Tornadoes · United States · Iowa · 2008

EF0 tornado, Stout, Iowa, May 25, 2008

Name: EF0 tornado, Stout, Iowa, May 25, 2008
Start: 2008-05-25T22:07:00.000Z
End: 2008-05-25T22:09:00.000Z
Location: Stout, Iowa

This EF0 tornado ran 1.1 miles across Grundy County on May 25, 2008, touching down at 5:07 PM CDT and reaching 50 yards wide. It killed nobody, and did $1,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating: EF0
Date: May 25, 2008
Touchdown: 5:07 PM CDT (22:07 UTC)
Lifted: 5:09 PM CDT (22:09 UTC)
On the ground: 2 minutes
Path length: 1.1 miles (1.7 km)
Path width: 50 yards (46 m)
Deaths: 0
Injuries: 0
Property damage: $1,000
Crop damage: $1,000
County: Grundy County
Touchdown point: 42.550, -92.682
Lift-off point: 42.551, -92.661
Record number: 0805251607-01

What the Weather Service recorded

A very intense upper low was located over the southwest U.S. and lifted northeast during the weekend of the 24th into the morning of the 26th. The seasons first strong push of deep moisture moved into Iowa on the 25th with surface temperatures warming into the mid 80s and dew points surging into the upper 60s to low 70s. Precipitable water values were near 1.5 inches. The dry slot pushed north across the area the previous night as the warm front lifted north. The primary surface low was located over northern Minnesota. A cold front extended south from the low into northwest Iowa. The airmass became very unstable by the mid afternoon hours. MUCAPE rose to between 4000 and 5000 J/kg. Lifted indices fell to -8 to -11 C. There was a considerable amount of both DCAPE at 1000-1500 J/kg and cape in the -10 to-30 C. layer of the atmoshpere, between 400 and 600 J/kg. The freezing level was around 13,200 feet. The environment was quite sheared with effective shear in the 40 to 50 kt range. LCL values were between 1000 and 1500 meters. The airmass was initially capped. During the late afternoon hours, a small cluster of thunderstorms formed over north central into northeast Iowa. The storms became severe very quickly. Initially, the storms dropped hail up to golf ball in size. One became a strong super cell and produced a major tornado. This cell, in addition to being tornadic, also produced hail of baseball to softball in size and winds in excess of 90 MPH. The tornado track was from approximately 2 miles south of Aplington to Parkersburg, then continued to New Hartford and across northern Black Hawk County. The average path width ranged from 0.6 to 0.7 miles near Parkersburg to just north of New Hartford. The path constricted to near one quarter mile wide east of New Hartford to north of Waterloo. The width then increased to near 1.2 miles wide north of Dunkerton before dissipating near the Black Hawk and Buchanan County line. The tornado was on the ground for approximately 43 miles. In addition to the main tornado, a satellite tornado was observed by storm chasers and one off duty NWS employee. It was located south of the main tornado and was on the ground for a little over a mile in Grundy County. Initial reports indicated 9 fatalities with 7 in Parkersburg (pop 1889) and 2 in New Hartford (pop 637). There were at least 50 injuries, with 4 of those in critical condition. Two of the fatalities occurred a few days after the tornado from injuries sustained in the tornado. The last fatality occurred on 7 Nov. A 61 year old female sustained injuries in the stairwell of her home when a 2 x 4 was thrown through her right side lung. She was hospitalized and died several months later of complications. Significant structural damage occurred across the southern end of Parkersburg and along a path to just north of New Hartford. Numerous structures completely destroyed from Parkersburg to near New Hartford. The tornado continued eastward to just north of the Waterloo and Cedar Falls area. Significant damage also occurred north of Dunkerton where the tornado increased to its greatest path width. This storm also produced substantial straight line wind damage along the southern periphery of the storm just south of the tornado track. News accounts indicated that a receipt from Parkersburg was found around 1915 CST 3 miles north of Prairie du Chien, WI, 109 miles to the northeast. Receipits were also found in Clayton County at Elkader, and full scrapbook pages and photos were found in far northeast Bremer County at Sumner. Preliminary estimates that straight line winds of 90 to 100 MPH occurred with this storm. At 1637 CST, the Waterloo Airport recorded a 93 MPH wind gust. Survey results suggest that straight line wind damage was the cause of the severe damage at the recreational vehicle dealership north of Cedar Falls. At least 627 homes were damaged, including 288 homes destroyed in Parkersburg, 88 in New Hartford, 15 in Hazelton and another 50 in Black Hawk County. In addition, 58 had major damage, 33 had moderate damage, 2 were inaccessible, and 93 damaged but able to be occupied. There were also 21 businesses destroyed. Governor Chet Culver declared both Butler and Black Hawk disaster areas with both given the State Declaration. A Federal Disaster Declaration occurred two days later for both Butler and Black Hawk Counties. The tornado was rated a low end EF5 by a Quick Response Team (QRT) in portions of Parkersburg and north of New Hartford with peak winds estimated at 205 MPH. For historical reference, the last F5 tornado to hit Iowa was on 13 June 1976 in Boone and Story Counties in the town of Jordan, with a 21 mile path length. The last F4 tornado to hit Iowa was in Union, Madison, and Dallas Counties with a 56 mile path length on 8 April 1999. There was one other smaller tornado during the evening. A tornado touched down in Clarke County and was on the ground for a short time southeast of Osceola. After the initial thunderstorm area developed over north central and northeast Iowa, a large complex developed over southeast Nebraska. The two areas of storms filled in to form a squall line by the mid evening hours. The complex over Nebraska then pushed east and northeast along the squall line. A considerable amount of severe weather was generated during the evening as this occurred. Along the squall line, high winds and hail were common with the dominant mode of severe weather being hail of up to golf ball in size. As the MCS out of Nebraska advanced east, a tail extending south from the centroid took on a bow echo configuration and raced east across Iowa at 65 MPH. Very high winds occurred with this feature with numerous locations reporting winds of 65 to 85 MPH. Some of the higher winds included an 85 MPH wind gust in the Winterset area and numerous reports of 75 to 85 MPH winds from Madison, Dallas, Warren and Polk Counties. Lightning struck a house in Ankeny. The house was set on fire by the strike.

