Flash Flooding and Hail in Iowa, June 23, 2009

Name: Flash Flooding and Hail in Iowa, June 23, 2009
Start: 2009-06-23T12:37
End: 2009-06-23T22:30
Location: Iowa

June 23, 2009 · NWS DMX · 95 events in 26 counties and zones

Where it happened

Every event with a place to put it; 1 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: $832,000
Crop damage: $295,000
Events: 95

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 very unstable airmass was in place over Iowa during the afternoon of the 23rd. Surface temperatures soared to the low to mid 90s in most areas, with dew point temperatures in the upper 70s to mid 80s. This resulted in most unstable CAPE values of 5000-8000 J/kg and lifted indices in the -10 to -14 C range. The LCL was relatively high in the 1000-1500 meter range. Downdraft CAPE was between 1400 and 1700 J/kg and there was a significant amount of CAPE in the -10 to -30 C layer of the atmosphere of 1000-1600 J/kg. The atmosphere was weakly sheared with 25 to 35 kts of effective shear. Shear in the zero to 3 km layer was between 50 and 250 J/kg, resulting in considerable rotation of thunderstorm cells. The freezing level was quite high, at 14,000 feet. Considerable moisture was available through a deep layer of the atmosphere with precipitable water values of 1.75 to 2 inches. Thunderstorms developed over the northwest part of Iowa by early afternoon. The storms became severe and dropped southeast into the most unstable air to the east and south of the complex. The primary mode of severe weather with this event was in the form of high winds and hail. Some of the hail reached golf ball in size, however with the warm atmospheric conditions much of the hail remained below severe levels. High winds were reported all along the leading edge of the thunderstorm complex, with numerous reports in the 60 to 70 MPH range. There were two areas where the most significant damage occurred. The first was in the Waterloo, Cedar Falls, and Hudson areas of northeast Iowa. A beta bow element pushed into the area resulting in more widespread wind damage. Some of the damage was similar to what one might expect with a weak tornado. The second area was over Dallas County. High winds caused considerable damage from around Dallas Center, west to the county line. An old airport field was hit by the winds with considerable damage to equipment and hangars. Winds were estimated to be at least 80 MPH. Later in the event, some of the storm cells collapsed with a local high wind event occurring in Hamilton County. Two semi-tractor trailer trucks were blown over on Interstate 35 between mile post 162 and 165 in Franklin County. There were numerous reports of wind damage around Franklin County. Trees were blown down onto cars and houses. Another semi-tractor trailer was blown off the highway just east of Perry on Highway 44 in Dallas County. Very heavy rain fell with the storms as well. There were numerous reports of urban and small stream flooding. Flash flooding took place in Dallas County, primarily in the Waukee area.

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 23, 11:45 AM CST, 52 minutes earlier.

Area forecast discussion, Jun 23, 11:45 AM CST, 52 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1245 PM CDT TUE JUN 23 2009

...UPDATED 18Z AVIATION AND PUBLIC DISCUSSION...

.SHORT TERM...
STORMS NOW FIRING ALONG OLD OUTFLOW AND MCS THAT ENTERED NW IA LATE
MORNING. INSTABILITY AXIS SUGGESTS SOME SE TURNING DURING THE
AFTERNOON HOURS TODAY. CURRENT WW TO US 30...BUT MAY NEED SOME
ADJUSTMENTS LATER IN AFTERNOON GIVEN CORFIDI VECTORS SHOWING A MORE
SOUTHERLY COMPONENT DURING THE LATE AFTERNOON AND EVENING HOURS.
HAVE RAISED POPS AND THUNDER SOUTH INTO THE AFTERNOON AND EARLY EVE.
HEAT ADV CONTINUES...THOUGH STORMS WILL TAKE SOME OF THE HEAT AWAY
NORTH...LEFT IT GOING FOR THE PRE-ENVIRONMENT WHICH REMAINS QUITE
HOT. /REV

..PREVIOUS SHORT TERM...TODAY
ISOLATED CONVECTION CONTINUES TO PERCOLATE OVER WESTERN IA IN
VICINITY OF BAND OF 850 MB THETA-E ADVECTION AND 100 MB MLCAPES OF
2500 J/KG. THE FORCING AND HIGH INSTABILITIES WILL REMAIN OVER THE
SOUTHWESTERN FORECAST AREA THEREFORE WILL INTRODUCE ISOLATED THUNDER
MENTION. BIGGER CONCERN FOR CONVECTIVE CHANCES IS CURRENT MCS ACROSS
WESTERN NEBRASKA. IF THE MCS GETS ROOTED IN AND BEGINS TO FOLLOW
EASTWARD POINTING CORFIDI VECTORS...IT COULD END UP IN IOWA BY THIS
AFTERNOON. ANOTHER SCENARIO COULD BE A DECAYING MCS OR REMNANT MCV
ARRIVING DURING PEAK HEATING WHEN HIGH INSTABILITY AND LITTLE CIN
REMAINS...REFIRES AND FOLLOWS THE INSTABILITY AXIS RIGHT INTO
CENTRAL IA.  DO FAVOR THUNDER REACHING THE FORECAST AREA BEFORE 00Z
AND GIVEN MULTIPLE SCENARIOS AND TIMEFRAMES THIS COULD HAPPEN...HAVE
INCREASED POPS OVER THE NORTHWEST HALF.

