Tornado and Flash Flooding in Iowa, June 26 to 27, 2011

Name: Tornado and Flash Flooding in Iowa, June 26 to 27, 2011
Start: 2011-06-26T15:55
End: 2011-06-27T01:15
Location: Iowa

June 26 to 27, 2011 · NWS DMX · 77 events in 34 counties and zones

S. A strong surge of moisture took place during the day on the 26th, with precipitable water values rising to over 2 inches by evening.

Where it happened

Every event with a place to put it; 13 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $3.6 million
Crop damage: $135,000
Events: 77

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS DMX wrote it up.

A dynamic pattern was once again in place over the central U.S. A strong surge of moisture took place during the day on the 26th, with precipitable water values rising to over 2 inches by evening. The airmass became very unstable with the lifted index falling to around -8 and CAPE in excess of 4000 J/kg. The atmosphere was quite warm with the freezing level between 15,000 and 16,000 feet. CAPE in the -10 to -30 C layer of the atmosphere was around 600 J/kg. Downdraft CAPE was quite high, in the 1200 to 1500 J/kg range. Considerable shear was available with shear in the 50 to 65 kt range. Meanwhile, a strong mid level trough of low pressure approached the central U.S. along with a moderate cold front approaching from the northwest. During the night, the low level jet increased to 70 kts, further feeding the thunderstorms. A large complex of thunderstorms developed across South Dakota into Nebraska. It moved southeast into the rich air over Iowa and accelerated, becoming a derecho. A large area of high winds developed with widespread wind gusts of 60 to 75 MPH, mainly over the southwest half of the CWA. The storms also produced hail at most locations as it passed. Most of the hail was around an inch or so in diameter. A smaller area of thunderstorms formed over southeast Iowa, ahead of the main area. These storms produced hail up to golf ball in size, along with 60 MPH winds during the early evening. The largest hail reported was 2 inches in diameter in Cincinnati in Appanoose County. The storms produced copious rainfall in spite of their rapid movement. Flash flooding was reported in Union, Adair, Davis, and Adams Counties. For the most part the flash flooding was relatively minor, limited to water flowing rapidly over roads. In Davis County at Bloomfield, water blew off manhole covers and was deep enough to nearly reach the tops of car roofs. The thunderstorm winds caused widespread damage to trees and power lines. A semi-truck was overturned on Highway 141 west of Woodward by the winds. Another was overturned in Carroll County on U.S. highway 30. A high wind event also took place with the storm complex as a wake low formed. Strong easterly winds developed with wind speeds in the 60 to 75 MPH range common. The strongest winds occurred in Webster County at Callendar. Winds of 80 to 90 MPH blew down mailbox posts, blew down trees onto houses, and picked up a swing set and blew it through the window of a house. Tree and power line damage was quite widespread over a 7 county area. One tornado touched down in Carroll County south of Halbur. A narrow swath of damage occurred from about one quarter mile south of the intersection of Granite Ave and County Road E53, with the roof blown off a hog confinement building just southeast of the intersection. Minor damage continued along a path 2.5 miles long to the east with another roof partially blown off of a Morton building just southwest of the intersection of County Road E53 and Ivy Ave. The tornado lifted about one quarter of a mile southeast of the intersection.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before the first event at Jun 26, 2:25 PM CST, 1 hour 30 minutes earlier.

Area forecast discussion, Jun 26, 2:25 PM CST, 1 hour 30 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
325 PM CDT SUN JUN 26 2011

.SHORT TERM /TONIGHT/...
ACTIVE NIGHT IN STORE FOR MUCH OF CENTRAL IA AS SHORTWAVE PASSES OUT
OF THE ROCKIES AND THROUGH THE PLAINS.  WILL SEE STRONG WAA/THETA-E
ADVECTION AHEAD OF THE SHORTWAVE AS 850MB FLOW INTENSIFIES AHEAD OF
THE SYSTEM.  INITIAL THOUGHT IS THAT DEVELOPMENT WILL OCCUR ALONG
THE INSTABILITY AXIS AND WILL BE FED BY THE STRONG THETA-E
ADVECTION.  THIS WILL LIKELY OCCUR IN THE SOUTHERN HALF OF THE CWA
LATE THIS AFTERNOON INTO THE EVENING.  CONCERN OF BOTH SEVERE AND
HYDRO POTENTIAL WITH THIS ACTIVITY AND WILL DISCUSS THE HYDRO
SITUATION BELOW.  AS FOR SEVERE POTENTIAL...HAIL AND WIND REMAIN THE
HIGHEST POTENTIAL THROUGH THE EVENING AND OVERNIGHT HOURS WITH SOME
LIMITED TORNADO THREAT THIS EVENING IN THE SOUTHWEST QUARTER.  MAIN
CONCERN FOR TORNADO DEVELOPMENT IS NEAR SURFACE INSTABILITY WHICH
WAS NON-EXISTENT ON THE 18Z KOAX.  MAY HAVE ENOUGH TIME IN THE
SOUTHWEST FOR THE WARM FRONT TO APPROACH AND LEAD TO SOME SURFACE
BASED CONVECTION...BUT TIME WILL BE SHORT AND LIKELY LIMITED TO THE
EVENING HOURS.  OTHERWISE...PROGRESSIVE MOVING LINE OF THUNDERSTORMS
NOW IN NORTH CENTRAL NEBRASKA IS EXPECTED TO TRAVEL ALONG THE
INSTABILITY GRADIENT THIS EVENING WITH DAMAGING WINDS AND LARGE HAIL
INTO WESTERN AND SOUTHERN IA.  SOME ADDITIONAL CONVECTION FARTHER
NORTH IS ALSO EXPECTED BUT LIKELY NOT AS INTENSE DUE TO LOWER
INSTABILITY.  SOME ADDITIONAL CONVECTION IS EXPECTED AFTER THIS
PROGRESSIVE SYSTEM BUT LOCATION AND TIMING WILL BE DIFFICULT TO
DETERMINE DUE TO THE INITIAL SYSTEMS PASSING THROUGH.