Iowa State storm chasers tracked a satellite tornado just south of the main EF-5 tornado. It was located in Grundy County.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

What forecasters said that day

The local office's own words before the tornado touched down, 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 tornado touched down at May 25, 3:38 PM CDT, 1 hour 29 minutes earlier.

Area forecast discussion, May 25, 3:38 PM CDT, 1 hour 29 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
338 PM CDT SUN MAY 25 2008

.DISCUSSION...
FOCUS IS ON DEVELOPING WEATHER. AMPLE MOISTURE IN PLACE AS 70
DEGREE DEW POINTS STREAMING INTO THE CWA. SC LOW IN MN WITH A WARM
FRONT EXTENDING DOWN FM WRN MN INTO ERN IA AND A COLD FRONT FM THE
DAKOTAS INTO ERN NEB WILL SINK SE THROUGH TONIGHT. THE FRONT WILL
SETTLE SOUTH OF IA LATE MONDAY MORNING. ALL MODES OF SEVERE
WEATHER POSSIBLE WITH 4000-5000 J/KG CAPE OVER THE CWA ALONG WITH
50+ KNOTS OF SHEAR. THE CAP IS VIRTUALLY GONE AS WELL AND WITH
THE SUN BREAKING OUT THERE WILL BE RAPID DESTABILIZATION ACROSS
THE CWA WITH STORMS EXPECTED TO RAPIDLY EVOLVE AND BECOME SEVERE.
THE SCENARIO HAS NOT CHANGED IN EVOLVING A COMPLEX OF STORMS OVER
SRN IA TONGIGHT WITH AN INCREASING HEAVY RAIN THREAT AFTER THE
SEVERE EVENT THIS EVENING. AS A RESULT THE FLASH FLOOD WATCH WILL
REMAIN IN PLACE.

THE ACTIVE WEATHER PATTERN CONTINUES AS FLOW BECOMES MORE ZONAL
AND SEVERAL SHORTWAVES PUSH ACROSS THE CWA. NEXT SYSTEM HAS
ALREADY BEEN ADVERTISED FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT
THEN AGAIN MONDAY AND MONDAY NIGHT. AT THIS POINT SEVERE POTENTIAL
LOOKS DECENT FOR THE FRIDAY SYSTEM BUT THERE IS SOME QUESTION ON
TRACK AND TIMING FOR THE MONDAY SYSTEM MAKING IT DIFFICULT TO
DETERMINE ANY SEVERE POTENTIAL AT THIS POINT.