REGARDING HEAT INDEX POTENTIAL. EXPECT A SIMILAR DAY TO MONDAY WITH
HIGHER DEW POINTS OVER THE CENTRAL AND SOUTH WHERE DEW POINTS WILL
BE IN THE LOWER TO MID 70S AND HIGHS IN THE LOWER TO MID 90S. THIS
WILL RESULT IN HEAT INDEX VALUES OF 105 TO 110. FARTHER NORTH...DEW
POINTS REMAIN LOWER AND ARE CURRENTLY IN THE MID TO UPPER 60S.
SOUNDINGS SUGGEST MIXING WILL LIMIT MAX DEW POINTS TO AROUND 70.
ANOTHER FACTOR IS POTENTIAL BLOW OFF CLOUD COVER FROM NEBRASKA
CONVECTION TO LIMIT HIGHS ACROSS PORTIONS OF THE NORTH. CURRENT
FORECAST HEAT INDEX READINGS ARE 100-103 AND BELOW ADVISORY
CRITERIA. DESPITE THIS...WILL MAINTAIN INHERITED ADVISORY SINCE IT
IS ALREADY OUT AND THIS IS THE WARMEST AND MOST HUMID IT HAS BEEN TO
DATE THIS YEAR.

.LONG TERM...TONIGHT THROUGH MONDAY
THE MAIN FOCUS THIS PERIOD WILL BE THE NEAR TERM WITH POTENTIAL FOR
SEVERAL ROUNDS OF HEAVY RAIN AND ISOLD SEVERE WEATHER THROUGH
WEDNESDAY. THE INITIAL CONCERN IS ONE OR MORE THUNDERSTORM COMPLEXES
TONIGHT ACROSS IOWA. THE GFS DRIVES AN OVERNIGHT MCS ACROSS
SOUTHERN MINNESOTA...DESPITE INDICATIONS OF A SOUTHWARD PUSH WITH
THE CORFIDI VECTORS AND INSTABILITY AXIS AT 06Z. CONCEPTUALLY...THE
NAM12 AND LOCAL 3.5KM WRF MAKE MORE SENSE IN DRIVING THE MCS(S)
SOUTH INTO THE HEART OF THE FORECAST AREA WITH ATTENDANT WIND/HAIL
THREAT ALONG WITH VERY HEAVY RAIN. WOULD ALSO THINK THE UPPER RIDGE
WOULD KEEP STORMS FROM MOVING THAT FAR EAST. BASED ON THE NAM/WRF
SOLUTIONS...HAVE MADE SOME SIGNIFICANT UPWARD ADJUSTMENTS IN
POPS...ESPECIALLY TONIGHT AND WEDNESDAY. JUST HOW FAR SOUTH ANY
COMPLEXES DRIVE TONIGHT WILL BE A KEY FACTOR IN HOW WIDESPREAD THE
FLASH FLOOD THREAT IS. INCREASING CIN WITH TIME COULD WEAKEN STORMS
OVERNIGHT AS THEY MOVE INTO SOUTHERN IOWA. FOR NOW HAVE STAYED NEAR
TO SLIGHTLY ABOVE HPC QPF...WHICH KEEPS THE HEAVIEST RAIN NORTH OF
HIGHWAY 30. CURRENT 12 INCH SOIL MOISTURE ANOMALIES ARE HIGHEST OVER
EASTERN AND SOUTHERN PORTIONS OF THE CWA. MATCHING UP SOIL MOISTURE
WITH HEAVIEST RAIN POTENTIAL...THE NORTHEAST COUNTIES WOULD HAVE THE
HIGHEST OVERALL THREAT OF FLASH FLOODING OVERNIGHT. HOWEVER...IF THE
HEAVY RAIN IS SUSTAINED FARTHER S/SE...THE RISK WOULD INCREASE. ON
WEDNESDAY...A BOUNDARY WILL LIKELY STALL OUT ACROSS IOWA FOLLOWED BY
THE ARRIVAL OF ANOTHER SHORT WAVE TROUGH. MORE SEVERE STORMS AND
HEAVY RAIN ARE POSSIBLE...ALTHOUGH THERE IS MUCH LESS CONFIDENCE IN
THE DETAILS. HAVE AGAIN TRENDED POPS UPWARD WEDNESDAY AND WEDNESDAY
NIGHT. FLASH FLOODING EVENTS HAVE BEEN VERY INFREQUENT DURING THE
RECENT WET PERIOD...BUT PORTIONS OF THE CWA WILL LIKELY NOT BE AS
FORTUNATE THROUGH WEDNESDAY.

THE HEAT ADVISORY MAY HAVE TO BE EXTENDED OVERNIGHT TONIGHT INTO
WEDNESDAY...MAINLY SOUTH OF INTERSTATE 80...WHERE CURRENT
TEMP/DEWPOINTS PUSH HEAT INDEX VALUES NEAR TO SLIGHTLY ABOVE 105
DEGREES WEDNESDAY AFTERNOON. NO CHANGES MADE TO THE EXTENDED
PERIOD...FRIDAY THROUGH MONDAY.

