Tornadoes · United States · Illinois · 2021

Unrated tornado, Florid, Illinois, October 11, 2021

This Unrated tornado ran 0.0 miles across Putnam County on October 11, 2021, touching down at 5:47 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
October 11, 2021
Touchdown
5:47 PM CDT (22:47 UTC)
Lifted
5:48 PM CDT (22:48 UTC)
On the ground
1 minutes
Path length
0.0 miles (0.0 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Putnam County
Touchdown point
41.180, -89.310
Lift-off point
41.180, -89.310
Record number
2110111647-01

The damage survey

1 damage points were recorded along this path by NWS DVN, in the Damage Assessment Toolkit the survey teams carry.

  • Brief 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

Showers and thunderstorms moved across parts of northern Illinois on the afternoon and evening of October 11, 2021 produced brief severe weather. A storm chaser reported a brief tornado touch down near McNabb, IL. There was no visible damage to assign an EF-scale rating.

A storm chaser reported a brief tornado. There was no visible damage to assign an EF-scale rating.

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

The warnings

35 minutes of warning. NWS DVN issued a tornado warning for this county at 22:12 UTC, 35 minutes before the tornado touched down, in force until 23:00 UTC.

The county was under a tornado watch, issued at 20:11 UTC and running to 00:27 UTC.

Issued (UTC)ExpiredProductOffice
20:11 UTC00:27 UTCTornado WatchDVN
22:12 UTC23:00 UTCTornado WarningDVN
22:58 UTC23:45 UTCTornado WarningDVN

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 19:39 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

10.8 hours before the tornado, 111 km from the path. October 11, 2021.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2021-10-11Temperature 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 -92062, lifted condensation level 798 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, Davenport, at 12:00Z on 2021-10-11The 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 108 square meters per square second, 0 to 6 km bulk shear 38 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
-92062 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
798 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.2 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

1.2 hours after it, 111 km from the path. October 12, 2021.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2021-10-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1 joules per kilogram, CIN -100, lifted condensation level 818 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, Davenport, at 00:00Z on 2021-10-12The 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 -24 square meters per square second, 0 to 6 km bulk shear 12 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
1 J/kg
Mixed-layer CIN
-100 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
818 m above ground
0-6 km bulk shear
12 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
-24 m²/s²
0-3 km storm-relative helicity
2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

The surface observations

Lacon (C75), 19 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:55 UTC7265.7130° 17 kt221000.7
21:15 UTC71.666130° 13 kt181001
21:35 UTC72.566.4130° 10 kt171000.3
21:55 UTC71.865.8120° 8 kt14999.7
22:15 UTC7165.7110° 5 kt999.7-RA
22:35 UTC62.858.8230° 17 kt231001.7+RA
22:55 UTC60.359150° 5 kt1002+VCTSRA
23:15 UTC60.459.40° 0 kt1001.4RA
23:35 UTC60.8600° 0 kt1001-RA
23:55 UTC61.260190° 3 kt1001.4RA
00:15 UTC61.260.3200° 4 kt1002.4
00:35 UTC61.760.4200° 5 kt1002.7

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

The radar

The Chicago radar (KLOT), 113 km away, was scanning. The volume nearest the touchdown began at 22:46 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
21:28 UTCTORNADO3 N RoanokeWoodford, ILCORRECTION TO TIME. CORRECTS PREVIOUS TORNADO REPORT FROM 3 N ROANOKE. BRIEFLY TOUCHED DOWN.
21:34 UTCFUNNEL CLOUDRoanokeWoodford, IL
21:45 UTCTORNADO3 N RoanokeWoodford, ILBRIEFLY TOUCHED DOWN.
21:45 UTCTORNADO4 E WashburnWoodford, ILCORRECTION TO TIME. CORRECTS PREVIOUS TORNADO REPORT FROM 4 E WASHBURN. FARM HAS SEVERAL TREE BRANCHES DOWN, GARAGE DAMAGE, AND A BARN KNOCKED DOWN. DAMAGE RELAYED FROM NWS CHICAGO.
21:55 UTCTORNADO4 E WashburnWoodford, ILFARM HAS SEVERAL TREE BRANCHES DOWN, GARAGE DAMAGE, AND A BARN KNOCKED DOWN. DAMAGE RELAYED FROM NWS CHICAGO.
21:55 UTCTORNADO4 E WashburnWoodford, IL
22:35 UTCFUNNEL CLOUD1 Ssw El PasoWoodford, IL
22:39 UTCTORNADO2 Sw El PasoWoodford, ILLATE REPORT. AN EF-U TORNADO TOUCHED DOWN IN AN OPEN FIELD AND TRAVELED NORTH-NORTHEAST ACROSS HWY 24. PATH LENGTH WAS 2.5 MILES WITH A PATH WIDTH OF 50 YEARDS.
22:47 UTCTORNADO4 Ssw FloridPutnam, ILDELAYED REPORT. BRIEF TOUCH DOWN WITH NO VISIBLE DAMAGE.
23:30 UTCTORNADO3 Ne Troy GroveLa Salle, ILLOCATION BASED ON SPOTTER REPORT AND RADAR. SPOTTER REPORTED A BRIEF TOUCHDOWN OF 30 TO 45 SECONDS.
23:55 UTCHEAVY RAIN 1.12Marshall County AirportMarshall, ILAWOS STATION KC75 MARSHALL COUNTY ARPT.
00:00 UTCHEAVY RAIN 1.333 N PanolaWoodford, ILMESONET STATION 8089D 2 N PANOLA.

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 October 11, 2021

9 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 111:08 AM CDTEF1Newton, MO3.390$75,000
October 114:44 AM CDTEF0Jasper, MO2.450$80,000
October 112:37 PM CDTEF2Greene, IL5.875$100,000
October 113:26 PM CDTEF0Morgan, IL1.450
October 114:28 PM CDTUnratedWoodford, IL0.330
October 114:45 PM CDTEF0Woodford, IL2.575
October 115:10 PM CDTEF0Lake, IL to IN1.670
October 115:39 PM CDTUnratedWoodford, IL2.550
October 116:30 PM CDTUnratedLaSalle, IL0.440

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.