Tornadoes · United States · Illinois · 1999
F0 tornado, Troy, Illinois, February 27, 1999
This F0 tornado ran 0.2 miles across Madison County on February 27, 1999, touching down at 12:05 PM CST and reaching 50 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.
F040 to 72 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- February 27, 1999
- Touchdown
- 12:05 PM CST (18:05 UTC)
- Path length
- 0.2 miles (0.3 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- County
- Madison County
- Touchdown point
- 38.750, -89.880
- Lift-off point
- 38.750, -89.880
- Record number
- 149
What the Weather Service recorded
Law enforcement and several spotters reported a small tornado just northwest of Troy near the intersection of I-270 and I-55/70. The tornado was brief, formed in an open field and did no damage.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
14 minutes of warning. NWS LSX issued a tornado warning for this county at 17:51 UTC, 14 minutes before the tornado touched down, in force until 18:40 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 17:34 UTC | 18:40 UTC | Severe Thunderstorm Warning | LSX |
| 17:51 UTC | 18:40 UTC | Tornado Warning | LSX |
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 16:00 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
6.1 hours before the tornado, 191 km from the path. February 27, 1999.
- Mixed-layer CAPE
- 107 J/kg
- Mixed-layer CIN
- -160 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 635 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 275 m²/s²
- 0-3 km storm-relative helicity
- 325 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.8 K/km
Lincoln, IL (KILX), 00:00Z
5.9 hours after it, 191 km from the path. February 28, 1999.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -46203 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 1538 m above ground
- 0-6 km bulk shear
- 71 kt
- 0-1 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -153 m²/s²
- 0-3 km storm-relative helicity
- -85 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.7 K/km
The radar
The St Louis radar (KLSX), 70 km away, was scanning. The volume nearest the touchdown began at 18:07 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 1999 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are
The other tornadoes of February 27, 1999
8 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| February 27 | 3:25 PM CST | F3 | Lawrence, MS | 17.0 | 440 | $200,000 | ||
| February 27 | 4:00 PM CST | F1 | Union, KY | 3.0 | 100 | 2 | $200,000 | |
| February 27 | 5:50 PM CST | F0 | Lawrence, MS | 1.0 | 50 | $30,000 | ||
| February 27 | 5:55 PM CST | F2 | Lauderdale, AL | 1.7 | 150 | $140,000 | ||
| February 27 | 6:25 PM CST | F0 | Winston, AL | 0.5 | 30 | $10,000 | ||
| February 27 | 7:15 PM CST | F2 | Blount, AL | 0.4 | 50 | 1 | $90,000 | |
| February 27 | 7:51 PM CST | F0 | Etowah, AL | 1.3 | 50 | $30,000 | ||
| February 27 | 11:00 PM CST | F1 | Saint Charles Parish, LA | 0.8 | 0 | $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.