Tornadoes · United States · Illinois · 2011
EF0 tornado, Okawville, Illinois, February 28, 2011
This EF0 tornado ran 2.8 miles across Washington County on February 28, 2011, touching down at 12:03 AM CST 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
- February 28, 2011
- Touchdown
- 12:03 AM CST (06:03 UTC)
- Lifted
- 12:06 AM CST (06:06 UTC)
- On the ground
- 3 minutes
- Path length
- 2.8 miles (4.5 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- County
- Washington County
- Touchdown point
- 38.423, -89.557
- Lift-off point
- 38.427, -89.507
- Record number
- 1102280003-01
What the Weather Service recorded
A quasi-stationary frontal boundary was the main focusing mechanism for a round of significant severe weather over the forecast area. A strong shortwave moved along the boundary triggering widespread showers and thunderstorms. Numerous reports of large hail, damaging winds and 22 tornadoes occurred with this system.
The tornado formed just to the southwest of Okawville. The tornado moved across the south side of town and damaged the local grain elevator, produced some minor roof and exterior damage to houses along the south side of East Schumacher Street. The Emmanuel Lutheran School also sustained some minor roof damage. The tornado continued to the east where it produced some additional damage and snapped an 8-10 inch diameter tree trunk approximately 6 feet off the ground. The tornado continued east until it damaged a house on Hummingbird Road. This house suffered an unknown amount of roof damage because it was in the process of being repaired. There was also minor tree damage and an outbuilding that was destroyed with the debris scattered several hundred yards to the northeast. The tornado lifted just to the east of this location. Path length was 2.8 miles with a maximum width of 50 yards and rated EF0.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
20 minutes of warning. NWS LSX issued a tornado warning for this county at 05:43 UTC, 20 minutes before the tornado touched down, in force until 06:30 UTC.
The county was under a tornado watch, issued at 03:40 UTC and running to 07:46 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 03:40 UTC | 07:46 UTC | Tornado Watch | LSX |
| 05:43 UTC | 06:30 UTC | Tornado Warning | LSX |
| 06:07 UTC | 06:28 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 05:58 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), 00:00Z
6.1 hours before the tornado, 208 km from the path. February 28, 2011.
- Mixed-layer CAPE
- 124 J/kg
- Mixed-layer CIN
- -220 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 494 m above ground
- 0-6 km bulk shear
- 76 kt
- 0-1 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 210 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
- 0-3 km lapse rate
- 3.7 K/km
Lincoln, IL (KILX), 12:00Z
5.9 hours after it, 208 km from the path. February 28, 2011.
- Mixed-layer CAPE
- 2 J/kg
- Mixed-layer CIN
- 0 J/kg
- Surface CAPE
- 5 J/kg
- Mixed-layer LCL
- 553 m above ground
- 0-6 km bulk shear
- 108 kt
- 0-1 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- -183 m²/s²
- 0-3 km storm-relative helicity
- 28 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 2.0 K/km
The radar
The St Louis radar (KLSX), 105 km away, was scanning. The volume nearest the touchdown began at 06:01 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 |
|---|---|---|---|---|
| 05:15 UTC | TSTM WND DMG | O'Fallon | St. Clair, IL | LARGE TREES DOWN...3-4FT IN DIAMETER. SOUTH HILL STREET |
| 05:33 UTC | TSTM WND GST 71 | Maryville | Madison, IL | |
| 05:35 UTC | TSTM WND DMG | 3 Ese Centreville | St. Clair, IL | EST. 70MPH WINDS... HALF INCH TREE LIMBS DOWN |
| 05:35 UTC | TSTM WND DMG | Granite City | Madison, IL | NUMEROUS TREES AND POWER LINES DOWN IN GRANITE CITY. SOME ROOF DAMAGE REPORTED. |
| 05:35 UTC | TSTM WND DMG | Highland | Madison, IL | MOST HOMES DAMAGED NEAR INTERSECTION OF 40 AND 143... HOLES IN SIDING... TREES BLOWN DOWN. |
| 05:40 UTC | TSTM WND DMG | Cahokia | St. Clair, IL | FENCE BROKEN IN HALF. FLAGPOLE BENT IN HALF. FLAGPOLE IS RATED TO 70 MPH. |
| 05:40 UTC | TSTM WND DMG | Edwardsville | Madison, IL | TREES DOWN |
