Tornadoes · United States · Illinois · 1966

F2 tornado, Brown County, Illinois, October 14, 1966

This F2 tornado ran 1.0 miles across Brown County on October 14, 1966, touching down at 9:05 PM GMT-5 and reaching 100 yards wide. It killed nobody and injured 20, and did $500,000 to $5 million of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mphthis tornado

    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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F2
Date
October 14, 1966
Touchdown
9:05 PM GMT-5 (02:05 UTC)
Path length
1.0 miles (1.6 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
20
Property damage
$500,000 to $5 million
County
Brown County
Touchdown point
39.980, -90.750
Record number
551

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.

Peoria Regional, IL (KPIA), 00:00Z

2.1 hours before the tornado, 124 km from the path. October 15, 1966.

Skew-T log-pSkew-T log-p diagram, Peoria Regional, IL at 00:00Z on 1966-10-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 160 joules per kilogram, CIN -62, lifted condensation level 667 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, Peoria Regional, IL at 00:00Z on 1966-10-15The 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 264 square meters per square second, 0 to 6 km bulk shear 60 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
160 J/kg
Mixed-layer CIN
-62 J/kg
Surface CAPE
179 J/kg
Mixed-layer LCL
667 m above ground
0-6 km bulk shear
60 kt
0-1 km bulk shear
31 kt
0-1 km storm-relative helicity
264 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.2
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

Peoria Regional, IL (KPIA), 12:00Z

9.9 hours after it, 124 km from the path. October 15, 1966.

Skew-T log-pSkew-T log-p diagram, Peoria Regional, IL at 12:00Z on 1966-10-15Temperature 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 -17102, lifted condensation level 704 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, Peoria Regional, IL at 12:00Z on 1966-10-15The 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 44 square meters per square second, 0 to 6 km bulk shear 68 knots.1939587897117136Sfc1 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
-17102 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
704 m above ground
0-6 km bulk shear
68 kt
0-1 km bulk shear
23 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
179 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.1 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1966 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of October 14, 1966

21 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 141:15 PM GMT-5F2Taylor, IA1.5100$5,000 to $50,000
October 141:55 PM GMT-5F2Freeborn, MN2.7101$500 to $5,000
October 142:55 PM GMT-5F5Belmond tornado, IA9.71,0006172$5 million to $50 million
October 143:00 PM GMT-5F1Allamakee, IA0.110$500 to $5,000
October 143:25 PM GMT-5F1Dallas, MO3.0220$5,000 to $50,000
October 143:32 PM GMT-5F3Jasper, IA29.5200$5,000 to $50,000
October 143:50 PM GMT-5F2Taylor, IA0.110
October 144:00 PM GMT-5F2Linn, IA5.010$50,000 to $500,000
October 144:10 PM GMT-5F2Camden, MO14.950$5,000 to $50,000
October 144:15 PM GMT-5F1Ringgold, IA0.110$500 to $5,000
October 144:20 PM GMT-5F1Linn, IA0.110$5,000 to $50,000
October 144:25 PM GMT-5F2Moniteau, MO7.650$5,000 to $50,000
October 144:30 PM GMT-5F2Miller, MO4.950$5,000 to $50,000
October 145:00 PM GMT-5F2Polk, IA13.550$500,000 to $5 million
October 145:45 PM GMT-5F2Morgan, MO2.350$5,000 to $50,000
October 146:30 PM GMT-5F1Cole, MO3.350$5,000 to $50,000
October 146:30 PM GMT-5F2Laclede, MO5.233$5,000 to $50,000
October 146:30 PM GMT-5F2Grundy, IA2.7100$500 to $5,000
October 147:00 PM GMT-5F2Pulaski, MO13.71506$500,000 to $5 million
October 147:25 PM GMT-5F0Fayette, IA0.110under $50
October 1410:10 PM GMT-5F3Saint Charles, MO2.715026$500,000 to $5 million

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.