AS FOR TEMPS...A COOL DOWN IS EXPECTED IN THE WAKE OF THIS SYSTEM
WITH HIGHS DIPPING INTO THE 60S AND 70S BUT AS FLOW BECOMES
ZONAL...HIGHS SHOULD BE CLOSER TO NORMAL BY MIDWEEK.

&&

.AVIATION...25/18Z
LOW STRATUS DECK PERSISTED THROUGH MUCH OF THE MORNING HOURS IN
CENTRAL IOWA. BY 18Z...EXPECT ST GO THIN AND DISSIPATE. CDFRONT
MOVG INTO NW IA THIS AFTERNOON SHOULD BE THE FOCUS FOR TSTM
DEVELOPMENT. WL FORECAST 3-4 HOUR TSTM PERIOD IN THE TAF/S AT THE
MOST LIKELY TIMES. IN TIMES WHERE TSTMS ARE STILL PSBL WILL US
VCTS IN TAFS. FRONTAL BOUNDARY SHOULD BE IN SRN IA/NRN MO BY END
OF FCST PD SHIFTING THE TSTM CHANCES SOUTH.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH MONDAY
MORNING FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CARROLL-CASS-
CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-JASPER-LUCAS-
MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-
STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

AVIATION...JOHNSON
SHORT TERM/LONG TERM...FAB

Hazardous weather outlook, May 25, 8:31 AM CDT, 8 hours 36 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
831 AM CDT SUN MAY 25 2008

IAZ044>050-057>062-070>075-081>086-092>097-261345-
CRAWFORD-CARROLL-GREENE-BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-
DALLAS-POLK-JASPER-POWESHIEK-CASS-ADAIR-MADISON-WARREN-MARION-
MAHASKA-ADAMS-UNION-CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-
DECATUR-WAYNE-APPANOOSE-DAVIS-
831 AM CDT SUN MAY 25 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

A FEW ISOLATED NON SEVERE THUNDERSTORMS ARE POSSIBLE DURING THE
DAY. HOWEVER...MORE INTENSE STORMS ARE FORECAST TO DEVELOP LATE
THIS AFTERNOON ACROSS WESTERN IOWA. THESE STORMS MAY BE SEVERE
WITH LARGE HAIL AND DAMAGING WINDS. ISOLATED TORNADOES WILL ALSO
BE POSSIBLE DURING THE LATE AFTERNOON AND EVENING TIME FRAMES. THE
STORMS ARE FORECAST TO CONSOLIDATE OVERNIGHT WITH HEAVY RAINS
ACROSS PORTIONS OF CENTRAL IOWA. SEVERAL INCHES OF NEW RAIN ARE
POSSIBLE LEADING TO FLASH FLOODING. A FLASH FLOOD WATCH HAS BEEN
ISSUED FOR CENTRAL AND SOUTHERN IOWA TONIGHT. PLEASE REFER TO THE
NATIONAL WEATHER SERVICE DES MOINES WEBSITE FOR ADDITIONAL
DETAILS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

ADDITIONAL THREATS FOR THUNDERSTORMS WILL CONTINUE INTO MONDAY AND
EARLY TUESDAY AS WELL AS THURSDAY NIGHT INTO LATE FRIDAY. THE
THREAT FOR SEVERE WEATHER APPEARS LIMITED EARLY IN THE WEEK
ALTHOUGH THE POSSIBILITY OF HEAVY RAINS WILL PERSIST. SEVERE
WEATHER WILL BE POSSIBLE ON THURSDAY NIGHT INTO FRIDAY AS WELL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY LATE THIS AFTERNOON INTO TONIGHT.
SPOTTER MAY ALSO BE NEEDED THURSDAY NIGHT INTO FRIDAY. AN
EMERGENCY MANAGEMENT CONFERENCE CALL HAS BEEN SCHEDULED FOR NOON TODAY.

