Tornadoes · United States · Iowa · 2018

EF0 tornado, Lafayette to Prairieburg, Iowa, September 3, 2018

From Lafayette to Prairieburg, this EF0 tornado ran 0.0 miles across Linn County on September 3, 2018, touching down at 6:08 PM CDT and reaching 15 yards wide. It killed nobody.

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.

  1. EF065 to 85 mphthis tornado

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

  2. EF186 to 110 mph

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

  3. 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.

  4. 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.

  5. EF4166 to 200 mph

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

  6. 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.

  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
EF0
Date
September 3, 2018
Touchdown
6:08 PM CDT (23:08 UTC)
Lifted
6:09 PM CDT (23:09 UTC)
On the ground
1 minutes
Path length
0.0 miles (0.0 km)
Path width
15 yards (14 m)
Deaths
0
Injuries
0
County
Linn County
Touchdown point
42.228, -91.450
Lift-off point
42.228, -91.450
Record number
1809031708-01

The damage survey

10 damage points were recorded along this path by NWS DVN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 110 mph.

  • Law enforcement observed a brief tornado touch down with no visible damage.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

Scattered showers and thunderstorms developed across eastern Iowa, northwest Illinois, and northeast Missouri during the afternoon and evening as an upper level disturbance tracked across the region. One supercell thunderstorm produced four tornadoes as it tracked across Benton and Linn counties during the late afternoon and early evening. Another storm produced a tornado on the west side of Cedar Rapids later in the evening.

A NWS storm survey determined an EF1 tornado touched down just northwest of Alburnett and moved east northeast along an intermittent path for around 5 miles. The tornado lifted southwest of Central City. The tornado damaged trees and crops, and some siding on one house.

Law enforcement observed a brief EF0 tornado touch down with no visible damage.

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

The warnings

3 minutes of warning. NWS DVN issued a tornado warning for this county at 23:05 UTC, 3 minutes before the tornado touched down, in force until 23:32 UTC.

Issued (UTC)ExpiredProductOffice
21:41 UTC22:15 UTCTornado WarningDVN
22:15 UTC23:00 UTCTornado WarningDVN
23:05 UTC23:32 UTCTornado WarningDVN
23:12 UTC01:36 UTCTornado WatchDVN

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 Marginal Risk. The outlook in force was issued at 19:40 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), 12:00Z

11.1 hours before the tornado, 104 km from the path. September 3, 2018.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2018-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1178 joules per kilogram, CIN -30, lifted condensation level 851 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 2018-09-03The 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 118 square meters per square second, 0 to 6 km bulk shear 26 knots.193958Sfc1 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
1178 J/kg
Mixed-layer CIN
-30 J/kg
Surface CAPE
481 J/kg
Mixed-layer LCL
851 m above ground
0-6 km bulk shear
26 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
118 m²/s²
0-3 km storm-relative helicity
107 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.5
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

0.9 hours after it, 104 km from the path. September 4, 2018.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2018-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 463 joules per kilogram, CIN -58, lifted condensation level 1273 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 2018-09-04The 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 111 square meters per square second, 0 to 6 km bulk shear 32 knots.193958Sfc1 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
463 J/kg
Mixed-layer CIN
-58 J/kg
Surface CAPE
1739 J/kg
Mixed-layer LCL
1273 m above ground
0-6 km bulk shear
32 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.6
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

The surface observations

Monticello Municipal (MXO), 24 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
21:10 UTC80.675.290° 6 kt1018.6
21:15 UTC80.675.2100° 4 kt1018.6
21:20 UTC80.675.2 3 kt1018.6
21:30 UTC80.675.270° 3 kt1018.6
21:35 UTC80.67780° 4 kt1018.6
21:40 UTC80.67770° 4 kt1018.6
21:50 UTC80.67770° 3 kt1019
21:55 UTC80.6770° 0 kt1019
22:00 UTC78.8770° 0 kt1019
22:10 UTC78.877110° 5 kt1019
22:15 UTC78.877100° 4 kt1018.6
22:20 UTC78.877 6 kt1018.6
22:30 UTC78.87790° 3 kt1019
22:35 UTC78.877 5 kt1019
22:40 UTC78.877130° 5 kt1018.6
22:50 UTC78.877110° 5 kt1019
22:55 UTC78.87790° 6 kt1018.3
23:00 UTC78.877100° 8 kt1018.6
23:10 UTC75.273.4150° 7 kt221019BR
23:15 UTC75.275.2120° 8 kt191018.6
23:20 UTC7775.2200° 6 kt141018.6
23:30 UTC7775.2100° 9 kt1018.3
23:35 UTC7775.2100° 9 kt1018.6
23:40 UTC7775.2120° 9 kt141018.6
23:50 UTC78.877120° 9 kt1019
23:55 UTC78.877120° 6 kt121018.6
00:00 UTC7777120° 7 kt1018.6
00:10 UTC7777110° 6 kt1018.6
00:15 UTC7775.2110° 7 kt1018.6
00:20 UTC7775.2110° 5 kt101019
00:30 UTC75.273.4110° 5 kt1019
00:35 UTC75.273.4120° 6 kt1019
00:40 UTC75.273.4110° 5 kt1019
00:50 UTC75.273.4110° 5 kt1019.3
00:55 UTC75.273.4100° 4 kt1019
01:00 UTC73.473.4100° 5 kt1019

