Tornadoes · United States · Iowa · 2006

F0 tornado, Van Horne, Iowa, April 13, 2006

This F0 tornado ran 4.8 miles across Benton County on April 13, 2006, touching down at 7:50 PM CDT and reaching 150 yards wide. It killed nobody, and did $10,000 of property damage.

The rating scale

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

  1. F040 to 72 mphthis tornado

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 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.

  4. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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.

  7. 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
F0
Date
April 13, 2006
Touchdown
7:50 PM CDT (00:50 UTC)
Path length
4.8 miles (7.7 km)
Path width
150 yards (137 m)
Deaths
0
Injuries
0
Property damage
$10,000
County
Benton County
Touchdown point
41.980, -92.050
Lift-off point
41.970, -91.980
Record number
353

What the Weather Service recorded

Tornado began 3 miles southeast of Van Horne at 1850 CST and continued east along county road W14 and dissipated south of Newhall at 1858 CST. The Newhall fire department observed the tornado crossing highway 287 south of town at 1857 CST. Four power poles were snapped and fences were damaged.

Rated high F0

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

The warnings

5 minutes of warning. NWS DVN issued a tornado warning for this county at 00:45 UTC, 5 minutes before the tornado touched down, in force until 01:30 UTC.

The county was under a severe thunderstorm watch, issued at 22:33 UTC and running to 03:41 UTC.

Issued (UTC)ExpiredProductOffice
22:33 UTC03:41 UTCSevere Thunderstorm WatchDVN
23:50 UTC00:45 UTCSevere Thunderstorm WarningDVN
00:45 UTC01:30 UTCTornado WarningDVN
01:07 UTC02:00 UTCSevere Thunderstorm WarningDVN
01:53 UTC02:45 UTCSevere Thunderstorm WarningDVN

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:58 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Davenport, (KDVN), 00:00Z

0.8 hours before the tornado, 132 km from the path. April 14, 2006.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2006-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 774 joules per kilogram, CIN -72, lifted condensation level 2028 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Davenport, at 00:00Z on 2006-04-14The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 122 square meters per square second, 0 to 6 km bulk shear 59 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
774 J/kg
Mixed-layer CIN
-72 J/kg
Surface CAPE
736 J/kg
Mixed-layer LCL
2028 m above ground
0-6 km bulk shear
59 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
250 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.6
0-3 km lapse rate
7.8 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 12:00Z

11.2 hours after it, 132 km from the path. April 14, 2006.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2006-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 755 joules per kilogram, CIN -276, lifted condensation level 1868 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Davenport, at 12:00Z on 2006-04-14The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 103 square meters per square second, 0 to 6 km bulk shear 56 knots.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
755 J/kg
Mixed-layer CIN
-276 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1868 m above ground
0-6 km bulk shear
56 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.7
0-3 km lapse rate
4.1 K/km