.LONG TERM /MONDAY THROUGH SUNDAY/...
MAIN CONCERN WILL BE MOIST TROPICAL AIRMASS THAT COULD PUSH
TEMPERATURES/HEAT INDICES IN THE DANGEROUS CATEGORY FOR THURSDAY AND
FRIDAY.
MONDAY MORNING THROUGH WEDNESDAY...MATURE MCS IS EXPECTED TO BE
LOCATED ACROSS EASTERN IOWA BY 12Z TOMORROW MORNING. THIS SHOULD BE
QUICK TO MOVE OUT AS PROGRESSIVE SHORTWAVE SLIDES ACROSS THE GREAT
LAKES REGION. SUBSIDENCE ON THE BACK SIDE OF THIS WAVE WILL DRY OUT
THE MID LEVELS...AND EXPECT CLOUDS TO MIX OUT FROM THE NORTHWEST TO
SOUTHEAST THROUGHOUT THE AFTERNOON HOURS. SURFACE HIGH PRESSURE WITH
CLEAR SKIES AND CALM WINDS COULD LEAD TO SOME PATCHY FOG TUESDAY
MORNING. BUT GIVEN THE DRY AIRMASS IN PLACE AND HIGH SUN
ANGLE...CONFIDENCE IS TOO LOW TO MENTION FOG IN THE GRIDS AS A SOLE
RESULT OF RADIATIONAL COOLING. AFTER A PICTURE PERFECT DAY ON
TUESDAY...THE UPPER LEVEL RIDGE WILL SLIDE EAST WITH WARM AIR
ADVECTION DEVELOPING ACROSS THE REGION ON THE BACK SIDE OF THE HIGH.
THEREFORE HAVE SLIGHT CHANCE POPS ACROSS THE MISSOURI RIVER VALLEY
EARLY WEDNESDAY MORNING.
THURSDAY THOUGH SUNDAY...H850 TEMPS WILL WARM FROM 20C 00Z
THURSDAY....TO UPPER 20S BY 00Z FRIDAY. THIS WARM LAYER WILL
SUPPRESS ANY CONVECTION DESPITE SBCAPES RANGING FROM 4000-5000J/KG.
THURS/FRI AFTERNOON TEMPS ARE EXPECTED TO CLIMB INTO THE LOWER
90S...WITH DEWPOINTS IN THE MID 70S. THIS OPPRESSIVE AIRMASS MAY
RESULT EXCESSIVE HEAT PRODUCTS BEING ISSUED AS EVENT NEARS. THE
STORM TRACK SHIFTS NORTHWARD WITH A SHORTWAVE MOVING ACROSS THE
DAKOTAS INTO CANADA ON FRIDAY. THIS WILL SWING A DYING COLD FRONT
THOUGH THE CWA FRIDAY EVENING WHICH WILL STALL OUT ACROSS SOUTHERN
IOWA. LEE SIDE TROUGHING ACROSS WESTERN KANSAS WILL TRY TO BRING
THIS BOUNDARY NORTH AS A WARM FRONT...SO HAVE SLIGHT POPS ACROSS THE
SOUTH ON SATURDAY...AND INCREASING IN COVERAGE OVERNIGHT IN RESPONSE
TO THE THETA_E ADVECTION ASSOCIATED WITH THE STRENGTHENING LOW LEVEL
JET.

&&

.AVIATION...26/18Z
WILL SEE INCREASING WAA AND THETA-E ADVECTION INTO LATE AFTERNOON
AND TONIGHT AS WARM FRONT LIFTS TOWARD SOUTHERN IOWA.  ANTICIPATE
SOME THINNING OF MVFR CIGS DURING THE AFTERNOON WITH DAYTIME HEATING
BEFORE CONVECTION DEVELOPS BY LATE AFTERNOON/EARLY EVENING IN
SOUTHWEST IOWA.  ANTICIPATE WIDESPREAD CONVECTION OVERNIGHT IN
CENTRAL IOWA BEFORE A COLD FRONT PASSES THROUGH THE STATE ON MONDAY
MORNING.  ANTICIPATE WIDESPREAD MVFR TO IFR CIGS OVERNIGHT AND
RESTRICTED VISIBILITIES AS WELL WITH THUNDERSTORMS PASSING THROUGH
THE AREA.  MANY OF THE RESTRICTION WILL DISSIPATE ON MONDAY MORNING
AS THE COLD FRONT SWEEPS ACROSS THE STATE.  SFC WINDS WILL MAINLY BE
SOUTHEAST THIS AFTERNOON AND TONIGHT ALTHOUGH VARIABLE AND STRONG
GUSTS IN AND AROUND THUNDERSTORMS.  WINDS WILL INCREASE FROM THE
NORTHWEST ON MONDAY MORNING BEHIND THE FRONT.

