Tornadoes · United States · Illinois · 2006

F0 tornado, LaSalle County, Illinois, April 14, 2006

This F0 tornado ran 0.5 miles across LaSalle County on April 14, 2006, touching down at 6:33 PM CDT and reaching 25 yards wide. It killed nobody.

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 mphthis tornado

    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 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. 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
F0
Date
April 14, 2006
Touchdown
6:33 PM CDT (23:33 UTC)
Path length
0.5 miles (0.8 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
LaSalle County
Touchdown point
41.250, -88.830
Lift-off point
41.250, -88.820
Record number
369

The warnings

11 minutes of warning. NWS LOT issued a tornado warning for this county at 23:22 UTC, 11 minutes before the tornado touched down, in force until 00:00 UTC.

The county was under a tornado watch, issued at 22:20 UTC and running to 01:33 UTC.

Issued (UTC)ExpiredProductOffice
05:47 UTC06:36 UTCSevere Thunderstorm WarningLOT
06:46 UTC07:30 UTCSevere Thunderstorm WarningLOT
06:58 UTC08:58 UTCTornado WatchLOT
22:20 UTC01:33 UTCTornado WatchLOT
23:06 UTC23:45 UTCSevere Thunderstorm WarningLOT
23:22 UTC00:00 UTCTornado WarningLOT

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 22:14 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

11.6 hours before the tornado, 124 km from the path. April 14, 2006.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2006-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1011 joules per kilogram, CIN -195, lifted condensation level 1797 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 2006-04-14The 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 254 square meters per square second, 0 to 6 km bulk shear 41 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
1011 J/kg
Mixed-layer CIN
-195 J/kg
Surface CAPE
845 J/kg
Mixed-layer LCL
1797 m above ground
0-6 km bulk shear
41 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
254 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

0.4 hours after it, 124 km from the path. April 15, 2006.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2006-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2079 joules per kilogram, CIN -17, lifted condensation level 1966 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 2006-04-15The 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 67 square meters per square second, 0 to 6 km bulk shear 41 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
2079 J/kg
Mixed-layer CIN
-17 J/kg
Surface CAPE
2387 J/kg
Mixed-layer LCL
1966 m above ground
0-6 km bulk shear
41 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
285 m²/s²
Significant tornado parameter
0.1
Supercell composite
13.7
0-3 km lapse rate
8.4 K/km

Open this sounding in Storm Lab

The surface observations

Peru (VYS), 30 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
21:45 UTC80.664.4210° 9 kt1001.4
22:05 UTC78.864.4220° 9 kt1001.4
22:25 UTC80.664.4220° 7 kt1001
22:45 UTC80.664.4190° 9 kt1000.7VCTS
23:05 UTC80.664.4220° 12 kt1000VCTS
23:25 UTC78.864.4280° 9 kt1000.7
23:45 UTC75.264.4330° 9 kt1001.4
00:05 UTC75.264.4350° 5 kt1001.4
00:25 UTC73.464.410° 4 kt1001.4
00:45 UTC73.464.4340° 3 kt1001.7
01:05 UTC71.664.40° 0 kt1001.7
01:25 UTC69.864.40° 0 kt1001.7

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

The radar

The Chicago radar (KLOT), 73 km away, was scanning. The volume nearest the touchdown began at 23:35 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
23:33 UTCHAIL 0.752 N OttawaLa Salle, IL
23:38 UTCHAIL 0.755 W OttawaLa Salle, IL
23:38 UTCHAIL 1.75MarseillesLa Salle, ILPENNY TO GOLFBALL SIZE HAIL.
23:47 UTCHAIL 0.88MinookaGrundy, IL

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

This ground now

The live radar over the trackEvery 2006 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of April 14, 2006

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 144:35 PM PDTF1Stanislaus, CA0.50$10,000
April 147:57 PM EDTF0Benton, IN0.525
April 147:58 PM EDTF0Tippecanoe, IN3.275
April 148:18 PM EDTF1Carroll, IN2.3100$60,000
April 1410:58 PM EDTF1Decatur, IN0.8530$100,000

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.