&&

.AVIATION...23/18Z
LINE OF CONVECTION NOW MOVING ACROSS THE NORTHERN AREAS AND WILL
IMPACT KFOD...KMCW...AND KALO FOR THE AFTERNOON HOURS. HAVE ADDED
VRB25G40KT GUSTS WITH TSRA EXPECTED AS THE LINE PASSES EAST. PSBL TO
SEE 50KT GUSTS WITH SOME OF THE STRONGER STORMS. FARTHER
SOUTH...STORMS NOT AS LIKELY EARLY ON BUT CONTINUED CHANCES FOR SOME
THUNDER AT KDSM DURING THE 20-22Z PERIOD THIS AFTERNOON. OVERNIGHT
TNT ANOTHER CHANCE FOR STORMS AND WILL LEAVE FOR EVENING SHIFT TO
PIN DOWN MOST FAVORED AREAS...THOUGH NORTHERN AND CENTRAL AREAS LOOK
TO BE MOST FAVORABLE AT PRESENT./REV

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT TUESDAY ALONG AND SOUTH OF I-80 HEAT
ADVISORY NOON-7 PM CDT TODAY NORTH OF I-80.

&&

SHORT TERM...DONAVON/REV
AVIATION...COGIL
LONG TERM...KINNEY

Hazardous weather outlook, Jun 23, 3:42 AM CST, 8 hours 55 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
442 AM CDT TUE JUN 23 2009

IAZ057>062-070>075-081>086-092>097-241100-
AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-POWESHIEK-CASS-ADAIR-MADISON-
WARREN-MARION-MAHASKA-ADAMS-UNION-CLARKE-LUCAS-MONROE-WAPELLO-
TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS-
442 AM CDT TUE JUN 23 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
SOUTHERN IOWA....SOUTH OF HIGHWAY 30.

.DAY ONE...TODAY AND TONIGHT

VERY HOT AND HUMID CONDITIONS WILL PERSIST TODAY. A HEAT ADVISORY
IS IN EFFECT FOR THE AREA THROUGH THIS AFTERNOON. PLEASE REFER TO
THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES FOR
FURTHER DETAILS.

ISOLATED NON SEVERE THUNDERSTORMS WILL CONTINUE THIS
MORNING...MAINLY WEST OF INTERSTATE 35. ADDITIONAL STORMS ARE
POSSIBLE TONIGHT. A FEW STORMS COULD BE SEVERE...WITH ISOLATED 60
MPH WIND GUSTS THE MAIN THREAT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

HOT AND HUMID CONDITIONS WILL PERSIST WEDNESDAY...WITH AFTERNOON
HEAT INDEX VALUES AROUND 105 DEGREES.

MORE THUNDERSTORMS ARE EXPECTED WEDNESDAY INTO THURSDAY MORNING.
ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINFALL ARE POSSIBLE...ESPECIALLY
WEDNESDAY NIGHT. ADDITIONAL THUNDERSTORM CHANCES ARRIVE FRIDAY
NIGHT INTO THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED AT VARIOUS TIMES TONIGHT
THROUGH WEDNESDAY NIGHT.

IAZ004>007-015>017-023>028-033>039-044>050-241100-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE-
BOONE-STORY-MARSHALL-TAMA-
442 AM CDT TUE JUN 23 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
NORTHERN IOWA...ALONG AND NORTH OF HIGHWAY 30.

.DAY ONE...TODAY AND TONIGHT

VERY HOT AND HUMID CONDITIONS ARE EXPECTED THIS AFTERNOON. A HEAT
ADVISORY IS IN EFFECT FOR THE AREA THIS AFTERNOON. PLEASE REFER
TO THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES
FOR FURTHER DETAILS.

ISOLATED NON SEVERE THUNDERSTORMS ARE POSSIBLE THIS MORNING...MAINLY
WEST OF INTERSTATE 35. ADDITIONAL STORMS ARE EXPECTED LATE THIS AFTERNOON
AND TONIGHT. A FEW STORMS COULD BE SEVERE...WITH ISOLATED 60 MPH
WIND GUSTS THE MAIN THREAT. LOCALLY HEAVY RAINFALL IS EXPECTED...AND
ISOLATED FLASH FLOODING CANNOT BE RULED OUT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

MORE THUNDERSTORMS ARE EXPECTED WEDNESDAY INTO THURSDAY MORNING.
ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINFALL ARE POSSIBLE...ESPECIALLY
WEDNESDAY NIGHT. ADDITIONAL THUNDERSTORM CHANCES ARRIVE FRIDAY
NIGHT INTO THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED AT VARIOUS TIMES TONIGHT
THROUGH WEDNESDAY NIGHT.

KINNEY

The radar

The Minneapolis radar (KMPX), 182 km away, was scanning. The volume nearest the first event began at 18:37 UTC.

Open the radar archive at this moment

Event by event

72 thunderstorm wind, 12 hail, 7 heavy rain, 3 flash flood, 1 high wind. Local standard time, as filed.

Hail, Kossuth

When: June 23, 12:37 PM CST
Where: Kossuth County, 3.26 mi NW of Seneca
Measured: 0.88 in hail
Crop damage: $5,000
Reported by: Law Enforcement
Coordinates: 43.330, -94.430

Thunderstorm Wind, Humboldt

When: June 23, 12:50 PM CST
Where: Humboldt County, Bode
Measured: 57 kt (66 mph) estimated gust
Crop damage: $5,000
Reported by: Newspaper
Coordinates: 42.870, -94.280

Garage building was blown down in the town of Bode.