&&

.HYDROLOGY...
WILL SEE STRONG THETA-E ADVECTION INTO THE STATE TONIGHT AS SYSTEM
PULLS OUT OF THE ROCKIES AND INTO THE PLAINS. INSTABILITY GRADIENT
IS EXPECTED TO PUSH INTO SOUTHERN IA THIS EVENING WITH THUNDERSTORMS
TRACKING NEAR THIS AREA.  GIVEN THE HEAVY RAINFALL YESTERDAY AND
PWATS APPROACHING 2 INCHES ALONG WITH ANTICIPATED HIGH RAINFALL
RATES AND AMOUNTS...HAVE GONE WITH A FLASH FLOOD WATCH IN THE
SOUTHERN HALF OF THE CWA WHERE GUIDANCE VALUES ARE GENERALLY BELOW 2
INCHES AND MANY AREAS CLOSE TO AN INCH. CERTAINLY WONT TAKE MUCH
PRECIPITATION FOR RENEWED HYDRO ISSUES INCLUDING RIVER FLOODING AS
WELL.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR ADAIR-ADAMS-
APPANOOSE-AUDUBON-BOONE-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-
DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-MADISON-MAHASKA-MARION-
MONROE-POLK-POWESHIEK-RINGGOLD-STORY-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE.

&&

SHORT TERM/HYDROLOGY...COGIL
LONG TERM...BEITLICH
AVIATION...COGIL

Hazardous weather outlook, Jun 26, 3:21 PM CST, 34 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
421 PM CDT SUN JUN 26 2011

IAZ044>048-057>062-070>075-081>086-092>097-271100-
CRAWFORD-CARROLL-GREENE-BOONE-STORY-AUDUBON-GUTHRIE-DALLAS-POLK-
JASPER-POWESHIEK-CASS-ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-
UNION-CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-
APPANOOSE-DAVIS-
421 PM CDT SUN JUN 26 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TONIGHT

THUNDERSTORMS WILL OVERSPREAD THE AREA TONIGHT. THE STORMS WILL BE
CAPABLE OF PRODUCING WINDS TO 70 MPH...PING PONG SIZED HAIL AND
VERY HEAVY RAINFALL. A TORNADO OR TWO WILL BE POSSIBLE DURING THE
EVENING HOURS NEAR THE MISSOURI BORDER.

A FLASH FLOOD WATCH IS IN EFFECT FOR THE AREA TONIGHT. PLEASE
REFER TO THE NATIONAL WEATHER SERVICE WEBSITE AT
WEATHER.GOV/DESMOINES FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS CHANCES WILL CONTINUE INTO MONDAY MORNING...WITH
THE POSSIBILITY OF A FEW SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WINDS. STORMS MAY ALSO PRODUCE LOCALLY HEAVY RAINFALL.

ADDITIONAL CHANCES FOR THUNDERSTORMS WILL TUESDAY NIGHT AND AGAIN
LATE FRIDAY THROUGH SATURDAY. AT THIS TIME THE THREAT FOR SEVERE
WEATHER APPEARS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED TONIGHT.

IAZ004-005-015-024-035-036-271100-
EMMET-KOSSUTH-PALO ALTO-HUMBOLDT-WEBSTER-HAMILTON-
421 PM CDT SUN JUN 26 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TONIGHT

THUNDERSTORMS ARE EXPECTED TONIGHT. SOME SEVERE WEATHER IS
EXPECTED FROM QUARTER SIZED HAIL AND DAMAGING WINDS TO 65 MPH.
HEAVY RAINFALL IS ALSO POSSIBLE.

RIVER FLOOD WARNINGS ARE IN EFFECT FOR PARTS OF THE UPPER DES
MOINES RIVER BASIN. PLEASE REFER TO THE NATIONAL WEATHER SERVICE
WEBSITE AT WEATHER.GOV/DESMOINES FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS CHANCES WILL CONTINUE MONDAY MORNING BUT THE SEVERE
WEATHER THREAT APPEARS LOW AT THIS TIME. ADDITIONAL CHANCES FOR
THUNDERSTORMS WILL TUESDAY NIGHT AND AGAIN LATE FRIDAY THROUGH
SATURDAY. AT THIS TIME THE THREAT FOR SEVERE WEATHER APPEARS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY TONIGHT.

