Tornadoes · United States · Illinois · 2021

EF0 tornado, Louisville to Camp Travis, Illinois, May 27, 2021

From Louisville to Camp Travis, this EF0 tornado ran 2.8 miles across Clay County on May 27, 2021, touching down at 3:43 PM CDT and reaching 50 yards wide. It killed nobody, and did $45,000 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.

  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
May 27, 2021
Touchdown
3:43 PM CDT (20:43 UTC)
Lifted
3:49 PM CDT (20:49 UTC)
On the ground
6 minutes
Path length
2.8 miles (4.4 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$45,000
County
Clay County
Touchdown point
38.744, -88.337
Lift-off point
38.720, -88.296
Record number
2105271443-01

The damage survey

7 damage points were recorded along this path by NWS ILX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 80 mph.

  • Tornado end point. No damage in open field.
  • Tin from old barn roof strewn in field.
  • Several uprooted trees near Gaskin Lake

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

Clusters of thunderstorms developed along and just south of a warm front draped across south-central Illinois during the late morning and afternoon of May 27th. The storms primarily impacted locations along and south of a Jacksonville...to Shelbyville...to Robinson line. Two brief tornadoes touched down in Clay County, with only minor damage reported. Elsewhere, scattered wind gusts of around 60mph downed a few trees and powerlines.

A tornado touched down in an open field about 2.9 miles east-southeast of Louisville at 3:29 PM CDT before quickly dissipating at 3:31 PM CDT. No damage was observed.

A tornado touched down 1.8 miles southeast of Sailor Springs at 3:43 PM CDT. The tornado tracked southeastward and knocked down a few trees and did minor damage to a barn before dissipating at 3:49 PM CDT about 4.6 miles southeast of Sailor Springs.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

The county was under a severe thunderstorm watch, issued at 16:27 UTC and running to 22:35 UTC.

Issued (UTC)ExpiredProductOffice
16:27 UTC22:35 UTCSevere Thunderstorm WatchILX
20:06 UTC21:00 UTCSevere Thunderstorm WarningILX

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 20:00 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.

Lincoln, IL (KILX), 12:00Z

8.7 hours before the tornado, 160 km from the path. May 27, 2021.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2021-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -93851, lifted condensation level 1679 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Lincoln, IL at 12:00Z on 2021-05-27The 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 130 square meters per square second, 0 to 6 km bulk shear 34 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
0 J/kg
Mixed-layer CIN
-93851 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1679 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.1 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

3.3 hours after it, 160 km from the path. May 28, 2021.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2021-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 115 joules per kilogram, CIN -65, lifted condensation level 838 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, Lincoln, IL at 00:00Z on 2021-05-28The 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 26 square meters per square second, 0 to 6 km bulk shear 45 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
115 J/kg
Mixed-layer CIN
-65 J/kg
Surface CAPE
762 J/kg
Mixed-layer LCL
838 m above ground
0-6 km bulk shear
45 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

The radar

The Evansville,IN radar (KVWX), 73 km away, was scanning. The volume nearest the touchdown began at 20:43 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
20:15 UTCTSTM WND DMGXeniaClay, ILPOWER LINE DOWN. RELAYED BY EMA. TIME ESTIMATED BY RADAR.
20:30 UTCTORNADO3 E LouisvilleClay, ILNO DAMAGE REPORTED, TOUCHED DOWN IN FIELD.
20:38 UTCTSTM WND DMGClay CityClay, ILTREE FELL ON CARS. RELAYED BY EMA.
20:45 UTCTSTM WND DMG3 Ne Clay CityClay, ILTREE DAMAGE, MINOR STRUCTURE DAMAGE.
20:45 UTCTSTM WND DMG3 Nne Clay CityClay, ILTREES DOWNED.
20:45 UTCTORNADO2 Se Sailor SpringsClay, ILDAMAGE TO BARN AND DEBRIS THROUGH FIELD.

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

This ground now

The live radar over the trackEvery 2021 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of May 27, 2021

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 2711:51 AM CDTEF1Polk, MO0.150$300,000
May 2712:08 PM CDTEF1Polk, MO1.250$75,000
May 271:16 PM CDTEF0Kingfisher, OK0.110
May 273:29 PM CDTUnratedClay, IL0.210
May 277:13 PM CDTEF1McIntosh, OK3.0500$25,000

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.