Tornadoes · United States · Illinois · 2010

EF0 tornado, Hume to Mortimer, Illinois, May 21, 2010

From Hume to Mortimer, this EF0 tornado ran 0.1 miles across Edgar County on May 21, 2010, touching down at 12:40 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 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 21, 2010
Touchdown
12:40 PM CDT (17:40 UTC)
Lifted
12:41 PM CDT (17:41 UTC)
On the ground
1 minutes
Path length
0.1 miles (0.2 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Edgar County
Touchdown point
39.846, -87.733
Lift-off point
39.847, -87.731
Record number
1005211140-01

What the Weather Service recorded

A low pressure system tracked from Missouri across central Illinois on May 21st, triggering scattered strong to severe thunderstorms along and east of I-57. Enough wind shear was present near the track of the low to create supercell thunderstorms with large hail, damaging winds and areas of flash flooding. In addition...two brief tornado touchdowns were reported in Edgar County as the storms tracked further eastward toward Indiana.

A tornado briefly touched down 1 mile south of Hume. No damage was reported.

A tornado briefly touched down northeast of Metcalf. No damage was reported.

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

The warnings

17 minutes of warning. NWS ILX issued a tornado warning for this county at 17:23 UTC, 17 minutes before the tornado touched down, in force until 18:00 UTC.

Issued (UTC)ExpiredProductOffice
17:23 UTC18:00 UTCTornado WarningILX
17:44 UTC18:30 UTCSevere Thunderstorm WarningILX
18:50 UTC00:43 UTCFlash Flood 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 General Thunderstorms Risk. The outlook in force was issued at 16:25 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

5.7 hours before the tornado, 81 km from the path. May 21, 2010.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2010-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 216 joules per kilogram, CIN -42, lifted condensation level 586 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 2010-05-21The 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 66 square meters per square second, 0 to 6 km bulk shear 20 knots.1939Sfc1 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
216 J/kg
Mixed-layer CIN
-42 J/kg
Surface CAPE
108 J/kg
Mixed-layer LCL
586 m above ground
0-6 km bulk shear
20 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

6.3 hours after it, 81 km from the path. May 22, 2010.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2010-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 354 joules per kilogram, CIN 0, lifted condensation level 525 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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 00:00Z on 2010-05-22The 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 50 square meters per square second, 0 to 6 km bulk shear 18 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
354 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
708 J/kg
Mixed-layer LCL
525 m above ground
0-6 km bulk shear
18 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

The radar

The Indianapolis radar (KIND), 125 km away, was scanning. The volume nearest the touchdown began at 17:41 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
17:20 UTCTORNADO1 S HumeEdgar, ILPUBLIC REPORT OF BRIEF TOUCHDOWN. NO DAMAGE REPORTED.
17:24 UTCTORNADO1 W MetcalfEdgar, ILPUBLIC REPORT OF BRIEF TOUCHDOWN. NO DAMAGE REPORTED.
17:25 UTCFUNNEL CLOUD1 W MetcalfEdgar, ILTRAINED SPOTTER REPORTED A FUNNEL CLOUD BUT COULD NOT DETERMINE IF IT TOUCHED DOWN DUE TO TREES IN THE WAY. TIME ESTIMATED.
17:25 UTCTSTM WND DMG2 S MetcalfEdgar, ILROOF TORN OFF BARN IN RURAL SHILOH TOWNSHIP. TIME ESTIMATED.
17:40 UTCTORNADO5 Ne MetcalfEdgar, ILPUBLIC REPORT OF BRIEF TOUCHDOWN. NO DAMAGE REPORTED.
18:18 UTCHEAVY RAIN 1.96MartinsvilleClark, ILSTORM TOTAL MEASURED OVER A 1 HOUR AND 15 MINUTE TIME FRAME.
18:20 UTCHAIL 1MarshallClark, IL
18:22 UTCHAIL 0.884 Ssw MarshallClark, ILDIME TO NICKEL SIZE
18:22 UTCHAIL 0.88MarshallClark, IL
18:22 UTCHAIL 1.752 Sw MarshallClark, IL
18:33 UTCHEAVY RAIN 1.51 N MartinsvilleClark, ILHAPPENED IN LESS THAN AN HOUR. CREEKS OVERFLOWING.
19:10 UTCFLASH FLOOD1 E HumeEdgar, ILDITCHES OVERFLOWING AND WATER SEVERAL INCHES DEEP FLOWING OVER ROADS BETWEEN HUME AND METCALF. TIME ESTIMATED.
19:10 UTCHEAVY RAIN 1.875 Nw SidellVermilion, IL
19:24 UTCFLASH FLOODIndianolaVermilion, ILSEVERE FLOODING AND MOST ROADS ARE INPASSABLE.

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

This ground now

The live radar over the trackEvery 2010 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of May 21, 2010

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 2112:20 PM CDTEF0Edgar, IL0.110
May 216:44 PM EDTEF1Brown, OH4.350$110,000
May 214:59 PM MDTEF0Platte, WY0.320
May 217:28 PM CDTEF1Hardin, KY1.875$35,000
May 218:44 PM EDTEF1Adams, OH3.075$135,000

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.