IAZ004>007-015>017-023>028-033>039-261345-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-
831 AM CDT SUN MAY 25 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

A FEW ISOLATED NON SEVERE THUNDERSTORMS ARE POSSIBLE DURING THE
DAY. HOWEVER...MORE INTENSE STORMS ARE FORECAST TO DEVELOP LATE
THIS AFTERNOON ACROSS WESTERN IOWA. THESE STORMS MAY BE SEVERE
WITH LARGE HAIL AND DAMAGING WINDS. ISOLATED TORNADOES WILL ALSO
BE POSSIBLE DURING THE LATE AFTERNOON AND EVENING TIME FRAMES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS ARE EXPECTED THURSDAY NIGHT INTO FRIDAY. SEVERE
WEATHER IS POSSIBLE WITH THESE STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY LATE THIS AFTERNOON INTO TONIGHT.
SPOTTER MAY ALSO BE NEEDED THURSDAY NIGHT INTO FRIDAY. AN
EMERGENCY MANAGEMENT CONFERENCE CALL HAS BEEN SCHEDULED FOR NOON
TODAY.

In the hours before

Local storm report, May 25, 4:28 PM CDT, 39 minutes before

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Local storm report, May 25, 4:39 PM CDT, 28 minutes before

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Local storm report, May 25, 4:40 PM CDT, 27 minutes before

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The surface observations

Waterloo (ALO), 22 km from the path, in the two hours either side.

Time (UTC)	Temp (°F)	Dew point (°F)	Wind	Gust (kt)	Pressure (mb)	Weather
00:00 UTC

From the Iowa Environmental Mesonet's archive of airport observations.

This ground now

The live radar over the track Every 2008 tornado in Iowa Every tornado in Iowa since 1950 Warnings in force in Iowa now The forecast where you are

The other tornadoes of May 25, 2008

31 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Deaths	Injuries	Damage
May 25	2:57 PM CDT	EF1	Lane, KS	3.0	100
May 25	2:58 PM CDT	EF0	Scott, KS	0.5	50
May 25	3:29 PM CDT	EF0	Hartley, TX	1.7	50
May 25	3:37 PM CDT	EF0	Rush, KS	1.9	150
May 25	3:37 PM CDT	EF0	Hartley, TX	7.7	75
May 25	4:15 PM CDT	EF0	Rush, KS	0.5	25
May 25	4:23 PM CDT	EF0	Trego, KS	1.2	75
May 25	4:35 PM CDT	EF1	Anoka, MN	6.0	100		2	$700,000
May 25	4:47 PM CDT	EF0	Rush, KS	0.5	50
May 25	4:48 PM CDT	EF5	Parkersburg–New Hartford tornado, IA	41.0	2,100	9	70	$100 million
May 25	4:49 PM CDT	EF0	Rush, KS	1.1	100
May 25	4:50 PM CDT	EF0	Rush, KS	0.5	25
May 25	4:53 PM CDT	EF0	Hutchinson, TX	0.5	50
May 25	4:55 PM CDT	EF3	Anoka, MN	6.0	220	1	17	$25 million
May 25	5:10 PM CDT	EF0	Washington, MN	1.0	50
May 25	5:15 PM CDT	EF0	Washington, MN to WI	1.3	50			$300,000
May 25	5:22 PM CDT	EF0	Barton, KS	0.9	75
May 25	5:48 PM CDT	EF0	Cass, MN	4.0	25
May 25	5:55 PM CDT	EF0	Dunn, WI	3.5	50			$200,000
May 25	5:56 PM CDT	EF0	Barton, KS	6.2	75
May 25	6:05 PM CDT	EF3	Buchanan, IA	32.0	1,232		3	$1.1 million
May 25	6:25 PM CDT	EF1	Clarke, IA	6.8	50
May 25	6:35 PM CDT	EF0	Jackson, IL	0.2	20
May 25	6:40 PM CDT	EF1	Buchanan, IA	3.5	100			$50,000
May 25	6:55 PM CDT	EF0	Ellsworth, KS	0.5	50
May 25	7:05 PM CDT	EF0	Saline, KS	0.9	50
May 25	7:19 PM CDT	EF0	Pembina, ND	0.2	25
May 25	7:31 PM CDT	EF1	Delaware, IA	8.5	250			$350,000
May 25	9:00 PM CDT	EF0	Marathon, WI	0.1	10
May 25	11:06 PM CDT	EF1	Iowa, IA	6.2	440			$100,000
May 25	11:38 PM CDT	EF0	Johnson, IA	0.1	100			$10,000

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.