Thunderstorm Wind, Humboldt

When: June 23, 1:00 PM CST
Where: Humboldt County, 0.51 mi W of Bode
Measured: 54 kt (62 mph) estimated gust
Property damage: $3,000
Reported by: Emergency Manager
Coordinates: 42.870, -94.290

A garage was damaged in the city of Bode.

Thunderstorm Wind, Humboldt

When: June 23, 1:00 PM CST
Where: Humboldt County, Livermore
Measured: 50 kt (58 mph) estimated gust
Property damage: $3,000
Reported by: Emergency Manager
Coordinates: 42.870, -94.180

Thunderstorm Wind, Humboldt

When: June 23, 1:00 PM CST
Where: Humboldt County, Livermore
Measured: 61 kt (70 mph) estimated gust
Property damage: $20,000
Crop damage: $5,000
Reported by: Trained Spotter
Coordinates: 42.870, -94.180

There were numerous reports of tree damage in town, and a grill was blown over. The doors were blown out at the grain elevator.

Thunderstorm Wind, Greene

When: June 23, 1:05 PM CST
Where: Greene County, 1.47 mi NNE of Churdan
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Crop damage: $5,000
Reported by: Amateur Radio
Coordinates: 42.190, -94.470

Thunderstorm Wind, Kossuth

When: June 23, 1:15 PM CST
Where: Kossuth County, 2.05 mi NW of Lu Verne
Measured: 61 kt (70 mph) estimated gust
Property damage: $75,000
Crop damage: $50,000
Reported by: Emergency Manager
Coordinates: 42.940, -94.110

Kossuth County EM reports a swath of wind damage from Lu Verne extending 6 miles west and 4 miles north. Trees and power lines were downed and crops were flattened.

Thunderstorm Wind, Webster

When: June 23, 1:15 PM CST
Where: Webster County, 0.69 mi N of Ft Dodge
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: Trained Spotter
Coordinates: 42.510, -94.180

Large tree limbs were blown down.

Thunderstorm Wind, Wright

When: June 23, 1:38 PM CST
Where: Wright County, 1.71 mi NW of Clarion Arpt
Measured: 60 kt (69 mph) measured gust
Property damage: $2,000
Reported by: AWOS
Coordinates: 42.750, -93.770

Thunderstorm Wind, Franklin

When: June 23, 1:45 PM CST
Where: Franklin County, 0.86 mi SW of Alexander
Measured: 61 kt (70 mph) estimated gust
Property damage: $2,000
Reported by: SHAVE Project
Coordinates: 42.790, -93.480

Shingles were torn off a new roof.

Thunderstorm Wind, Wright

When: June 23, 1:45 PM CST
Where: Wright County, 3.49 mi N of Rowan
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: SHAVE Project
Coordinates: 42.780, -93.540

An old pine tree was snapped 10 feet up from the base.

Thunderstorm Wind, Winnebago

When: June 23, 1:49 PM CST
Where: Winnebago County, Forest City
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Newspaper
Coordinates: 43.270, -93.650

Numerous trees were blown over.

Thunderstorm Wind, Wright

When: June 23, 1:54 PM CST
Where: Wright County, 0.51 mi W of Eagle Grove
Measured: 50 kt (58 mph) measured gust
Property damage: $2,000
Reported by: Mesonet
Coordinates: 42.670, -93.910

Schoolnet site.

Thunderstorm Wind, Cerro Gordo

When: June 23, 1:55 PM CST
Where: Cerro Gordo County, Meservey
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 42.920, -93.480

Numerous branches were reported down up to 6 inches in diameter.

Thunderstorm Wind, Franklin

When: June 23, 1:56 PM CST
Where: Franklin County, 1.47 mi SSW of Alexander
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: SHAVE Project
Coordinates: 42.780, -93.480

Trees were reported snapped at the base.

Thunderstorm Wind, Franklin

When: June 23, 2:00 PM CST
Where: Franklin County, 2.81 mi S of Alexander
Measured: 61 kt (70 mph) estimated gust
Property damage: $15,000
Crop damage: $5,000
Reported by: SHAVE Project
Coordinates: 42.760, -93.480

Three to 4 foot diameter Cottonwood trees were snapped. Roof damage was reported to a house, along with damage to the garage door.

Hail, Wright

When: June 23, 2:00 PM CST
Where: Wright County, 3.34 mi ESE of Belmond
Measured: 1.75 in hail
Property damage: $5,000
Crop damage: $10,000
Reported by: SHAVE Project
Coordinates: 42.830, -93.540

High Wind, Hamilton

When: June 23, 2:00 PM CST to 3:00 PM CST
Where: Hamilton forecast zone
Measured: 50 kt (58 mph) measured gust
Property damage: $10,000
Reported by: Mesonet
Coordinates: 42.384, -93.707 (the zone’s center; the record gives no point)

Thunderstorm Wind, Franklin

When: June 23, 2:05 PM CST
Where: Franklin County, 2.81 mi S of Chapin
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: Storm Chaser
Coordinates: 42.830, -93.220

Extensive tree damage was reported near Chapin.

Thunderstorm Wind, Greene

When: June 23, 2:15 PM CST
Where: Greene County, 101.88 mi E of Angus
Measured: 57 kt (66 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.930, -92.200

Large tree branches were reported down.

Thunderstorm Wind, Franklin

When: June 23, 2:17 PM CST
Where: Franklin County, 2.46 mi NW of Geneva
Measured: 54 kt (62 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 42.700, -93.170

Shingles were blown off houses, and power poles were leaning. Up to 8 inch diameter tree branches were blown down.