IAZ006-007-016-017-023-025>028-033-034-037>039-049-050-271100-
WINNEBAGO-WORTH-HANCOCK-CERRO GORDO-POCAHONTAS-WRIGHT-FRANKLIN-
BUTLER-BREMER-SAC-CALHOUN-HARDIN-GRUNDY-BLACK HAWK-MARSHALL-TAMA-
421 PM CDT SUN JUN 26 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TONIGHT

THUNDERSTORMS ARE EXPECTED TONIGHT. SOME SEVERE WEATHER IS
EXPECTED FROM QUARTER SIZED HAIL AND DAMAGING WINDS TO 65 MPH.
HEAVY RAINFALL IS ALSO POSSIBLE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS CHANCES WILL CONTINUE MONDAY MORNING BUT THE SEVERE
WEATHER THREAT APPEARS LOW AT THIS TIME. ADDITIONAL CHANCES FOR
THUNDERSTORMS WILL TUESDAY NIGHT AND AGAIN LATE FRIDAY THROUGH
SATURDAY. AT THIS TIME THE THREAT FOR SEVERE WEATHER APPEARS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY TONIGHT.

CC

In the hours before

Special weather statement, Jun 26, 2:34 PM CST, 1 hour 21 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
334 PM CDT SUN JUN 26 2011

IAZ070-071-081-262100-
ADAIR-ADAMS-CASS-
334 PM CDT SUN JUN 26 2011

...SPECIAL WEATHER STATEMENT...

AT 331 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER SOUTH CENTRAL CASS COUNTY...MOVING EAST AT
40 MPH.

HAIL UP TO ONE HALF INCH DIAMETER...AND OCCASIONAL CLOUD TO GROUND
LIGHTNING...ARE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
  CUMBERLAND...         MASSENA...            BRIDGEWATER...
  FONTANELLE...

STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK SHELTER IN A
STURDY STRUCTURE UNTIL THIS STORM HAS PASSED.

JUNGBLUTH

Special weather statement, Jun 26, 3:04 PM CST, 51 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
404 PM CDT SUN JUN 26 2011

IAZ070>072-081-082-262130-
ADAIR-ADAMS-CASS-MADISON-UNION-
404 PM CDT SUN JUN 26 2011

...SPECIAL WEATHER STATEMENT...

AT 358 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER SOUTH CENTRAL ADAIR COUNTY...MOVING EAST AT
45 MPH.

ONE HALF INCH DIAMETER HAIL...FREQUENT CLOUD TO GROUND
LIGHTNING...AND HEAVY DOWNPOURS...ARE LIKELY WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
  MACKSBURG...          WINTERSET...          EAST PERU...

STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK SHELTER IN A
STURDY STRUCTURE UNTIL THIS STORM HAS PASSED. SOILS ARE
SATURATED...SO BE ALERT FOR PONDING OF WATER AND FILLING DITCHES.

JUNGBLUTH

Local storm report, Jun 26, 3:41 PM CST, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
441 PM CDT SUN JUN 26 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0438 PM     TSTM WND GST     4 NNW CRESTON AIRPORT   41.07N 94.38W
06/26/2011  E55 MPH          UNION              IA   TRAINED SPOTTER

            SMALL TREES BENDING...HORIZONTAL RAIN...STRONG WINDS

&&

REV

The radar

The Des Moines radar (KDMX), 90 km away, was scanning. The volume nearest the first event began at 21:54 UTC.

Open the radar archive at this moment

Event by event

41 thunderstorm wind, 15 hail, 13 high wind, 6 flash flood, 1 tornado, 1 heavy rain. Local standard time, as filed.

Hail, Union

When: June 26, 3:55 PM CST
Where: Union County, 1.04 mi E of Creston
Measured: 1 in hail
Property damage: $1,000
Crop damage: $10,000
Reported by: Law Enforcement
Coordinates: 41.070, -94.350

Flash Flood, Union

When: June 26, 4:25 PM CST to 10:00 PM CST
Where: Union County, 2.94 mi NW of Creston to 3.54 mi WNW of Creston
Cause: Heavy Rain
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 41.100, -94.410

Water flowing over the road at several locations near the intersection of 140th Street and Highway 25.

Hail, Lucas

When: June 26, 4:25 PM CST
Where: Lucas County, 0.52 mi E of Chariton
Measured: 1 in hail
Property damage: $1,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.020, -93.310

Hail, Clarke

When: June 26, 4:55 PM CST
Where: Clarke County, 3.45 mi S of Woodburn
Measured: 1 in hail
Property damage: $1,000
Crop damage: $10,000
Reported by: Fire Department/Rescue
Coordinates: 40.970, -93.600

Hail, Cass

When: June 26, 5:00 PM CST
Where: Cass County, 4.17 mi NE of Dewey
Measured: 1 in hail
Crop damage: $10,000
Reported by: Law Enforcement
Coordinates: 41.220, -94.710

Nickel to quarter hail relayed to law enforcement from the public.

Hail, Lucas

When: June 26, 5:04 PM CST
Where: Lucas County, 0.52 mi W of Derby
Measured: 0.88 in hail
Crop damage: $5,000
Reported by: Public
Coordinates: 40.930, -93.460

Thunderstorm Wind, Lucas

When: June 26, 5:04 PM CST
Where: Lucas County, 0.87 mi NE of Chariton
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 41.030, -93.310

Electric pole partially blown over on Highway 14. Wires were sparking.

