Tornadoes · United States · Wisconsin · 2020
EF0 tornado, Rouse, Wisconsin, September 25, 2020
This EF0 tornado ran 0.8 miles across Iron County on September 25, 2020, touching down at 7:52 PM CDT 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.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- September 25, 2020
- Touchdown
- 7:52 PM CDT (00:52 UTC)
- Lifted
- 7:54 PM CDT (00:54 UTC)
- On the ground
- 2 minutes
- Path length
- 0.8 miles (1.3 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- County
- Iron County
- Touchdown point
- 46.340, -90.450
- Lift-off point
- 46.340, -90.440
- Record number
- 2009251852-01
The damage survey
1 damage points were recorded along this path by NWS DLH, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.
- Numerous trees reported downed across a swath of land on Caroline Lake Road.
Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.
What the Weather Service recorded
A strong, late season cold front worked through the Northland on the evening of the 25th. Ample shear was in place along with cold air aloft to lead to the development of storms that were efficient hail producers across parts of northwest Wisconsin. One of the storms was able to tap into the strong shear and produce a brief, weak tornado that produced tree damage near Upson.
A brief, weak tornado caused tree damage across mainly county-owned forested land southwest of Upson.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 23:53 UTC | 00:45 UTC | Severe Thunderstorm Warning | DLH |
| 00:26 UTC | 00:48 UTC | Tornado Warning | DLH |
| 00:48 UTC | 01:30 UTC | Severe Thunderstorm Warning | DLH |
| 01:25 UTC | 02:15 UTC | Severe Thunderstorm Warning | DLH |
| 02:14 UTC | 02:50 UTC | Severe Thunderstorm Warning | DLH |
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, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:40 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.
Green Bay/Straub, WI (KGRB), 00:00Z
0.9 hours before the tornado, 276 km from the path. September 26, 2020.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -81640 J/kg
- Surface CAPE
- 16 J/kg
- Mixed-layer LCL
- 1640 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 107 m²/s²
- 0-3 km storm-relative helicity
- 220 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.7 K/km
Green Bay/Straub, WI (KGRB), 12:00Z
11.1 hours after it, 276 km from the path. September 26, 2020.
- Mixed-layer CAPE
- 87 J/kg
- Mixed-layer CIN
- -480 J/kg
- Surface CAPE
- 8 J/kg
- Mixed-layer LCL
- 1032 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 108 m²/s²
- 0-3 km storm-relative helicity
- 116 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.9 K/km
The surface observations
Ironwood (IWD), 32 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 22:55 UTC | 210° 8 kt | 1003.7 | ||||
| 22:56 UTC | 72 | 64 | 220° 8 kt | 1003.7 | ||
| 23:00 UTC | 220° 5 kt | 1003.7 | ||||
| 23:05 UTC | 200° 5 kt | 1003.7 | ||||
| 23:10 UTC | 210° 5 kt | 1003.7 | ||||
| 23:15 UTC | 240° 5 kt | 1004.1 | ||||