Thunderstorm Wind, Franklin

When: June 23, 2:18 PM CST
Where: Franklin County, 3.77 mi SSE of Chapin
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 42.820, -93.200

Hail, Boone

When: June 23, 2:19 PM CST
Where: Boone County, 2.81 mi N of Berkley
Measured: 0.88 in hail
Crop damage: $10,000
Reported by: Law Enforcement
Coordinates: 41.990, -94.110

Boone County law reported hail to nickel size with 45 to 50 MPH winds.

Hail, Boone

When: June 23, 2:26 PM CST
Where: Boone County, 0.51 mi E of Berkley
Measured: 1 in hail
Property damage: $3,000
Crop damage: $10,000
Reported by: Emergency Manager
Coordinates: 41.950, -94.110

Hail, Boone

When: June 23, 2:26 PM CST
Where: Boone County, 3.08 mi E of Berkley
Measured: 0.88 in hail
Crop damage: $5,000
Reported by: Storm Chaser
Coordinates: 41.950, -94.060

Thunderstorm Wind, Boone

When: June 23, 2:26 PM CST
Where: Boone County, 3.08 mi E of Berkley
Measured: 61 kt (70 mph) estimated gust
Property damage: $5,000
Crop damage: $10,000
Reported by: Storm Chaser
Coordinates: 41.950, -94.060

Thunderstorm Wind, Franklin

When: June 23, 2:26 PM CST
Where: Franklin County, 1.91 mi WNW of Coulter
Measured: 61 kt (70 mph) estimated gust
Property damage: $30,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 42.739, -93.405

Two semis were blown off of Interstate 35.

Thunderstorm Wind, Hardin

When: June 23, 2:30 PM CST
Where: Hardin County, Ackley
Measured: 57 kt (66 mph) estimated gust
Property damage: $15,000
Reported by: Trained Spotter
Coordinates: 42.550, -93.050

Large trees were down throughout town making streets impassible. Some trees were on houses.

Thunderstorm Wind, Franklin

When: June 23, 2:34 PM CST
Where: Franklin County, 1.89 mi NNW of Ackley to 0.37 mi NW of Ackley
Measured: 61 kt (70 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 42.574, -93.067

Tree damage north of Ackley and in Ackley. Two miles north of Ackley trees branches were down over powerlines, and the powerlines were on fire.

Thunderstorm Wind, Hardin

When: June 23, 2:34 PM CST
Where: Hardin County, Iowa Falls Muni Arpt
Measured: 54 kt (62 mph) measured gust
Property damage: $5,000
Reported by: AWOS
Coordinates: 42.470, -93.270

Thunderstorm Wind, Franklin

When: June 23, 2:35 PM CST
Where: Franklin County, 0.69 mi S of Hampton
Measured: 61 kt (70 mph) estimated gust
Property damage: $10,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 42.740, -93.200

Tree damage was reported and corn was flattened on the west edge of Hampton near the fairgrounds.

Thunderstorm Wind, Dallas

When: June 23, 2:45 PM CST
Where: Dallas County, 1.24 mi NE of Perry
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.840, -94.100

Semi was blown off the road on the east side of Perry.

Thunderstorm Wind, Story

When: June 23, 2:45 PM CST
Where: Story County, 1.03 mi E of Kelley
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: Law Enforcement
Coordinates: 41.950, -93.660

An 18 inch diameter tree was snapped and blown down.

Thunderstorm Wind, Hardin

When: June 23, 2:45 PM CST
Where: Hardin County, 0.86 mi SE of Union
Measured: 61 kt (70 mph) estimated gust
Property damage: $5,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 42.240, -93.060

A pine tree was uprooted and 2 foot tall grass was flattened by estimated 70 MPH winds.

Thunderstorm Wind, Boone

When: June 23, 2:45 PM CST
Where: Boone County, 5.74 mi SSE of Berkley
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: SHAVE Project
Coordinates: 41.870, -94.090

Eight to 10 inch tree was snapped.

Thunderstorm Wind, Boone

When: June 23, 2:45 PM CST
Where: Boone County, 5.08 mi SSE of Berkley
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: SHAVE Project
Coordinates: 41.880, -94.090

A large tree was down with multiple small branches reported down too.

Hail, Dallas

When: June 23, 2:45 PM CST
Where: Dallas County, 2.07 mi SE of Bouton
Measured: 0.88 in hail
Property damage: $1,000
Crop damage: $5,000
Reported by: SHAVE Project
Coordinates: 41.830, -93.990

Hail, Dallas

When: June 23, 2:48 PM CST
Where: Dallas County, 2.14 mi SSW of Bouton
Measured: 1.5 in hail
Property damage: $20,000
Crop damage: $10,000
Reported by: SHAVE Project
Coordinates: 41.820, -94.030

Thunderstorm Wind, Hardin

When: June 23, 2:55 PM CST
Where: Hardin County, 1.47 mi SSW of Cleves
Measured: 59 kt (68 mph) measured gust
Property damage: $2,000
Reported by: Mesonet
Coordinates: 42.450, -93.060

Thunderstorm Wind, Dallas

When: June 23, 2:55 PM CST
Where: Dallas County, 1.24 mi NE of Minburn
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: SHAVE Project
Coordinates: 41.780, -94.010

Twelve inch diameter tree branches blown down.