Thunderstorm Wind, Adair

When: June 26, 5:12 PM CST
Where: Adair County, 2.07 mi N of Fisk
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.230, -94.530

Three to four inch diameter tree branches blown down. Pea size hail as well.

Hail, Appanoose

When: June 26, 5:21 PM CST
Where: Appanoose County, Centerville
Measured: 1.75 in hail
Property damage: $50,000
Crop damage: $5,000
Reported by: Trained Spotter
Coordinates: 40.730, -92.870

Quarter to golf ball size hail.

Hail, Appanoose

When: June 26, 5:22 PM CST
Where: Appanoose County, 0.87 mi NE of Centerville
Measured: 1 in hail
Property damage: $5,000
Crop damage: $5,000
Reported by: Trained Spotter
Coordinates: 40.740, -92.860

Nickel to quarter size hail covering the parking lot.

Hail, Appanoose

When: June 26, 5:23 PM CST
Where: Appanoose County, Centerville
Measured: 1 in hail
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 40.730, -92.870

Thunderstorm Wind, Appanoose

When: June 26, 5:49 PM CST
Where: Appanoose County, Centerville
Measured: 52 kt (60 mph) estimated gust
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 40.730, -92.870

Trees damaged and power lines were down.

Flash Flood, Adams

When: June 26, 6:04 PM CST to 10:00 PM CST
Where: Adams County, 2.22 mi SW of Williamson to 1.12 mi NNE of Prescott
Cause: Heavy Rain
Property damage: $10,000
Reported by: Emergency Manager
Coordinates: 41.131, -94.605

Emergency Manager reported several secondary roads were flash flooded in northeast Adams County.

Hail, Appanoose

When: June 26, 6:07 PM CST
Where: Appanoose County, 0.52 mi W of Udell
Measured: 1 in hail
Property damage: $1,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 40.780, -92.740

Flash Flood, Adams

When: June 26, 6:20 PM CST to 10:00 PM CST
Where: Adams County, 4.86 mi S of Nevinville to 4.76 mi S of Nevinville
Cause: Heavy Rain
Property damage: $15,000
Reported by: Emergency Manager
Coordinates: 41.080, -94.530

One foot of water flowing over the intersection of Union and 150th Street.

Thunderstorm Wind, Davis

When: June 26, 6:29 PM CST
Where: Davis County, 2.07 mi S of Paris
Measured: 61 kt (70 mph) estimated gust
Property damage: $25,000
Reported by: Law Enforcement
Coordinates: 40.750, -92.570

Large trees were uprooted in the town of West Grove.

Flash Flood, Davis

When: June 26, 6:30 PM CST to June 27, 1:00 AM CST
Where: Davis County, 1.33 mi WNW of Bloomfield Arpt to 1.44 mi NNW of Bloomfield
Cause: Heavy Rain
Property damage: $250,000
Reported by: Fire Department/Rescue
Coordinates: 40.739, -92.442

Water nearly to the tops of cars in streets of Bloomfield. Manhole covers were blown off.

Thunderstorm Wind, Davis

When: June 26, 6:40 PM CST
Where: Davis County, Pulaski
Measured: 61 kt (70 mph) estimated gust
Property damage: $25,000
Reported by: Trained Spotter
Coordinates: 40.700, -92.270

Large trees were down in Pulaski from thunderstorm winds.

Thunderstorm Wind, Crawford

When: June 26, 7:11 PM CST
Where: Crawford County, 7 mi WSW of Dow City
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.900, -95.630

Tree limb damage was reported.

Thunderstorm Wind, Crawford

When: June 26, 7:28 PM CST
Where: Crawford County, 2 mi NW of Denison
Measured: 61 kt (70 mph) estimated gust
Property damage: $40,000
Reported by: Newspaper
Coordinates: 42.041, -95.378

High winds caused damage to a barn and some minor damage to a farm house.

Thunderstorm Wind, Crawford

When: June 26, 7:30 PM CST
Where: Crawford County, 0.51 mi E of Dow City
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Law Enforcement
Coordinates: 41.930, -95.490

Power lines were blown down.

Thunderstorm Wind, Crawford

When: June 26, 7:33 PM CST
Where: Crawford County, Denison
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 42.020, -95.350

Trees down in Denison and 2 miles west of town.

Thunderstorm Wind, Sac

When: June 26, 7:34 PM CST
Where: Sac County, 1.23 mi SE of Odebolt
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: Trained Spotter
Coordinates: 42.310, -95.250

Tree limb damage was reported.

Tornado, Carroll

When: June 26, 7:40 PM CST to 7:43 PM CST
Where: Carroll County, 2.81 mi S of Halbur to 2.84 mi WSW of Willey
Rating: EF1
Path length: 2.37 mi
Path width: 100 yd
Property damage: $100,000
Crop damage: $10,000
Reported by: NWS Storm Survey
Coordinates: 41.960, -94.980

An EF1 tornado was on the ground for a brief time with a path length of 2.5 miles due east. Width was up to 100 yards with peak wind estimated at around 95 mph. A roof was blown off a hog confinement building and Morton building with other damage in between.

