Tornadoes · United States · Illinois · 2021

Unrated tornado, Altamont to Edgewood, Illinois, May 6, 2021

From Altamont to Edgewood, this Unrated tornado ran 0.1 miles across Effingham County on May 6, 2021, touching down at 3:30 PM CDT and reaching 10 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 mph

    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. Unratedthis tornado

    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
Unrated
Date
May 6, 2021
Touchdown
3:30 PM CDT (20:30 UTC)
Lifted
3:31 PM CDT (20:31 UTC)
On the ground
1 minutes
Path length
0.1 miles (0.1 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Effingham County
Touchdown point
38.938, -88.660
Lift-off point
38.937, -88.659
Record number
2105061430-01

The damage survey

2 damage points were recorded along this path by NWS ILX, in the Damage Assessment Toolkit the survey teams carry. The highest wind the damage implies is 70 mph.

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

A cold front triggered a broken line of strong to severe thunderstorms across south-central Illinois during the afternoon of May 6th. Four brief tornado touchdowns occurred with the stronger cells, including one that did minor damage to a property just southwest of Assumption in Christian County. Other thunderstorms dropped hail as large as quarters and produced minor wind damage.

A tornado touched down in a field 1.9 miles south of Altamont at 3:10 PM CDT. The tornado quickly dissipated by 3:11 PM CDT. No damage occurred.

A tornado touched down in a field about 0.9 miles north of Edgewood near mile marker 145 on I-57 at 3:30 PM CDT. The tornado quickly dissipated by 3:31 PM CDT. No damage occurred.

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.

Issued (UTC)ExpiredProductOffice
20:01 UTC20:28 UTCSevere Thunderstorm WarningILX
20:22 UTC20:47 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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:37 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

8.5 hours before the tornado, 135 km from the path. May 6, 2021.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2021-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 16 joules per kilogram, CIN -111, lifted condensation level 1453 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, Lincoln, IL at 12:00Z on 2021-05-06The 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 203 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
16 J/kg
Mixed-layer CIN
-111 J/kg
Surface CAPE
9 J/kg
Mixed-layer LCL
1453 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
203 m²/s²
0-3 km storm-relative helicity
211 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.1 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

3.5 hours after it, 135 km from the path. May 7, 2021.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2021-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 18 joules per kilogram, CIN -5, lifted condensation level 1805 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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, Lincoln, IL at 00:00Z on 2021-05-07The 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 -13 square meters per square second, 0 to 6 km bulk shear 31 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
18 J/kg
Mixed-layer CIN
-5 J/kg
Surface CAPE
76 J/kg
Mixed-layer LCL
1805 m above ground
0-6 km bulk shear
31 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
-12 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
8.0 K/km

Open this sounding in Storm Lab

The surface observations

Effingham (1H2), 18 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:35 UTC5849.6150° 4 kt1017.3TS
18:55 UTC57.450.5170° 3 kt1017.3VCTS
19:15 UTC5849.6180° 5 kt1017.3
19:35 UTC60.450170° 7 kt1016.6VCTS
19:55 UTC6250.5190° 6 kt1016.3
20:15 UTC60.349.8220° 7 kt1016.3
20:35 UTC5851.8240° 10 kt1016.3-VCTSRA
20:55 UTC59.251320° 5 kt171016.3
21:15 UTC62.450300° 20 kt271016.3VCTS
21:35 UTC6247.3310° 18 kt281016.9
21:55 UTC61.746310° 20 kt281017.6
22:15 UTC60.845310° 19 kt271017.9

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

The radar

The Evansville,IN radar (KVWX), 111 km away, was scanning. The volume nearest the touchdown began at 20:28 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
18:24 UTCHAIL 13 Ene XeniaClay, ILVIA COUNTY ESDA, QUARTER SIZE HAIL REPORTED NEAR DOGWOOD RD AND OLD US 50.
19:29 UTCFUNNEL CLOUDShelbyvilleShelby, IL
20:07 UTCHAIL 0.72 Ene WindsorMoultrie, ILDIME SIZE HAIL. CORRECTED LOCATION FROM 2 ENE HOOPESTON.
20:10 UTCFUNNEL CLOUDAltamontEffingham, ILCLOSE TO TOUCHING THE GROUND.
20:10 UTCTORNADO2 S AltamontEffingham, ILBRIEF TOUCHDOWN.
20:30 UTCTORNADOMasonEffingham, ILBRIEF TOUCHDOWN, BUT WAS CLOSE TO TOUCHING DOWN AGAIN.
20:38 UTCHAIL 0.25OdinMarion, ILSPOTTER REPORT OF PEA SIZE HAIL JUST SOUTH OF ODIN.
20:40 UTCFUNNEL CLOUD1 N IolaClay, ILUNABLE TO TELL IF IT WAS REACHING THE GROUND.
21:52 UTCFUNNEL CLOUD4 Se Flora Municipal AiClay, ILCORRECTS PREVIOUS TORNADO REPORT FROM 4 SE FLORA MUNICIPAL AIRPORT. TOUCH DOWN OCCURRED ON THE WAYNE COUNTY SIDE.
21:52 UTCTORNADO4 Se Flora Municipal AiClay, ILBRIEF TOUCHDOWN REPORTED BY EMA.
22:00 UTCTORNADO4 Nne CisneWayne, ILASSISTANT EM DIRECTOR OF CLAY COUNTY IL OBSERVED A BRIEF TORNADO TOUCHDOWN ABOUT 2 MILES EAST OF RINARD NEAR PITTMAN CEMETERY. THE TORNADO WAS OBSERVED TO PICK UP LEAVES AND WAS ON THE GROUND FOR LESS THAN A MINUTE.
22:01 UTCTORNADO2 S NobleRichland, ILLOCAL LAW ENFORCEMENT REPORTED A TORNADO BRIEFLY TOUCHED DOWN NEAR CR 400E SOUTH OF NOBLE. NO DAMAGE WAS REPORTED.

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 6, 2021

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 62:11 PM CDTEF0Christian, IL0.220$25,000
May 63:10 PM CDTUnratedEffingham, IL0.110
May 65:00 PM CDTEF0Wayne, IL0.530
May 65:01 PM CDTUnratedRichland, IL0.110

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.