Tornadoes · United States · Illinois · 2017

EF0 tornado, LaSalle County, Illinois, February 28, 2017

This EF0 tornado ran 1.8 miles across LaSalle County on February 28, 2017, touching down at 4:27 PM CST and reaching 50 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
February 28, 2017
Touchdown
4:27 PM CST (22:27 UTC)
Lifted
4:30 PM CST (22:30 UTC)
On the ground
3 minutes
Path length
1.8 miles (2.8 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
LaSalle County
Touchdown point
41.279, -89.163
Lift-off point
41.279, -89.129
Record number
1702281627-01

The damage survey

11 damage points were recorded along this path by NWS DVN and NWS LOT, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF3. The highest wind the damage implies is 155 mph.

  • Older house, cinderblock foundation, crawlspace, not necessarily well built so took the wind speed down 10-12 mph. A van and a car at the property also were moved. The car was flipped around facing the opposite direction while the van was probably either lifted or rolled about 30 yards.
  • Southern edge of the path looking north
  • Northern end of the damage path looking east
  • Nursing home roof removed.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

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

10.5 hours before the tornado, 119 km from the path. February 28, 2017.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2017-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 30 joules per kilogram, CIN -241, lifted condensation level 771 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 12:00Z on 2017-02-28The 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 223 square meters per square second, 0 to 6 km bulk shear 80 knots.1939587897117Sfc1 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
30 J/kg
Mixed-layer CIN
-241 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
771 m above ground
0-6 km bulk shear
80 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
223 m²/s²
0-3 km storm-relative helicity
294 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

1.5 hours after it, 119 km from the path. March 1, 2017.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2017-03-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 23 joules per kilogram, CIN -97, lifted condensation level 1185 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 2017-03-01The 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 124 square meters per square second, 0 to 6 km bulk shear 46 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
23 J/kg
Mixed-layer CIN
-97 J/kg
Surface CAPE
2 J/kg
Mixed-layer LCL
1185 m above ground
0-6 km bulk shear
46 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
124 m²/s²
0-3 km storm-relative helicity
238 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4
0-3 km lapse rate
6.0 K/km

Open this sounding in Storm Lab

The surface observations

Peru (VYS), 8 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:00 UTC

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

This ground now

The live radar over the trackEvery 2017 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of February 28, 2017

29 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
February 283:53 PM CSTEF0Clinton, IA0.025
February 284:12 PM CSTEF1Stark, IL5.5100$100,000
February 284:41 PM CSTEF3LaSalle, IL11.5800214
February 284:44 PM CSTEF1Whiteside, IL2.675
February 284:58 PM CSTEF1LaSalle, IL2.8200
February 285:04 PM CSTEF0Grundy, IL1.2200
February 285:07 PM CSTEF1Ogle, IL1.550
February 285:10 PM CSTEF0Peoria, IL0.125
February 285:15 PM CSTEF0Peoria, IL0.9100$75,000
February 285:26 PM CSTEF3Marshall, IL17.8600$2.0 million
February 285:52 PM CSTEF2Livingston, IL5.675
February 286:40 PM CSTEF1Reynolds, MO4.480
February 287:03 PM CSTEF1White, AR1.41204$50,000
February 287:07 PM CSTEF2White, AR1.12501$70,000
February 287:16 PM CSTEF0Madison, MO4.450
February 287:51 PM CSTEF4Perryville tornado, Missouri and Illinois53.51,100112$15 million
February 288:54 PM ESTEF1Berrien, MI0.6100
February 288:58 PM ESTEF1Cass, MI5.0100
February 289:12 PM ESTEF1Cass, MI2.7150
February 289:38 PM ESTEF1Saint Joseph, MI2.050
February 289:33 PM CSTEF1Brown, IL0.7501
February 289:43 PM CSTEF1Bureau, IL2.350
February 289:55 PM CSTEF3White, IL to IN44.144012$5.7 million
February 2810:35 PM CSTEF0Calloway, KY8.830$70,000
February 2810:37 PM CSTEF0Crawford, KS0.175$50,000
February 2810:43 PM CSTEF0Crawford, KS0.175$10,000
February 2810:44 PM CSTEF1Williamson, IL7.425$6,000
February 2812:03 AM ESTEF2Dubois, IN5.8150$350,000
February 2811:28 PM CSTEF1Trigg, KY8.6400$300,000

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.