| 23:20 UTC | 71.6 | 64.4 | 240° 6 kt | 1004.1 | -TSRA | |
| 23:25 UTC | 220° 4 kt | 1003.7 | +RA | |||
| 23:30 UTC | 200° 5 kt | 1003.4 | RA | |||
| 23:35 UTC | 210° 5 kt | 1003 | -RA | |||
| 23:40 UTC | 270° 7 kt | 1003 | -RA | |||
| 23:41 UTC | 68 | 64.4 | 280° 9 kt | 1003 | -RA | |
| 23:45 UTC | 300° 9 kt | 1002.7 | -RA | |||
| 23:50 UTC | 300° 5 kt | 1002.7 | ||||
| 23:55 UTC | 310° 5 kt | 1002.7 | ||||
| 23:56 UTC | 64 | 62 | 310° 4 kt | 1002.7 | ||
| 00:00 UTC | 340° 5 kt | 1002.7 | ||||
| 00:05 UTC | 330° 5 kt | 1002.7 | ||||
| 00:07 UTC | 60.8 | 60.8 | 330° 5 kt | 1002.7 | ||
| 00:10 UTC | 320° 8 kt | 1003 | ||||
| 00:15 UTC | 330° 2 kt | 1003 | ||||
| 00:20 UTC | 0° 0 kt | 1002.4 | ||||
| 00:30 UTC | 0° 0 kt | 1002.4 | ||||
| 00:35 UTC | 360° 5 kt | 1002.7 | ||||
| 00:38 UTC | 60.8 | 59 | 360° 7 kt | 1003.4 | ||
| 00:40 UTC | 360° 8 kt | 1003 | ||||
| 00:45 UTC | 350° 5 kt | 1003.7 | ||||
| 00:50 UTC | 330° 7 kt | 1003.7 | -RA | |||
| 00:55 UTC | 33 | 1004.4 | RA | |||
| 00:56 UTC | 58 | 57 | 320° 28 kt | 33 | 1004.7 | VCTS +RA |
| 01:00 UTC | 19 kt | 1006.1 | +RA BR | |||
| 01:05 UTC | 15 kt | 21 | 1006.1 | +RA BR | ||
| 01:10 UTC | 9 kt | 1006.1 | +RA BR | |||
| 01:13 UTC | 57.2 | 55.4 | 30° 14 kt | 23 | 1005.4 | VCTS +RA BR |
| 01:15 UTC | 15 kt | 21 | 1005.1 | RA BR | ||
| 01:20 UTC | 11 kt | 1005.4 | RA | |||
| 01:24 UTC | 57.2 | 55.4 | 50° 9 kt | 22 | 1005.4 | VCTS -RA |
| 01:25 UTC | 10 kt | 17 | 1005.4 | -RA | ||
| 01:30 UTC | 40° 10 kt | 1005.4 | -RA | |||
| 01:35 UTC | 10° 5 kt | 1006.4 | RA | |||
| 01:40 UTC | 80° 8 kt | 1005.8 | RA | |||
| 01:41 UTC | 55.4 | 55.4 | 80° 8 kt | 1005.8 | VCTS RA | |
| 01:45 UTC | 100° 7 kt | 1006.1 | RA | |||
| 01:50 UTC | 80° 7 kt | 1006.1 | +RA | |||
| 01:55 UTC | 100° 5 kt | 1006.4 | -RA | |||
| 01:56 UTC | 57 | 56 | 100° 6 kt | 1006.4 | -TSRA | |
| 02:00 UTC | 110° 5 kt | 1006.4 | -RA | |||
| 02:04 UTC | 57.2 | 55.4 | 130° 8 kt | 1006.4 | VCTS -RA | |
| 02:05 UTC | 130° 8 kt | 1006.4 | -RA | |||
| 02:10 UTC | 90° 5 kt | 1006.1 | +RA BR | |||
| 02:14 UTC | 57.2 | 55.4 | 110° 6 kt | 1006.1 | -RA BR | |
| 02:15 UTC | 120° 8 kt | 1006.1 | -RA BR | |||
| 02:20 UTC | 110° 8 kt | 1006.1 | -RA | |||
| 02:25 UTC | 110° 8 kt | 1006.1 | -RA | |||
| 02:30 UTC | 120° 8 kt | 1006.1 | -RA | |||
| 02:35 UTC | 110° 7 kt | 1006.1 | ||||
| 02:40 UTC | 120° 8 kt | 1006.1 | ||||
| 02:45 UTC | 100° 5 kt | 1005.8 | ||||
| 02:50 UTC | 110° 7 kt | 1005.8 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Duluth radar (KDLH), 146 km away, was scanning. The volume nearest the touchdown began at 00:51 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.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 00:11 UTC | HAIL 0.25 | 1 Nnw Sanborn | Ashland, WI | |
| 00:50 UTC | HAIL 0.7 | Mellen | Ashland, WI | |
| 00:51 UTC | TSTM WND DMG | 3 Sw Upson | Iron, WI | DELAYED REPORT. NUMEROUS TREES DOWN AND TANGLED. TIME ESTIMATED FROM RADAR DATA. |