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

The radar

The Quad Cities radar (KDVN), 99 km away, was scanning. The volume nearest the touchdown began at 23:11 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
21:40 UTCTORNADO4 Nw ShellsburgBenton, IAA TRAINED SPOTTER REPORTED A TORNADO 4 MILES NORTHWEST OF SHELLSBURG. THE REPORT WAS RELAYED BY EMERGENCY MANAGERS.
21:40 UTCTORNADO4 Sse VintonBenton, IATORNADO OBSERVED BY EMERGENCY MANAGEMENT NEAR THE INTERSECTION OF 63RD STREET AND 25TH AVE SOUTH OF VINTON. TORNADO BRIEFLY TOUCHED DOWN IN A FIELD WITH NO VISIBLE DAMAGE.
21:40 UTCTORNADO5 Ssw VintonBenton, IAEF0 BRIEF TOUCHDOWN IN FIELD OBSERVED BY SPOTTER.
21:46 UTCTORNADO4 Sse VintonBenton, IACORRECTS PREVIOUS TORNADO REPORT FROM 4 SSE VINTON. TORNADO OBSERVED BY EMERGENCY MANAGEMENT NEAR THE INTERSECTION OF 63RD STREET AND 25TH AVE SOUTH OF VINTON. TORNADO BRIEFLY TOUCHED DOWN IN A FIELD WITH NO VISIBLE DAMA
22:29 UTCTORNADO2 Nw AlburnettLinn, IAEF1 PEAK WINDS 110 MPH, PATH LENGTH 2.5 MILES, WIDTH 100 YARDS, DURATION 529 PM TO 536 PM.
22:37 UTCTORNADO2 N AlburnettLinn, IAEMA RELAYED REPORT OF A TORNADO ON THE GROUND NORTH OF ALBURNETT.
22:44 UTCTORNADO2 Sw Central City.Linn, IA2 DIFFERENT LAW ENFORCEMENT OFFICERS REPORTING A CYCLIC TORNADO ON THE GROUND.
23:08 UTCTORNADO1 Wsw PrairieburgLinn, IALAW ENFORCEMENT OBSERVED A BRIEF TORNADO WITH NO VISIBLE DAMAGE.
23:08 UTCTORNADO2 Sw PrairieburgLinn, IATORNADO TOUCHED DOWN AND THEN LIFTED BACK UP.
02:03 UTCHEAVY RAIN 1.321 E ParisLinn, IA
02:04 UTCTSTM WND DMGNw Cedar RapidsLinn, IATIME OF THE EVENT ESTIMATED BY RADAR. MULTIPLE REPORTS OF TREES DOWN OR SPLIT WITH POWER LINES DOWN. REPORTS VIA SOCIAL MEDIA.
02:07 UTCTORNADO3 W Cedar RapidsLinn, IAEF1 PEAK WINDS 100 MPH, PATH LENGTH 1.4 MILES, WIDTH 30 YARDS, DURATION 907 TO 910 PM.
02:08 UTCTORNADO3 W Cedar RapidsLinn, IACORRECTS PREVIOUS TORNADO REPORT FROM 3 W CEDAR RAPIDS. EF1 PEAK WINDS 100 MPH, PATH LENGTH 2.2 MILES, WIDTH 30 YARDS, DURATION 908 TO 914 PM.

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

This ground now

The live radar over the trackEvery 2018 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of September 3, 2018

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
September 32:14 PM CDTEF0Cook, IL1.775$10,000
September 34:40 PM CDTEF0Benton, IA0.015
September 34:45 PM CDTEF0Benton, IA0.015
September 35:31 PM CDTEF1Linn, IA5.0100
September 39:08 PM CDTEF1Linn, IA2.230$35,000

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.