Tornadoes · United States · Illinois · 2012

EF0 tornado, Monticello Arpt, Illinois, May 1, 2012

This EF0 tornado ran 0.1 miles across Piatt County on May 1, 2012, touching down at 3:59 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 1, 2012
Touchdown
3:59 PM CDT (20:59 UTC)
Lifted
4:00 PM CDT (21:00 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
Piatt County
Touchdown point
39.982, -88.490
Lift-off point
39.983, -88.487
Record number
1205011459-01

What the Weather Service recorded

Isolated supercell thunderstorms developed along an advancing warm front during the afternoon of May 1st. The storms produced 4 tornadoes across portions of Piatt, Champaign, and Vermilion counties. Only minor damage was noted.

A tornado briefly touched down in a field southeast of Monticello. No damage was reported.

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.

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, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:52 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

9.0 hours before the tornado, 21 km from the path. May 1, 2012.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2012-05-01Temperature 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 -55837, lifted condensation level 660 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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 2012-05-01The 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 123 square meters per square second, 0 to 6 km bulk shear 38 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
0 J/kg
Mixed-layer CIN
-55837 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
660 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
138 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.9 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

3.0 hours after it, 21 km from the path. May 2, 2012.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2012-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 579 joules per kilogram, CIN -49, lifted condensation level 1059 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 00:00Z on 2012-05-02The 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 166 square meters per square second, 0 to 6 km bulk shear 32 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
579 J/kg
Mixed-layer CIN
-49 J/kg
Surface CAPE
1500 J/kg
Mixed-layer LCL
1059 m above ground
0-6 km bulk shear
32 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
166 m²/s²
0-3 km storm-relative helicity
237 m²/s²
Significant tornado parameter
0.3
Supercell composite
4.0
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

The surface observations

Champaign - Willard (CMI), 19 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:09 UTC66.264.4130° 11 kt1012.2
19:41 UTC69.866.2140° 10 kt1011.9
19:48 UTC69.866.2140° 9 kt1011.9
19:53 UTC7167130° 10 kt1011.5BR
20:00 UTC71.666.2150° 9 kt1011.5HZ
20:36 UTC73.468170° 9 kt1010.5
20:51 UTC73.468150° 7 kt1010.2-TSRA
20:53 UTC7368150° 6 kt1010.2-TSRA
21:10 UTC71.668170° 10 kt1009.8+TSRA BR
21:14 UTC71.668200° 9 kt1009.5FC +TSRA BR
21:42 UTC75.266.2230° 18 kt231009.8TS
21:44 UTC7766.2240° 16 kt231009.8VCTS
21:53 UTC7768240° 15 kt211009.8VCTS
21:56 UTC75.266.2240° 16 kt211009.8
22:53 UTC7666240° 12 kt1009.8

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

The radar

The Lincoln radar (KILX), 75 km away, was scanning. The volume nearest the touchdown began at 20:59 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
20:45 UTCFUNNEL CLOUDMonticelloPiatt, IL
21:07 UTCFUNNEL CLOUD7 Ese MonticelloChampaign, IL
21:09 UTCTORNADO5 Ese MonticelloPiatt, ILBRIEF TOUCHDOWN IN FARM FIELD
21:12 UTCTORNADO7 Ese MonticelloChampaign, ILBRIEF TOUCHDOWN IN FARM FIELD.
21:15 UTCTORNADO4 Sw SavoyChampaign, ILTORNADO IN FARM FIELD NEAR 900N AND 500 E. FROM PIATT CO. EMA.
21:15 UTCTORNADO6 Sw SavoyChampaign, ILTORNADO WAS ON GROUND FOR 7 MINUTES. FROM PIATT CO EMA.
21:32 UTCHAIL 1St. JosephChampaign, IL
21:43 UTCTORNADOSidneyChampaign, ILBRIEF TOUCHDOWN ON WEST SIDE OF SIDNEY.
21:47 UTCHAIL 12 N HomerChampaign, ILSWOP REPORT. RELAYED BY CHAMPAIGN EMA. CORRECTED HAIL SIZE.
21:47 UTCHAIL 22 N HomerChampaign, ILSWOP REPORT. RELAYED BY CHAMPAIGN EMA.
21:49 UTCHAIL 0.5OgdenChampaign, IL

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

This ground now

The live radar over the trackEvery 2012 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of May 1, 2012

16 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 11:30 AM CDTEF2Craig, OK1.01501$250,000
May 12:33 PM EDTEF0Clay, IN0.150$3,000
May 14:45 PM EDTEF0Trimble, KY1.915$25,000
May 14:06 PM CDTEF1Champaign, IL8.175$25,000
May 15:28 PM EDTEF1Franklin, IN1.3100$250,000
May 14:40 PM CDTEF0Champaign, IL0.120
May 14:48 PM CDTEF0Pope, MN0.150
May 14:56 PM CDTEF0Stearns, MN0.975
May 15:05 PM CDTEF0Stearns, MN2.175$100,000
May 15:18 PM CDTEF0Vermilion, IL0.530$8,000
May 16:20 PM EDTEF0Warren, OH0.010$5,000
May 16:24 PM EDTEF0Warren, OH0.050$10,000
May 15:40 PM CDTEF0Wright, MN0.025
May 16:57 PM EDTEF0Fountain, IN0.150
May 17:36 PM EDTEF1Montgomery, IN0.5150$48,000
May 19:40 PM CDTEF0Clay, IA2.650$5,000

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.