Thunderstorm Wind, Carroll

When: June 26, 7:43 PM CST
Where: Carroll County, 1.03 mi E of Carroll
Measured: 52 kt (60 mph) measured gust
Property damage: $5,000
Reported by: Mesonet
Coordinates: 42.070, -94.860

Thunderstorm Wind, Carroll

When: June 26, 7:45 PM CST
Where: Carroll County, 0.51 mi E of Templeton
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.920, -94.940

Eight inch diameter tree limbs down.

Thunderstorm Wind, Audubon

When: June 26, 7:47 PM CST
Where: Audubon County, Audubon
Measured: 65 kt (75 mph) estimated gust
Property damage: $100,000
Reported by: Newspaper
Coordinates: 41.720, -94.930

High winds in Audubon caused damage to a local church. A structure holding the Ten Commandments was destroyed by the winds as they were torn down from the church.

Hail, Audubon

When: June 26, 7:51 PM CST
Where: Audubon County, 0.69 mi N of Audubon Arpt
Measured: 1 in hail
Crop damage: $10,000
Reported by: Law Enforcement
Coordinates: 41.710, -94.920

Thunderstorm Wind, Carroll

When: June 26, 7:55 PM CST
Where: Carroll County, 0.51 mi E of Templeton
Measured: 57 kt (66 mph) estimated gust
Property damage: $20,000
Reported by: Trained Spotter
Coordinates: 41.920, -94.940

Large tree limbs down with nickel hail as well.

Thunderstorm Wind, Greene

When: June 26, 8:00 PM CST
Where: Greene County, 6.21 mi W of Cooper
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.910, -94.470

Three to four inch diameter tree branches down.

Thunderstorm Wind, Adair

When: June 26, 8:11 PM CST
Where: Adair County, 0.52 mi E of Adair
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.500, -94.640

Trees and power lines down.

Thunderstorm Wind, Adair

When: June 26, 8:24 PM CST
Where: Adair County, 7.58 mi NNE of Howe
Measured: 57 kt (66 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.500, -94.320

Two foot diameter tree downed in Stuart.

Thunderstorm Wind, Dallas

When: June 26, 8:26 PM CST
Where: Dallas County, 1.7 mi ESE of Kennedy
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.610, -94.090

Trees and power lines down.

Thunderstorm Wind, Dallas

When: June 26, 8:27 PM CST
Where: Dallas County, 0.51 mi E of Perry Muni Arpt
Measured: 53 kt (61 mph) measured gust
Property damage: $5,000
Reported by: AWOS
Coordinates: 41.830, -94.160

Hail, Guthrie

When: June 26, 8:28 PM CST
Where: Guthrie County, 0.86 mi NW of Stuart
Measured: 0.75 in hail
Crop damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.510, -94.330

Thunderstorm Wind, Boone

When: June 26, 8:29 PM CST
Where: Boone County, 4.86 mi S of Berkley
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: Public
Coordinates: 41.880, -94.110

Large 2 to 3 foot diameter oak tree blown down.

Thunderstorm Wind, Dallas

When: June 26, 8:30 PM CST
Where: Dallas County, 1.69 mi WNW of Woodward
Measured: 52 kt (60 mph) estimated gust
Property damage: $10,000
Reported by: Emergency Manager
Coordinates: 41.860, -93.960

Semi-truck overturned on Highway 141.

Thunderstorm Wind, Dallas

When: June 26, 8:30 PM CST
Where: Dallas County, 0.86 mi SW of Adel
Measured: 57 kt (66 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.610, -94.030

Six inch tree limbs down in the town of Adel.

Thunderstorm Wind, Boone

When: June 26, 8:30 PM CST
Where: Boone County, 1.38 mi S of Boone
Measured: 52 kt (60 mph) estimated gust
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 42.050, -93.880

Six inch diameter branch down, patio furniture blown throughout the yard. Loss of power for 5 minutes.

Hail, Madison

When: June 26, 8:35 PM CST
Where: Madison County, 5.17 mi W of Earlham
Measured: 1 in hail
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.500, -94.230

Heavy rain and 40 MPH winds as well.

Thunderstorm Wind, Boone

When: June 26, 8:35 PM CST
Where: Boone County, 0.86 mi SW of Boxholm
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Law Enforcement
Coordinates: 42.170, -94.110

Pea hail accompanied the high wind.

High Wind, Sac

When: June 26, 8:40 PM CST to 11:40 PM CST
Where: Sac forecast zone
Measured: 57 kt (66 mph) estimated gust
Property damage: $100,000
Reported by: Trained Spotter
Coordinates: 42.386, -95.105 (the zone’s center; the record gives no point)

High Wind, Crawford

When: June 26, 8:40 PM CST to 11:40 PM CST
Where: Crawford forecast zone
Measured: 51 kt (59 mph) measured gust
Property damage: $75,000
Reported by: AWOS
Coordinates: 42.037, -95.382 (the zone’s center; the record gives no point)

High Wind, Carroll

When: June 26, 8:40 PM CST to 11:40 PM CST
Where: Carroll forecast zone
Measured: 61 kt (70 mph) measured gust
Property damage: $150,000
Reported by: Mesonet
Coordinates: 42.036, -94.861 (the zone’s center; the record gives no point)

Law Enforcement also reported a semi-truck blown over on Highway 30 in Carroll at 2045 CST.

