Tornadoes · United States · Iowa · 1990

F1 tornado, Davis County, Iowa, March 13, 1990

This F1 tornado ran 14.0 miles across Davis County on March 13, 1990, touching down at 3:32 PM CST and reaching 23 yards wide. It killed nobody, and did $50,000 to $500,000 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 mph

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

  2. F173 to 112 mphthis tornado

    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
F1
Date
March 13, 1990
Touchdown
3:32 PM CST (21:32 UTC)
Path length
14.0 miles (22.5 km)
Path width
23 yards (21 m)
Deaths
0
Injuries
0
Property damage
$50,000 to $500,000
County
Davis County
Touchdown point
40.650, -92.370
Lift-off point
40.850, -92.280
Record number
78

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
21:24 UTC22:00 UTCSevere Thunderstorm WarningDMX
21:42 UTC22:00 UTCTornado WarningDMX

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. The outlook in force was issued at 09:44 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.

Topeka, KS (KTOP), 12:00Z

9.5 hours before the tornado, 343 km from the path. March 13, 1990.

Skew-T log-pSkew-T log-p diagram, Topeka, KS at 12:00Z on 1990-03-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1521 joules per kilogram, CIN -86, lifted condensation level 766 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Topeka, KS at 12:00Z on 1990-03-13The 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 173 square meters per square second, 0 to 6 km bulk shear 52 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
1521 J/kg
Mixed-layer CIN
-86 J/kg
Surface CAPE
1077 J/kg
Mixed-layer LCL
766 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
37 kt
0-1 km storm-relative helicity
173 m²/s²
0-3 km storm-relative helicity
24 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.9
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

Topeka, KS (KTOP), 00:00Z

2.5 hours after it, 343 km from the path. March 14, 1990.

Skew-T log-pSkew-T log-p diagram, Topeka, KS at 00:00Z on 1990-03-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1053 joules per kilogram, CIN -14, lifted condensation level 623 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°0°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, Topeka, KS at 00:00Z on 1990-03-14The 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 246 square meters per square second, 0 to 6 km bulk shear 49 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
1053 J/kg
Mixed-layer CIN
-14 J/kg
Surface CAPE
625 J/kg
Mixed-layer LCL
623 m above ground
0-6 km bulk shear
49 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
246 m²/s²
0-3 km storm-relative helicity
268 m²/s²
Significant tornado parameter
1.5
Supercell composite
6.9
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

The surface observations

Ottumwa (OTM), 40 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:33 UTC170° 14 kt1010.2
20:00 UTC6764190° 13 kt1009.8TSRA
21:00 UTC6563180° 9 kt1009.1TSRA
21:59 UTC190° 14 kt1008.5
22:00 UTC6563180° 14 kt1008.5TSRA
23:00 UTC6563160° 12 kt1007.8FG

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

This ground now

The live radar over the trackEvery 1990 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of March 13, 1990

58 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
March 1312:10 AM CSTF1Jefferson, KS3.0100$50,000 to $500,000
March 138:36 AM CSTF1Hodgeman, KS1.023
March 134:31 PM CSTF0Sac, IA0.350$500 to $5,000
March 134:34 PM CSTF5Reno, KS48.01,320160$5 million to $50 million
March 134:42 PM CSTF0Scott, IA0.273$500 to $5,000
March 134:44 PM CSTF2Grady, OK28.02001$500,000 to $5 million
March 134:45 PM CSTF3Rock Island, IA to IL15.52501$50,000 to $500,000
March 134:45 PM CSTF1Buffalo, NE1.080$50 to $500
March 134:48 PM CSTF1Smith, KS13.0220$5,000 to $50,000
March 134:53 PM CSTF4Linn, IA19.0200$5 million to $50 million
March 134:55 PM CSTF1Scott, IA13.073$50,000 to $500,000
March 135:00 PM CSTF3Kearney, NE32.0200$500,000 to $5 million
March 135:00 PM CSTF1Jewell, KS1.5100$5,000 to $50,000
March 135:05 PM CSTF4Webster, NE131.04408$5 million to $50 million
March 135:08 PM CSTF1Jones, IA6.030$500,000 to $5 million
March 135:10 PM CSTF1Pottawattamie, IA8.040$50,000 to $500,000
March 135:15 PM CSTF3Grant, OK19.0200$50,000 to $500,000
March 135:20 PM CSTF2Kearney, NE8.0100$50,000 to $500,000
March 135:25 PM CSTF2Adams, NE9.080$50,000 to $500,000
March 135:30 PM CSTF0Throckmorton, TX0.210
March 135:30 PM CSTF5Harvey, KS22.01,3201$5 million to $50 million
March 135:31 PM CSTF2McClain, OK18.0150$50,000 to $500,000
March 135:35 PM CSTF0Buffalo, NE0.140under $50
March 135:44 PM CSTF3Hall, NE27.0200$500,000 to $5 million
March 135:53 PM CSTF1Cleveland, OK5.050
March 135:54 PM CSTF3Grant, OK to KS22.0200$500,000 to $5 million
March 135:55 PM CSTF1Dubuque, IA3.023$5,000 to $50,000
March 135:59 PM CSTF2Cleveland, OK19.02001$50,000 to $500,000
March 136:01 PM CSTF1Jefferson, OK21.073
March 136:04 PM CSTF0Sumner, KS0.150
March 136:12 PM CSTF0Sumner, KS0.150
March 136:15 PM CSTF2Marion, KS55.0220$500,000 to $5 million
March 136:20 PM CSTF1Jewell, KS5.0440$50,000 to $500,000
March 136:23 PM CSTF2Merrick, NE13.0100$500,000 to $5 million
March 136:25 PM CSTF1Boone, NE1.5200$50,000 to $500,000
March 136:30 PM CSTF1Nance, NE2.050$5,000 to $50,000
March 136:35 PM CSTF1Harper, KS12.050$50,000 to $500,000
March 136:45 PM CSTF1Madison, NE0.250$5,000 to $50,000
March 136:45 PM CSTF1Jewell, KS13.0550$50,000 to $500,000
March 136:55 PM CSTF3McPherson, KS18.0200$50,000 to $500,000
March 136:58 PM CSTF3Jefferson, OK22.02001$500,000 to $5 million
March 137:00 PM CSTF2Republic, KS15.0440$500,000 to $5 million
March 137:16 PM CSTF0Republic, KS0.510
March 137:20 PM CSTF0Dallas, IA0.113$500 to $5,000
March 137:25 PM CSTF2Boone, IA22.050$500,000 to $5 million
March 137:30 PM CSTF1Madison, NE0.673$500,000 to $5 million
March 137:35 PM CSTF1Boone, IA1.030$50,000 to $500,000
March 137:45 PM CSTF3Thayer, NE25.0180$500,000 to $5 million
March 137:45 PM CSTF3Thayer, NE13.0150$50,000 to $500,000
March 137:50 PM CSTF2Garvin, OK28.0150$500,000 to $5 million
March 137:50 PM CSTF0Saline, KS0.210
March 137:55 PM CSTF2Polk, IA15.06015$500,000 to $5 million
March 138:03 PM CSTF1Pottawatomie, KS2.050$50,000 to $500,000
March 138:10 PM CSTF2Okmulgee, OK9.0340$50,000 to $500,000
March 138:36 PM CSTF3Story, IA9.01001$50,000 to $500,000
March 138:40 PM CSTF0Cloud, KS0.210
March 139:30 PM CSTF2Polk, MO2.0600$500,000 to $5 million
March 1310:01 PM CSTF1Thurston, NE1.550$50,000 to $500,000

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.