Tornadoes · United States · Wisconsin · 1999
F1 tornado, Mondovi, Wisconsin, July 8, 1999
This F1 tornado ran 10.0 miles across Buffalo County on July 8, 1999, touching down at 6:20 PM CDT and reaching 120 yards wide. It killed nobody and injured 3, and did $1.0 million 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.
F040 to 72 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mphthis tornado
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
- F1
- Date
- July 8, 1999
- Touchdown
- 6:20 PM CDT (23:20 UTC)
- Path length
- 10.0 miles (16.1 km)
- Path width
- 120 yards (110 m)
- Deaths
- 0
- Injuries
- 3
- Property damage
- $1.0 million
- County
- Buffalo County
- Touchdown point
- 44.480, -91.800
- Lift-off point
- 44.580, -91.650
- Record number
- 542
What the Weather Service recorded
A tornado sheared off trees and caused minor damage to homes and barns before hitting the town of Mondovi (Buffalo County). Two homes in Mondovi had roofs removed or garages damaged. Three people sustained minor injuries. 70 to 80 mph winds ripped through areas east of La Crosse, knocking down numerous trees and causing extensive damage to a campground. One home and a barn were destroyed, while a few other homes received roof damage. Several cars were crushed or damaged by falling limbs and trees. There were no injuries reported. Elsewhere across west central Wisconsin, damaging winds and dime size hail were reported by spotters and law enforcement officials.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
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.
Minneapolis, MN (KMPX), 12:00Z
11.3 hours before the tornado, 152 km from the path. July 8, 1999.
- Mixed-layer CAPE
- 8 J/kg
- Mixed-layer CIN
- -308 J/kg
- Surface CAPE
- 29 J/kg
- Mixed-layer LCL
- 1425 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
- 0-3 km lapse rate
- 4.4 K/km
Minneapolis, MN (KMPX), 00:00Z
0.7 hours after it, 152 km from the path. July 9, 1999.
- Mixed-layer CAPE
- 2575 J/kg
- Mixed-layer CIN
- -33 J/kg
- Surface CAPE
- 4935 J/kg
- Mixed-layer LCL
- 1341 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 157 m²/s²
- 0-3 km storm-relative helicity
- 115 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 15.1
- 0-3 km lapse rate
- 6.2 K/km
The surface observations
Eau Claire (EAU), 42 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 00:00 UTC |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The La Crosse radar (KARX), 89 km away, was scanning. The volume nearest the touchdown began at 23:20 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 WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are
The other tornadoes of July 8, 1999
1 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| July 8 | 7:20 PM CDT | F2 | Winona, MN | 3.5 | 100 | 2 | $2.0 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.