Open this sounding in Storm Lab

The radar

The Quad Cities radar (KDVN), 126 km away, was scanning. The volume nearest the touchdown began at 00:51 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
23:52 UTCHAIL 1.754 Ssw TraerTama, IAREPORTED BY TRAINED SPOTTER.
00:07 UTCHAIL 12 W GarrisonBenton, IA
00:09 UTCHAIL 1TraerTama, IA
00:10 UTCTORNADO5 Ne ToledoTama, IA
00:14 UTCHAIL 0.88VictorIowa, IA
00:15 UTCHAIL 1.75TraerTama, IA
00:17 UTCHAIL 2.54 E TraerTama, IA
00:25 UTCHAIL 110 S WaterlooBlack Hawk, IA
00:28 UTCHAIL 0.88JesupBuchanan, IA
00:29 UTCHAIL 17 Sw VintonBenton, IASPOTTER ALSO REPORTED QUARTER SZE HAIL SOUTH OF GARRISON COVERING THE GROUND.
00:29 UTCHAIL 17 Sw VintonBenton, IASPOTTER ALSO REPORTED QUATER SZE HAIL SOUTH OF GARISONN COVERING THE GROUND.
00:30 UTCHAIL 1.75GarwinTama, IA
00:31 UTCHAIL 1MarengoIowa, IA
00:33 UTCHAIL 1.757 Sw VintonBenton, IA
00:35 UTCHAIL 16 S VintonBenton, IA
00:35 UTCHAIL 1IndependenceBuchanan, IABUCHANAN COUNTY REPORTED ANYTHING FROM PEA TO QUARTER SIZE HAIL ACROSS THE COUNTY.
00:35 UTCHAIL 1.52 N Van HorneBenton, IA
00:36 UTCHAIL 1GarwinTama, IA
00:36 UTCTSTM WND GST 0JesupBuchanan, IA65 MPH WIND GUST
00:37 UTCHAIL 1.75AlburnettLinn, IA
00:38 UTCHAIL 1Cedar RapidsLinn, IA
00:38 UTCHAIL 1.52 N Van HorneBenton, IA
00:40 UTCHAIL 1.25South AmanaIowa, IA
00:42 UTCTORNADOMarionLinn, IAPUBLIC REPORT
00:43 UTCTORNADOMarionLinn, IAPOWER LINES AND TREES DOWN
00:45 UTCHAIL 1Cedar RapidsLinn, IA
00:45 UTCTORNADOIowa CityJohnson, IADOWNTOWN IOWA CITY COURTHOUSE ROOF GONE. LARGE CHURCH ROOF 70 PERCENT GONE. LOTS OF DEBRIS.
00:45 UTCTORNADOIowa CityJohnson, IA*** 2 INJ *** WIDESPREAD DAMAGE TO DOWNTOWN IOWA CITY. 5 TO 10 PEOPLE TRAPPED IN DESTROYED AND COLLAPESED STRUCTURES. AT LEAST 2 CONFIRMED INJURIES. TIME ESTIMATED.
00:45 UTCTORNADOIowa CityJohnson, IA*** 2 INJ *** WIDESPREAD DAMAGE TO DOWNTOWN IOWA CITY. 5 TO 10 PEOPLE TRAPPED IN DESTROYED AND COLLAPSED STRUCTURES. AT LEAST 2 CONFIRMED INJURIES. TIME ESTIMATED.
00:45 UTCTORNADOIowa CityJohnson, IALARGE CONCRETE AND BRICK BUILDING IN DOWNTOWN IOWA CITY TOP TWO FLOORS COLLAPSED.
00:47 UTCHAIL 0.7515 W Cedar RapidsBenton, IA
00:47 UTCHAIL 1Cedar RapidsLinn, IA
00:50 UTCTORNADO2 W WhittierLinn, IADEBRIS CLOUD OBSERVED
00:51 UTCHAIL 1Cedar RapidsLinn, IA
00:52 UTCHAIL 1Cedar RapidsLinn, IANORTHWEST SIDE OF CEDAR RAPIDS.
00:54 UTCTSTM WND DMGMarionLinn, IASPOTTER REPORTED A BARN BLOWN APART AND METAL WRAPED AROUND POLES.
00:54 UTCTSTM WND DMGMarionLinn, IASPOTTER REPORTED A BARN BLOWN APART AND METAL WRAPPED AROUND POLES.
00:55 UTCHAIL 1AtkinsBenton, IA
00:58 UTCHAIL 0.882 N Cedar RapidsLinn, IA
00:58 UTCTORNADONewhallBenton, IA

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2006 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of April 13, 2006

17 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 137:10 PM CDTF0Tama, IA0.130
April 137:40 PM CDTF0Linn, IA1.0200$70,000
April 138:15 PM CDTF1Jones, IA3.78801$100,000
April 138:16 PM CDTF1Johnson, IA3.6350$20,000
April 138:29 PM CDTF2Johnson, IA4.558730$12 million
April 138:38 PM CDTF1Johnson, IA5.1700$70,000
April 138:45 PM CDTF1Muscatine, IA9.444011$120,000
April 138:48 PM CDTF1Muscatine, IA4.8176$80,000
April 139:13 PM CDTF0Muscatine, IA to IL6.4220$15,000
April 139:19 PM CDTF1Johnson, IA0.525$10,000
April 139:29 PM CDTF1Mercer, IL13.0880$20,000
April 139:42 PM CDTF1Scott, IA1.5100$60,000
April 139:57 PM CDTF1Mercer, IL1.5100$50,000
April 1310:07 PM CDTF2Mercer, IL2.050$30,000
April 1310:12 PM CDTF1Mercer, IL0.8200$100,000
April 1312:25 AM CDTF0Logan, IL0.1100
April 1312:27 AM CDTF0Logan, IL3.8125$2.5 million

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.