| 00:51 UTC | TORNADO | 3 Sw Upson | Iron, WI | EMERGENCY MANAGEMENT CONFIRMED TORNADO-LIKE DAMAGE ACROSS A FEW ACRES. TORNADO DAMAGE RATING NOT YET KNOWN PENDING ADDITIONAL INFORMATION. TIME ESTIMATED FROM RADAR DATA. |
| 00:52 UTC | TORNADO | 3 Sw Upson | Iron, WI | A BRIEF, WEAK TORNADO CAUSED TREE DAMAGE ACROSS MAINLY COUNTY-OWNED FORESTED LAND SOUTHWEST OF UPSON. |
| 00:55 UTC | HAIL 1 | Upson | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM UPSON. HAIL OCCURRED OVER A 15 MINUTE PERIOD THROUGH 8 PM. |
| 00:55 UTC | HAIL 2 | 3 Nw Morse | Ashland, WI | |
| 01:00 UTC | TSTM WND DMG | 3 S Mellen | Ashland, WI | TREE DOWN ON HIGHWAY 77. |
| 01:00 UTC | HAIL 1 | Upson | Iron, WI | |
| 01:48 UTC | HAIL 0.75 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: DIME (0.75 IN.). |
| 01:48 UTC | HAIL 0.75 | Mercer | Iron, WI | REPORT FROM MPING: DIME (0.75 IN.). |
| 01:51 UTC | HAIL 0.7 | 2 Ene Mercer | Iron, WI | |
| 02:00 UTC | HAIL 0.5 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: HALF-INCH (0.50 IN.). |
| 02:00 UTC | HAIL 0.5 | Mercer | Iron, WI | REPORT FROM MPING: HALF-INCH (0.50 IN.). |
| 02:01 UTC | HAIL 0.75 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: DIME (0.75 IN.). |
| 02:01 UTC | HAIL 0.75 | Mercer | Iron, WI | REPORT FROM MPING: DIME (0.75 IN.). |
| 02:02 UTC | HAIL 0.75 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: DIME (0.75 IN.). |
| 02:02 UTC | HAIL 0.75 | Mercer | Iron, WI | REPORT FROM MPING: DIME (0.75 IN.). |
| 02:03 UTC | HAIL 0.75 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: DIME (0.75 IN.). |
| 02:03 UTC | HAIL 0.75 | Mercer | Iron, WI | REPORT FROM MPING: DIME (0.75 IN.). |
| 02:03 UTC | HAIL 1 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: QUARTER (1.00 IN.). |
| 02:03 UTC | HAIL 1 | Mercer | Iron, WI | REPORT FROM MPING: QUARTER (1.00 IN.). |
| 02:04 UTC | HAIL 1.25 | Mercer | Iron, WI | REPORT FROM MPING: HALF DOLLAR (1.25 IN.). |
| 02:05 UTC | HAIL 1.25 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: HALF DOLLAR (1.25 IN.). |
| 02:05 UTC | HAIL 1.25 | Mercer | Iron, WI | REPORT FROM MPING: HALF DOLLAR (1.25 IN.). |
| 02:06 UTC | HAIL 1.25 | Mercer | Iron, WI | |
| 02:09 UTC | HAIL 0.7 | 1 S Mercer | Iron, WI | |
| 02:10 UTC | HAIL 1 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: QUARTER (1.00 IN.). |
| 02:10 UTC | HAIL 1 | Mercer | Iron, WI | REPORT FROM MPING: QUARTER (1.00 IN.). |
| 02:10 UTC | TSTM WND DMG | Presque Isle | Vilas, WI | NUMEROUS TREES DOWN AROUND THE TOWN AND COUNTY ROAD W |
| 02:12 UTC | HAIL 0.75 | Mercer | Iron, WI | CORRECTS PREVIOUS HAIL REPORT FROM MERCER. REPORT FROM MPING: DIME (0.75 IN.). |
| 02:12 UTC | HAIL 0.75 | Mercer | Iron, WI | REPORT FROM MPING: DIME (0.75 IN.). |
| 02:15 UTC | HAIL 0.7 | 2 Ene Mercer | Iron, WI |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2020 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are
The other tornadoes of September 25, 2020
1 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| September 25 | 3:24 PM EDT | EF0 | Horry, SC | 0.2 | 25 | $3,000 |
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.