Thunderstorm Wind, Dallas

When: June 23, 3:03 PM CST
Where: Dallas County, 1.24 mi NW of Dallas Center
Measured: 75 kt (86 mph) estimated gust
Property damage: $50,000
Crop damage: $5,000
Reported by: SHAVE Project
Coordinates: 41.690, -93.990

A grain bin was shifted and the roof was torn off. Shingle and siding damage was done to a house. Trees were snapped.

Thunderstorm Wind, Dallas

When: June 23, 3:05 PM CST
Where: Dallas County, 2.48 mi SE of Minburn
Measured: 61 kt (70 mph) estimated gust
Property damage: $5,000
Crop damage: $10,000
Reported by: SHAVE Project
Coordinates: 41.750, -93.990

A few small trees were blown over and the corn was blown down.

Thunderstorm Wind, Dallas

When: June 23, 3:05 PM CST
Where: Dallas County, 0.69 mi N of Dallas Center Arpt
Measured: 75 kt (86 mph) estimated gust
Property damage: $75,000
Crop damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.690, -94.020

Straight line winds blew down two hangars at a private air strip.

Thunderstorm Wind, Dallas

When: June 23, 3:06 PM CST
Where: Dallas County, 2.76 mi N of Dallas Center
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: SHAVE Project
Coordinates: 41.720, -93.970

Six to 8 inch diameter branches were blown down.

Thunderstorm Wind, Dallas

When: June 23, 3:06 PM CST
Where: Dallas County, 0.69 mi N of Dallas Center
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: SHAVE Project
Coordinates: 41.690, -93.970

A two foot diameter Oak tree was uprooted and landed on the neighbor's house. Large branches were also reported down.

Hail, Dallas

When: June 23, 3:06 PM CST
Where: Dallas County, 2.76 mi N of Dallas Center
Measured: 1 in hail
Property damage: $5,000
Crop damage: $10,000
Reported by: SHAVE Project
Coordinates: 41.720, -93.970

Thunderstorm Wind, Dallas

When: June 23, 3:08 PM CST
Where: Dallas County, 0.52 mi E of Dallas Center
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.680, -93.960

Thunderstorm Wind, Butler

When: June 23, 3:10 PM CST
Where: Butler County, 2.76 mi S of Clarksville
Measured: 61 kt (70 mph) measured gust
Property damage: $10,000
Reported by: County Official
Coordinates: 42.740, -92.670

Thunderstorm Wind, Marshall

When: June 23, 3:10 PM CST
Where: Marshall County, 0.86 mi SE of Marshalltown
Measured: 52 kt (60 mph) estimated gust
Property damage: $2,000
Reported by: Trained Spotter
Coordinates: 42.040, -92.910

Six inch tree limbs were blown down.

Thunderstorm Wind, Dallas

When: June 23, 3:12 PM CST
Where: Dallas County, 1.24 mi NW of Dallas Center
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Reported by: Fire Department/Rescue
Coordinates: 41.690, -93.990

Tree damage was reported in Dallas Center. Sign damage was reported along with powerlines down along Highway 44 west of Dallas Center to Highway 169.

Thunderstorm Wind, Marshall

When: June 23, 3:12 PM CST
Where: Marshall County, 0.69 mi S of Marshalltown Arpt
Measured: 50 kt (58 mph) measured gust
Property damage: $2,000
Reported by: ASOS
Coordinates: 42.110, -92.920

Hail, Dallas

When: June 23, 3:18 PM CST
Where: Dallas County, 0.52 mi E of Panther
Measured: 0.75 in hail
Crop damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.680, -94.090

Hail, Dallas

When: June 23, 3:18 PM CST
Where: Dallas County, 2.48 mi SE of Panther
Measured: 0.88 in hail
Property damage: $1,000
Crop damage: $10,000
Reported by: SHAVE Project
Coordinates: 41.660, -94.060

Thunderstorm Wind, Dallas

When: June 23, 3:22 PM CST
Where: Dallas County, 1.48 mi NNW of Dallas Center
Measured: 65 kt (75 mph) estimated gust
Property damage: $50,000
Crop damage: $15,000
Reported by: Emergency Manager
Coordinates: 41.700, -93.980

Dallas County EM reports roof ripped off farm buildings and corn blown over.

Thunderstorm Wind, Polk

When: June 23, 3:22 PM CST
Where: Polk County, Commerce
Measured: 52 kt (60 mph) measured gust
Property damage: $3,000
Reported by: Mesonet
Coordinates: 41.530, -93.770

Thunderstorm Wind, Dallas

When: June 23, 3:22 PM CST
Where: Dallas County, 1.24 mi NW of Dallas Center
Measured: 61 kt (70 mph) estimated gust
Property damage: $15,000
Crop damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.690, -93.990

Trees and sheds blown down.

Thunderstorm Wind, Black Hawk

When: June 23, 3:23 PM CST
Where: Black Hawk County, 1.72 mi NE of Cedar Falls Isley Ar
Measured: 61 kt (70 mph) estimated gust
Property damage: $15,000
Reported by: Amateur Radio
Coordinates: 42.540, -92.500

Trees at least a foot in diameter were snapped off at the base. Numerous other trees and signs were down along Highway 57 just west of Cedar Falls. Occurred on the back side of the storm.