Thunderstorm Wind, Adair

When: June 26, 8:40 PM CST
Where: Adair County, 7.58 mi NNE of Howe
Measured: 57 kt (66 mph) estimated gust
Property damage: $15,000
Reported by: Emergency Manager
Coordinates: 41.500, -94.320

Three inch branches down in Stuart blocking the street and hitting a car.

High Wind, Pocahontas

When: June 26, 8:40 PM CST to 11:40 PM CST
Where: Pocahontas forecast zone
Measured: 61 kt (70 mph) estimated gust
Property damage: $150,000
Reported by: Newspaper
Coordinates: 42.734, -94.679 (the zone’s center; the record gives no point)

High Wind, Palo Alto

When: June 26, 8:40 PM CST to 11:40 PM CST
Where: Palo Alto forecast zone
Measured: 61 kt (70 mph) estimated gust
Property damage: $150,000
Reported by: Newspaper
Coordinates: 43.082, -94.678 (the zone’s center; the record gives no point)

High Wind, Kossuth

When: June 26, 8:40 PM CST to 11:40 PM CST
Where: Kossuth forecast zone
Measured: 61 kt (70 mph) estimated gust
Property damage: $150,000
Reported by: Newspaper
Coordinates: 43.204, -94.207 (the zone’s center; the record gives no point)

High Wind, Humboldt

When: June 26, 8:40 PM CST to 11:40 PM CST
Where: Humboldt forecast zone
Measured: 61 kt (70 mph) estimated gust
Property damage: $150,000
Reported by: Newspaper
Coordinates: 42.777, -94.207 (the zone’s center; the record gives no point)

High Wind, Emmet

When: June 26, 8:40 PM CST to 11:40 PM CST
Where: Emmet forecast zone
Measured: 61 kt (70 mph) estimated gust
Property damage: $150,000
Reported by: Newspaper
Coordinates: 43.378, -94.678 (the zone’s center; the record gives no point)

Thunderstorm Wind, Polk

When: June 26, 8:47 PM CST
Where: Polk County, 0.86 mi NE of Windsor Hgts
Measured: 55 kt (63 mph) measured gust
Property damage: $5,000
Reported by: NWS Employee
Coordinates: 41.610, -93.710

Thunderstorm Wind, Warren

When: June 26, 8:50 PM CST
Where: Warren County, 1.04 mi E of Norwalk
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.480, -93.660

Estimated 65 MPH winds with 3 to 6 inch diameter tree branches down.

Thunderstorm Wind, Polk

When: June 26, 8:52 PM CST
Where: Polk County, 1.38 mi S of Des Moines
Measured: 53 kt (61 mph) measured gust
Property damage: $10,000
Reported by: Mesonet
Coordinates: 41.580, -93.620

Measured by television station KCCI.

Thunderstorm Wind, Story

When: June 26, 8:52 PM CST
Where: Story County, 4.87 mi NNW of Gilbert
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 42.180, -93.700

Three inch diameter tree branches down.

Hail, Union

When: June 26, 9:05 PM CST
Where: Union County, 0.87 mi SE of Creston
Measured: 1 in hail
Property damage: $1,000
Crop damage: $10,000
Reported by: Emergency Manager
Coordinates: 41.060, -94.360

Thunderstorm Wind, Warren

When: June 26, 9:05 PM CST
Where: Warren County, 1.38 mi N of Norwalk
Measured: 61 kt (70 mph) estimated gust
Property damage: $25,000
Reported by: Emergency Manager
Coordinates: 41.500, -93.680

Numerous trees and power lines downed across town.

Thunderstorm Wind, Polk

When: June 26, 9:06 PM CST
Where: Polk County, 0.52 mi E of (Dsm)des Moines Intl
Measured: 50 kt (58 mph) measured gust
Property damage: $2,000
Reported by: ASOS
Coordinates: 41.530, -93.660

Flash Flood, Appanoose

When: June 26, 9:11 PM CST to June 27, 1:00 AM CST
Where: Appanoose County, 2.07 mi S of Dean to 1.59 mi SSE of Dean
Cause: Heavy Rain
Property damage: $100,000
Reported by: Law Enforcement
Coordinates: 40.590, -92.770

Bridge damage on 610th Street from the creek.

Heavy Rain, Warren

When: June 26, 9:14 PM CST
Where: Warren County, 1.32 mi NNE of Carlisle
Reported by: Emergency Manager
Coordinates: 41.518, -93.493

Ponded water a few inches deep was over portions of the road on SE Avon Road in Carlisle.

Thunderstorm Wind, Marshall

When: June 26, 9:15 PM CST
Where: Marshall County, Rhodes
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.930, -93.180

Tree branches down.

Flash Flood, Appanoose

When: June 26, 9:30 PM CST to June 27, 1:00 AM CST
Where: Appanoose County, 2.76 mi S of Cincinnati to 1.41 mi SSE of Coal City
Cause: Heavy Rain
Property damage: $500,000
Crop damage: $20,000
Reported by: Department of Highways
Coordinates: 40.590, -92.928

Several roads and bridges washed out in various locations across the southeast part of the county.

