26-MAY-13 18:24:00 (CST-6)
Location: DIAGONAL
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A brief tornado touchdown occurred.

High Wind in JASPER, IOWA
From 27-MAY-13 09:00:00 to 27-MAY-13 10:00:00 (CST-6)
Magnitude: 40.00 MS
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in HARDIN, IOWA
From 27-MAY-13 06:30:00 to 27-MAY-13 07:30:00 (CST-6)
Magnitude: 40.00 MS
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Mesonet

Trees were blown down and outbuildings were damaged.

High Wind in BOONE, IOWA
From 27-MAY-13 08:00:00 to 27-MAY-13 10:00:00 (CST-6)
Magnitude: 40.00 ES
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Mesonet

Tree limbs were blown down as well as a few power lines.

Flood in JASPER, IOWA
From 26-MAY-13 11:01:00 to 27-MAY-13 07:30:00 (CST-6)
Location: METZ
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Public

North Skunk River was out of its banks along I-80.

Flash Flood in MARSHALL, IOWA
From 26-MAY-13 14:35:00 to 26-MAY-13 20:30:00 (CST-6)
Location: CLEMONS
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Minerva Creek out of its banks and flooding 50 acres near 148th and S52.  Water approaching the bridge.  Gravel road 155th was under water.

Flash Flood in STORY, IOWA
From 26-MAY-13 14:55:00 to 26-MAY-13 18:45:00 (CST-6)
Location: ZEARING
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: COOP Observer

NWS CO-OP observer and Emergency Manager report flash flooding in and near Zearing.  Highway 65 is under water in two places, including south 140th St.  County pavement E18 is closed in several places east and west of Zearing.

Flash Flood in MARSHALL, IOWA
From 26-MAY-13 15:30:00 to 26-MAY-13 20:30:00 (CST-6)
Location: LURAY
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Marshall County dispatch reports flooded roads in Marshalltown and the northern part of the county.  Major Highways 14 and 146 are under water and closed with numerous stranded vehicles in Marshalltown.

Flash Flood in MARSHALL, IOWA
From 26-MAY-13 17:10:00 to 26-MAY-13 20:30:00 (CST-6)
Location: HAVERHILL
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Marshall County Sheriff reports that Highway 14 remained closed due to flooding north of Marshalltown.  Highway 330 south of Albion is also closed.

Flood in MAHASKA, IOWA
From 26-MAY-13 23:45:00 to 27-MAY-13 12:30:00 (CST-6)
Location: NEW SHARON
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Highway 63 east of town and highway 146 north of town flooded by the North Skunk River.

Flash Flood in POWESHIEK, IOWA
From 26-MAY-13 17:30:00 to 26-MAY-13 20:45:00 (CST-6)
Location: SHERIDAN
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Newburg road near intersection of Highway F17 and Highway 63 is closed for a distance of about 100 yards.

Hail in POLK, IOWA
From 26-MAY-13 17:45:00 to 26-MAY-13 17:50:00 (CST-6)
Location: (DSM)DES MOINES INTL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Special observation from the airport observer.

Flash Flood in POWESHIEK, IOWA
From 26-MAY-13 19:15:00 to 26-MAY-13 20:45:00 (CST-6)
Location: MALCOLM
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Flash flooding reported on 90th St. between 360th and 370th Ave.

Flood in POWESHIEK, IOWA
From 26-MAY-13 19:15:00 to 27-MAY-13 09:30:00 (CST-6)
Location: FOREST HOME
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Numerous road closings due to flooding throughout Poweshiek County including 400th Ave west of Grinnell and several roads in the Searsboro and Montezuma area.

Flood in JASPER, IOWA
From 26-MAY-13 19:40:00 to 27-MAY-13 03:30:00 (CST-6)
Location: KELLOGG
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: State Official

Twenty sections of county roads were closed due to flooding, many along the North Skunk River.

Flood in MAHASKA, IOWA
From 26-MAY-13 20:45:00 to 27-MAY-13 07:30:00 (CST-6)
Location: NEW SHARON
Flood cause: Heavy Rain
Property damage: 150.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Highway 146 is closed from Highway 63 at New Sharon north to the Poweshiek County line due to flooding on the North Skunk River.

Flash Flood in GUTHRIE, IOWA
From 27-MAY-13 03:15:00 to 27-MAY-13 08:00:00 (CST-6)
Location: BAYARD
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Highway 25 railroad underpass flooded.  Highway has been closed.

Flash Flood in BUTLER, IOWA
From 27-MAY-13 08:37:00 to 27-MAY-13 12:45:00 (CST-6)
Location: NEW HARTFORD
Flood cause: Dam / Levee Break
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Terrace Ave, a gravel road levee, is failing and water is flowing into New Hartford.

Flood in BUTLER, IOWA
From 26-MAY-13 21:50:00 to 27-MAY-13 12:30:00 (CST-6)
Location: PARKERSBURG
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 0.00K
Reported by: COOP Observer

Beaver Creek out of its banks and flooding about a mile long section of Iowa Highway 57 west of Parkersburg.  Iowa DOT has already closed that section of the highway with water reaching several houses.