Thunderstorm Wind, Bremer

When: June 23, 3:27 PM CST
Where: Bremer County, 1.67 mi WSW of Janesville
Measured: 56 kt (64 mph) estimated gust
Property damage: $25,000
Reported by: Trained Spotter
Coordinates: 42.640, -92.500

Thunderstorm Wind, Bremer

When: June 23, 3:30 PM CST
Where: Bremer County, 0.86 mi SE of Janesville
Measured: 57 kt (66 mph) estimated gust
Property damage: $25,000
Reported by: Trained Spotter
Coordinates: 42.640, -92.460

Tree branches of 18 inch diameter were broken. A tree fell on a house. Powerlines were reported down.

Thunderstorm Wind, Bremer

When: June 23, 3:30 PM CST
Where: Bremer County, 0.86 mi NW of Tripoli
Measured: 61 kt (70 mph) estimated gust
Property damage: $40,000
Crop damage: $10,000
Reported by: Emergency Manager
Coordinates: 42.810, -92.260

Large trees were downed with 2 barns destroyed.

Thunderstorm Wind, Polk

When: June 23, 3:30 PM CST
Where: Polk County, 1.24 mi SE of Ashawa
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Public
Coordinates: 41.570, -93.750

Thunderstorm Wind, Polk

When: June 23, 3:32 PM CST
Where: Polk County, 1.73 mi NE of Commerce
Measured: 54 kt (62 mph) measured gust
Property damage: $3,000
Reported by: Mesonet
Coordinates: 41.550, -93.750

Thunderstorm Wind, Black Hawk

When: June 23, 3:35 PM CST
Where: Black Hawk County, 0.6 mi W of Cedar Falls
Measured: 57 kt (66 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 42.522, -92.462

Power poles were blown down at 19th and Summit.

Thunderstorm Wind, Black Hawk

When: June 23, 3:35 PM CST
Where: Black Hawk County, 0.98 mi N of Cedar Falls
Measured: 57 kt (66 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 42.534, -92.451

Power pole was blown down.

Thunderstorm Wind, Bremer

When: June 23, 3:35 PM CST
Where: Bremer County, 0.86 mi NW of Tripoli
Measured: 57 kt (66 mph) estimated gust
Property damage: $25,000
Reported by: Emergency Manager
Coordinates: 42.810, -92.260

Trees and powerlines were blown down throughout the area.

Thunderstorm Wind, Black Hawk

When: June 23, 3:35 PM CST
Where: Black Hawk County, 0.51 mi W of Cedar Falls
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Emergency Manager
Coordinates: 42.520, -92.460

Thunderstorm Wind, Dallas

When: June 23, 3:41 PM CST
Where: Dallas County, 0.81 mi NNE of De Soto
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.541, -94.013

Reports of 60 to 65 MPH winds and nickel hail at the intersection of Highway 169 and Interstate 80.

Thunderstorm Wind, Black Hawk

When: June 23, 3:45 PM CST
Where: Black Hawk County, 0.51 mi E of Dunkerton
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Broadcast Media
Coordinates: 42.570, -92.160

Tree branches with the diameter of 2-liter pop bottles were blown down. Received from KWWL TV.

Thunderstorm Wind, Dallas

When: June 23, 3:45 PM CST
Where: Dallas County, 1.7 mi WSW of Hadden Hill
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 41.610, -93.860

Trees several inches in diameter were blown down.

Thunderstorm Wind, Adair

When: June 23, 3:45 PM CST
Where: Adair County, 6.93 mi N of Rosserdale
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 41.500, -94.410

Thunderstorm Wind, Cass

When: June 23, 3:48 PM CST
Where: Cass County, 0.52 mi E of Atlantic
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 41.400, -95.010

Winds of 60 MPH were reported with trees and powerlines down in town.

Heavy Rain, Adair

When: June 23, 3:56 PM CST to 4:56 PM CST
Where: Adair County, 7.58 mi NNE of Howe
Reported by: Emergency Manager
Coordinates: 41.500, -94.320

Hail, Dallas

When: June 23, 3:58 PM CST
Where: Dallas County, 0.86 mi SE of De Soto
Measured: 1 in hail
Property damage: $5,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.520, -94.010

Thunderstorm Wind, Warren

When: June 23, 4:00 PM CST
Where: Warren County, 3.08 mi S of Indianola Arpt
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Crop damage: $10,000
Reported by: Law Enforcement
Coordinates: 41.256, -93.578

Dime size hail and 60 MPH winds were reported.

Hail, Madison

When: June 23, 4:00 PM CST
Where: Madison County, 7.24 mi E of Earlham
Measured: 0.88 in hail
Property damage: $1,000
Crop damage: $10,000
Reported by: SHAVE Project
Coordinates: 41.500, -93.990

Thunderstorm Wind, Adair

When: June 23, 4:00 PM CST
Where: Adair County, 0.86 mi SW of Adair
Measured: 61 kt (70 mph) estimated gust
Property damage: $5,000
Crop damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.490, -94.660

Torrential wind driven rain with near zero visibility along with pea size hail was reported.

Heavy Rain, Polk

When: June 23, 4:00 PM CST to 4:25 PM CST
Where: Polk County, 2.49 mi NW of Ashawa
Reported by: Broadcast Media
Coordinates: 41.600, -93.810

Thunderstorm Wind, Warren

When: June 23, 4:05 PM CST
Where: Warren County, Carlisle
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Newspaper
Coordinates: 41.500, -93.500

High winds caused tree damage in Carlisle.

