Tornadoes · United States · Illinois · 1998

F1 tornado, Granite City to Edwardsville, Illinois, April 13, 1998

From Granite City to Edwardsville, this F1 tornado ran 9.5 miles across Madison County on April 13, 1998, touching down at 6:05 PM CDT and reaching 80 yards wide. It killed nobody, and did $800,000 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 mph

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

  2. F173 to 112 mphthis tornado

    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
F1
Date
April 13, 1998
Touchdown
6:05 PM CDT (23:05 UTC)
Path length
9.5 miles (15.3 km)
Path width
80 yards (73 m)
Deaths
0
Injuries
0
Property damage
$800,000
County
Madison County
Touchdown point
38.720, -90.130
Lift-off point
38.820, -89.950
Record number
103

What the Weather Service recorded

The same thunderstorm that produced a tornado in St. Louis County produced another in Madison County from Granite City to Edwardsville. The tornado first caused damage on the northwest side of Granite City at the Nameoki Trailer Park where 5 mobile homes were damaged by downed trees. The tornado moved northeast to Pontoon Beach where about 6 homes suffered roof damage. The tornado weakened, but gained strength again and caused damage on the south side of Edwardsville, primarily at the intersection of Center Grove, Goshen, and Troy roads. Several businesses suffered roof damage in this area, among them a floor covering store, an autobody shop, and the Moose Lodge. A nearby daycare also suffered minor roof damage.

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

The warnings

29 minutes of warning. NWS LSX issued a tornado warning for this county at 22:36 UTC, 29 minutes before the tornado touched down, in force until 23:30 UTC.

Issued (UTC)ExpiredProductOffice
22:36 UTC23:30 UTCTornado WarningLSX
23:04 UTC23:45 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 10:34 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

11.1 hours before the tornado, 197 km from the path. April 13, 1998.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 1998-04-13Temperature 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 -89992, lifted condensation level 1703 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, Lincoln, IL at 12:00Z on 1998-04-13The 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 337 square meters per square second, 0 to 6 km bulk shear 47 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
-89992 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1703 m above ground
0-6 km bulk shear
47 kt
0-1 km bulk shear
35 kt
0-1 km storm-relative helicity
337 m²/s²
0-3 km storm-relative helicity
313 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

0.9 hours after it, 197 km from the path. April 14, 1998.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 1998-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 406 joules per kilogram, CIN 0, lifted condensation level 531 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 00:00Z on 1998-04-14The 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 172 square meters per square second, 0 to 6 km bulk shear 27 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
406 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
280 J/kg
Mixed-layer LCL
531 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
224 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.3 K/km

Open this sounding in Storm Lab

The surface observations

Alton/St Louis R (ALN), 13 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
21:45 UTC64.460.8170° 20 kt261001.4
22:20 UTC64.460.8140° 20 kt261001
22:45 UTC62.660.8140° 12 kt261001.4
23:45 UTC60.860.8170° 8 kt1001.7
00:45 UTC60.859250° 12 kt1003

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

The radar

The St Louis radar (KLSX), 56 km away, was scanning. The volume nearest the touchdown began at 23:06 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 1998 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of April 13, 1998

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 132:40 PM CDTF1Callaway, MO0.570$50,000
April 133:20 PM CDTF0Montgomery, MO0.250
April 134:09 PM CDTF0Warren, MO18.050$1,000
April 135:26 PM CDTF1Sainte Genevieve, MO0.280$60,000
April 135:35 PM CDTF1Saint Louis, MO3.01001$2.5 million
April 139:09 PM CDTF1Johnson, IL1.0401$60,000
April 1311:13 PM CDTF1Graves, KY7.0100$200,000

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.