Thunderstorm Wind, Marion

When: June 26, 9:31 PM CST to 9:35 PM CST
Where: Marion County, Knoxville
Measured: 54 kt (62 mph) measured gust
Property damage: $5,000
Reported by: AWOS
Coordinates: 41.320, -93.100

Thunderstorm Wind, Marion

When: June 26, 9:34 PM CST
Where: Marion County, Knoxville
Measured: 61 kt (70 mph) estimated gust
Property damage: $10,000
Reported by: Emergency Manager
Coordinates: 41.320, -93.100

Power lines and poles down.

Thunderstorm Wind, Marion

When: June 26, 9:35 PM CST
Where: Marion County, Knoxville
Measured: 57 kt (66 mph) estimated gust
Property damage: $15,000
Reported by: Trained Spotter
Coordinates: 41.320, -93.100

Trees down in the town square of Knoxville.

Thunderstorm Wind, Marion

When: June 26, 9:38 PM CST
Where: Marion County, 0.86 mi SE of Pella
Measured: 63 kt (72 mph) measured gust
Property damage: $25,000
Reported by: AWOS
Coordinates: 41.410, -92.920

Thunderstorm Wind, Marion

When: June 26, 9:40 PM CST
Where: Marion County, 0.86 mi SE of Pella
Measured: 67 kt (77 mph) measured gust
Property damage: $30,000
Reported by: Trained Spotter
Coordinates: 41.410, -92.920

Hail, Clarke

When: June 26, 9:40 PM CST
Where: Clarke County, Osceola
Measured: 1.25 in hail
Property damage: $1,000
Reported by: Broadcast Media
Coordinates: 41.030, -93.780

Public submitted a picture of the hail being measured from the night before to KCCI's ulocal page.

Thunderstorm Wind, Marion

When: June 26, 9:44 PM CST
Where: Marion County, Bussey
Measured: 57 kt (66 mph) measured gust
Property damage: $20,000
Reported by: Mesonet
Coordinates: 41.200, -92.900

Thunderstorm Wind, Monroe

When: June 26, 9:52 PM CST
Where: Monroe County, 1.25 mi ENE of Lovilia
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Law Enforcement
Coordinates: 41.140, -92.910

Large trees blown down and cable wires hanging low.

Hail, Appanoose

When: June 26, 10:00 PM CST
Where: Appanoose County, Cincinnati
Measured: 2 in hail
Property damage: $50,000
Crop damage: $5,000
Reported by: Law Enforcement
Coordinates: 40.630, -92.920

Thunderstorm Wind, Mahaska

When: June 26, 10:06 PM CST
Where: Mahaska County, 0.86 mi SE of Oskaloosa
Measured: 55 kt (63 mph) estimated gust
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.290, -92.640

From KBOE radio station reported by Weather Eye.

High Wind, Calhoun

When: June 26, 10:15 PM CST to June 27, 1:15 AM CST
Where: Calhoun forecast zone
Measured: 61 kt (70 mph) measured gust
Property damage: $100,000
Reported by: Mesonet
Coordinates: 42.385, -94.640 (the zone’s center; the record gives no point)

High Wind, Greene

When: June 26, 10:15 PM CST to June 27, 1:15 AM CST
Where: Greene forecast zone
Measured: 61 kt (70 mph) estimated gust
Property damage: $100,000
Reported by: Law Enforcement
Coordinates: 42.036, -94.397 (the zone’s center; the record gives no point)

High Wind, Webster

When: June 26, 10:15 PM CST to June 27, 1:15 AM CST
Where: Webster forecast zone
Measured: 74 kt (85 mph) estimated gust
Property damage: $500,000
Reported by: Amateur Radio
Coordinates: 42.428, -94.182 (the zone’s center; the record gives no point)

High Wind, Hamilton

When: June 26, 10:15 PM CST to June 27, 1:15 AM CST
Where: Hamilton forecast zone
Measured: 59 kt (68 mph) estimated gust
Property damage: $100,000
Reported by: Broadcast Media
Coordinates: 42.384, -93.707 (the zone’s center; the record gives no point)

High Wind, Wright

When: June 26, 10:15 PM CST to June 27, 1:15 AM CST
Where: Wright forecast zone
Measured: 59 kt (68 mph) estimated gust
Property damage: $100,000
Reported by: Newspaper
Coordinates: 42.733, -93.735 (the zone’s center; the record gives no point)

Thunderstorm Wind, Wapello

When: June 26, 10:25 PM CST
Where: Wapello County, 0.52 mi W of Ottumwa
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.020, -92.410

Tree limbs damaged.

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.
Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Iowa in 2011 Every state in 2011 This day in weather history The tornado archive for Iowa, 2011 Warnings in Iowa, June 2011

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 304560, 304553, 304561, 304562, 304563, 304564, 304605, 304609, 304565, 304566, 304567, 304587, 321933, 304568, 304551, 304590, 304550, 304591, 304578, 317926, 304592, 304593, 304579, 304542, 304569, 304595, 317928, 304554, 304594, 304589, 304580, 304600, 304581, 304570, 304555, 304607, 304597, 304598, 304601, 304556, and more.