Heavy Rain, Polk

When: June 23, 4:07 PM CST to 5:07 PM CST
Where: Polk County, 1.24 mi NW of Clover Hills
Reported by: Broadcast Media
Coordinates: 41.610, -93.770

Minor street flooding.

Thunderstorm Wind, Cass

When: June 23, 4:17 PM CST
Where: Cass County, 0.52 mi E of Massena
Measured: 56 kt (64 mph) estimated gust
Property damage: $15,000
Reported by: Public
Coordinates: 41.250, -94.770

Widespread tree damage was reported in Massena.

Thunderstorm Wind, Cass

When: June 23, 4:21 PM CST
Where: Cass County, 2.6 mi E of Massena
Measured: 57 kt (66 mph) estimated gust
Property damage: $10,000
Crop damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.250, -94.730

Twenty four inch diameter trees were down.

Thunderstorm Wind, Mahaska

When: June 23, 4:25 PM CST
Where: Mahaska County, 0.86 mi SE of Oskaloosa
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 41.290, -92.640

Heavy Rain, Polk

When: June 23, 4:32 PM CST to 5:32 PM CST
Where: Polk County, 0.52 mi W of Rider
Reported by: NWS Employee
Coordinates: 41.670, -93.790

Minor street flooding and creek rising rapidly.

Heavy Rain, Polk

When: June 23, 4:45 PM CST to 5:45 PM CST
Where: Polk County, 0.69 mi S of Lovington
Reported by: Trained Spotter
Coordinates: 41.640, -93.700

Minor street flooding.

Heavy Rain, Polk

When: June 23, 4:50 PM CST to 5:50 PM CST
Where: Polk County, 1.47 mi SSW of Oralabor
Reported by: NWS Employee
Coordinates: 41.710, -93.640

Heavy Rain, Polk

When: June 23, 4:50 PM CST to 5:50 PM CST
Where: Polk County, 1.03 mi W of Lovington
Reported by: NWS Employee
Coordinates: 41.650, -93.720

Thunderstorm Wind, Wapello

When: June 23, 4:56 PM CST
Where: Wapello County, 1.71 mi WSW of Ottumwa
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Trained Spotter
Coordinates: 41.010, -92.430

Tree damage was reported in town, and one light pole was blown down.

Thunderstorm Wind, Wapello

When: June 23, 4:56 PM CST
Where: Wapello County, 1.04 mi W of Ottumwa
Measured: 70 kt (81 mph) estimated gust
Property damage: $15,000
Reported by: Trained Spotter
Coordinates: 41.020, -92.420

Thunderstorm Wind, Madison

When: June 23, 5:00 PM CST
Where: Madison County, 0.69 mi N of Winterset
Measured: 54 kt (62 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.340, -94.020

Large trees and powerlines were reported down.

Flash Flood, Dallas

When: June 23, 5:07 PM CST to 10:30 PM CST
Where: Dallas County, 1.7 mi WSW of Hadden Hill to 1.94 mi ESE of Waukee
Cause: Heavy Rain
Property damage: $20,000
Reported by: Broadcast Media
Coordinates: 41.610, -93.860

Widespread street flooding in the town of Waukee.

Thunderstorm Wind, Wapello

When: June 23, 5:08 PM CST
Where: Wapello County, 1.71 mi WSW of Ottumwa
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 41.010, -92.430

Flash Flood, Dallas

When: June 23, 5:12 PM CST to 10:30 PM CST
Where: Dallas County, 1.78 mi SE of Waukee to 2.01 mi SE of Waukee
Cause: Heavy Rain
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.603, -93.874

Sugar Creek was flooding and continued to rise rapidly in Waukee near Centennial Park.

Thunderstorm Wind, Union

When: June 23, 5:20 PM CST
Where: Union County, Creston
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Newspaper
Coordinates: 41.070, -94.370

Numerous branches broken off by high winds.

Flash Flood, Dallas

When: June 23, 5:25 PM CST to 10:30 PM CST
Where: Dallas County, 0.69 mi S of Hadden Hill to 0.85 mi S of Hadden Hill
Cause: Heavy Rain
Property damage: $10,000
Reported by: Broadcast Media
Coordinates: 41.610, -93.830

Water was 9 to 12 inches deep on Wildwood Ave just west of 156th St. Water depth was 6 inches or more at the intersection of 156th St. and Wildwood Ave.

Thunderstorm Wind, Clarke

When: June 23, 5:26 PM CST
Where: Clarke County, 1.25 mi WSW of Osceola
Measured: 50 kt (58 mph) measured gust
Reported by: Mesonet
Coordinates: 41.020, -93.800

Measured by a state RWIS site.

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
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.
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.
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.

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

The same day elsewhere

Every storm in Iowa in 2009 Every state in 2009 This day in weather history Warnings in Iowa, June 2009

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: 167058, 172364, 167068, 167069, 167101, 167102, 167064, 167103, 167059, 167082, 167083, 172379, 167060, 167030, 167084, 167085, 167093, 167114, 167034, 167104, 167031, 167032, 167020, 167021, 167022, 167023, 167033, 167041, 167042, 167061, 167035, 167036, 167066, 167080, 167086, 167087, 167096, 167097, 167065, 167088, and more.