Tornadoes · United States · Illinois · 1994

F0 tornado, Waterloo To 1 Ne Wate, Illinois, April 15, 1994

This F0 tornado ran 2.5 miles across Monroe County on April 15, 1994, touching down at 5:15 AM CDT and reaching 40 yards wide. It killed nobody, and did $50,000 to $500,000 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 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 15, 1994
Touchdown
5:15 AM CDT (10:15 UTC)
Path length
2.5 miles (4.0 km)
Path width
40 yards (37 m)
Deaths
0
Injuries
0
Property damage
$50,000 to $500,000
County
Monroe County
Touchdown point
38.350, -90.170
Record number
117

What the Weather Service recorded

A small tornado touched down in the northwest corner of Waterloo damaging a four-story brick grain elevator. Damage was generally confined to the building's roof (along the eastern side). As the tornado moved east-northeast through a residential area, damage was limited to large trees. A large cluster of trees were snapped off near the town high school in a rotational pattern. A house lost part of its roof northeast of Waterloo just before the tornado dissipated.

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

The warnings

11 minutes of warning. NWS LSX issued a tornado warning for this county at 10:04 UTC, 11 minutes before the tornado touched down, in force until 10:45 UTC.

Issued (UTC)ExpiredProductOffice
10:04 UTC10:45 UTCTornado WarningLSX

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. The outlook in force was issued at 07:12 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.

Paducah/Barkley, KY (KPAH), 00:00Z

10.3 hours before the tornado, 192 km from the path. April 15, 1994.

Skew-T log-pSkew-T log-p diagram, Paducah/Barkley, KY at 00:00Z on 1994-04-15Temperature 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 -43612, lifted condensation level 2422 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, Paducah/Barkley, KY at 00:00Z on 1994-04-15The 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 46 square meters per square second, 0 to 6 km bulk shear 25 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
-43612 J/kg
Surface CAPE
38 J/kg
Mixed-layer LCL
2422 m above ground
0-6 km bulk shear
25 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

Paducah/Barkley, KY (KPAH), 12:00Z

1.7 hours after it, 192 km from the path. April 15, 1994.

Skew-T log-pSkew-T log-p diagram, Paducah/Barkley, KY at 12:00Z on 1994-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2109 joules per kilogram, CIN -40, lifted condensation level 710 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, Paducah/Barkley, KY at 12:00Z on 1994-04-15The 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 280 square meters per square second, 0 to 6 km bulk shear 45 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
2109 J/kg
Mixed-layer CIN
-40 J/kg
Surface CAPE
2299 J/kg
Mixed-layer LCL
710 m above ground
0-6 km bulk shear
45 kt
0-1 km bulk shear
38 kt
0-1 km storm-relative helicity
280 m²/s²
0-3 km storm-relative helicity
287 m²/s²
Significant tornado parameter
3.2
Supercell composite
14.4
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

The surface observations

Cahokia/St Louis (CPS), 25 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
12:00 UTC250° 10 kt1007.1

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

The radar

The St Louis radar (KLSX), 59 km away, was scanning. The volume nearest the touchdown began at 10:17 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.

This ground now

The live radar over the trackEvery 1994 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of April 15, 1994

32 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 152:30 AM CDTF1Benton, MO7.0100$50,000 to $500,000
April 153:25 AM CDTF1Cole, MO25.070$50,000 to $500,000
April 153:45 AM CDTF0Pulaski, MO0.420$5,000 to $50,000
April 154:25 AM CDTF0Franklin, MO2.330$50,000 to $500,000
April 154:52 AM CDTF0Jefferson, MO4.050$50,000 to $500,000
April 155:05 AM CDTF0Jefferson, MO2.050$5,000 to $50,000
April 155:12 AM CDTF1Jefferson, MO2.3100$500,000 to $5 million
April 156:15 AM CDTF0Perry, MO0.323$5,000 to $50,000
April 156:22 AM CDTF1Fayette, IL2.560$50,000 to $500,000
April 157:36 AM ESTF1Lawrence, IN0.51002$50,000 to $500,000
April 157:46 AM ESTF1Lawrence, IN0.3303$5,000 to $50,000
April 158:04 AM ESTF1Greene, IN0.230$5,000 to $50,000
April 158:52 AM CDTF0Spencer, IN0.120
April 158:55 AM ESTF1Marion, IN0.280$500 to $5,000
April 1510:35 AM EDTF0Dearborn, IN0.120$500 to $5,000
April 1510:45 AM EDTF0Anderson, KY2.050$50,000 to $500,000
April 1510:45 AM EDTF0Franklin, KY0.150$5,000 to $50,000
April 1510:15 AM CDTF1Warren, KY0.130$50,000 to $500,000
April 1510:40 AM CDTF0Dunklin, MO0.320$50 to $500
April 1511:08 AM CDTF0Pemiscot, MO1.030
April 1512:15 PM EDTF1Scioto, OH0.230$50,000 to $500,000
April 1512:29 PM EDTF0Madison, KY1.050$50,000 to $500,000
April 1512:30 PM EDTF3Hamilton, TN15.088019$500,000 to $5 million
April 1512:30 PM EDTF0Carter, KY1.050$50,000 to $500,000
April 1512:45 PM EDTF0Jackson, OH0.120$5,000 to $50,000
April 1512:37 PM CDTF0Nacogdoches, TX0.110$500 to $5,000
April 154:55 PM CDTF0Madison, TX1.0100$5,000 to $50,000
April 154:56 PM CDTF2Harris, TX5.0300120$5,000 to $50,000
April 155:10 PM CDTF0Lincoln, MS0.540
April 156:24 PM CDTF0St. Clair, AL0.550$50,000 to $500,000
April 157:50 PM CDTF0Live Oak, TX0.110under $50
April 151:11 AM EDTF2Chester, SC3.07314$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.