| 05:40 UTC | TSTM WND DMG | Kuhn | Madison, IL | PARTS OF A BARN ROOF AND SIDING...A FLATTENED SHED...AND A VEHICLE 20 PLUS YARDS OFF THE ROADWAY OFF OF COUNTY ROAD 21 NEAR KUHN STATION ROAD. |
| 05:43 UTC | TSTM WND GST 60 | Collinsville | Madison, IL | |
| 05:44 UTC | TSTM WND GST 70 | East St. Louis | St. Clair, IL | |
| 05:45 UTC | TSTM WND DMG | Glen Carbon | Madison, IL | 6-8 INCH TREE LIMBS BLOWN DOWN |
| 05:45 UTC | TSTM WND DMG | Troy | Madison, IL | STRUCTURAL DAMAGE TO HOMES IN TROY |
| 05:50 UTC | TSTM WND DMG | 3 E Mascoutah | St. Clair, IL | TRACTOR TRAILER BLOWN OVER ON RTE 177 |
| 05:55 UTC | TSTM WND GST 55 | Mascoutah | St. Clair, IL | |
| 05:55 UTC | HAIL 0.25 | Mascoutah | St. Clair, IL | |
| 05:59 UTC | TSTM WND DMG | Highland | Madison, IL | POWER OUTAGES |
| 06:00 UTC | TSTM WND GST 59 | New Baden | Clinton, IL | |
| 06:00 UTC | TSTM WND GST 60 | Aviston | Clinton, IL | HEAVY LAWN FURNITURE BLOWN ACROSS YARD |
| 06:00 UTC | TSTM WND GST 61 | New Baden | Clinton, IL | |
| 06:02 UTC | TSTM WND GST 60 | Aviston | Clinton, IL | WIND GUSTS OF AT LEAST 60 MPH |
| 06:05 UTC | TSTM WND DMG | Okawville | Washington, IL | POWER POLES SNAPPED. EXTENSIVE DAMAGE TO A GRAIN ELEVATOR. METAL ROOFS BLOWN OFF OF SEVERAL BUILDINGS. |
| 06:10 UTC | TSTM WND DMG | Bartelso | Clinton, IL | BARN DESTROYED...POWER POLES SNAPPED. |
| 06:17 UTC | TSTM WND GST 50 | Sparta | Randolph, IL | |
| 06:18 UTC | TSTM WND GST 70 | Hoyleton | Washington, IL | HAM RADIO ANTENNAS BLOWN DOWN. |
| 06:30 UTC | TSTM WND DMG | 4 Se Walsh | Randolph, IL | A TREE WAS BLOWN DOWN ONTO ZION CHURCH ROAD SOUTHEAST OF WALSH. |
| 06:30 UTC | TSTM WND DMG | Central City | Marion, IL | POWER FLASHES SEEN...POWER LINES DOWN...MEDIUM SIZED LIMBS DOWN |
| 06:36 UTC | WALL CLOUD | Centralia | Marion, IL | ROTATING WALL CLOUD PASSED NORTH OF CENTRALIA IL. SPOTTER OBSERVED POWER FLASHES ON THE GROUND BUT COULD NOT SEE A FUNNEL CLOUD. |
| 06:41 UTC | HAIL 0.7 | Du Bois | Washington, IL | |
| 06:45 UTC | TSTM WND DMG | Mount Vernon | Jefferson, IL | ONE POWER POLE AND LINE DOWN IN TOWN. |
| 07:00 UTC | TSTM WND DMG | Greenville | Bond, IL | MOST OF TOWN IS WITHOUT POWER...SPORADIC POWER OUTAGES IN CENTRALIA AS WELL AS PARTS OF CLINTON AND WASHINGTON COUNTIES |
| 07:01 UTC | HAIL 0.75 | Mount Vernon | Jefferson, IL | DIME SIZE HAIL REPORTED AT INTERSECTION OF HWY 148 AND INTERSTATE 57. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2011 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are
The other tornadoes of February 28, 2011
25 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| February 28 | 12:08 AM CST | EF2 | Washington, IL | 2.3 | 100 | |||
| February 28 | 12:27 AM CST | EF2 | Fayette, IL | 1.3 | 90 | |||
| February 28 | 12:32 AM CST | EF1 | Fayette, IL | 0.1 | 10 | |||
| February 28 | 12:33 AM CST | EF2 | Fayette, IL | 0.1 | 50 | |||
| February 28 | 1:36 AM CST | EF1 | Gibson, IN | 23.3 | 250 | $150,000 | ||
| February 28 | 1:51 AM CST | EF2 | Gibson, IN | 22.0 | 550 | $600,000 | ||
| February 28 | 3:10 AM EST | EF0 | Pike, IN | 1.9 | 200 | $150,000 | ||
| February 28 | 3:19 AM EST | EF2 | Dubois, IN | 14.2 | 225 | 1 | $500,000 | |
| February 28 | 3:29 AM CST | EF1 | Clark, IN to KY | 3.0 | 100 | $7,000 | ||
| February 28 | 4:43 AM EST | EF1 | Oldham, KY | 1.2 | 75 | |||
| February 28 | 4:59 AM EST | EF3 | Henry, KY | 2.3 | 150 | 1 | $500,000 | |
| February 28 | 6:00 AM EST | EF1 | Fairfield, OH | 2.4 | 75 | $100,000 | ||
| February 28 | 6:49 AM EST | EF1 | Lincoln, KY | 8.7 | 250 | $100,000 | ||
| February 28 | 7:37 AM EST | EF1 | Wolfe, KY | 0.3 | 100 | $75,000 | ||
| February 28 | 12:18 PM CST | EF2 | Franklin, TN | 16.1 | 600 | 1 | 4 | $40,000 |
| February 28 | 12:18 PM CST | EF1 | Madison, AL | 3.9 | 200 | $30,000 | ||
| February 28 | 1:00 PM CST | EF0 | Marion, TN | 0.0 | 20 | $20,000 | ||
| February 28 | 2:25 PM EST | EF1 | Hamilton, TN | 2.2 | 90 | $1.3 million | ||
| February 28 | 2:30 PM EST | EF1 | Hamilton, TN | 2.6 | 150 | $5.0 million | ||
| February 28 | 3:53 PM CST | EF0 | Talladega, AL | 0.3 | 50 | $8,000 | ||
| February 28 | 5:02 PM EST | EF0 | Greenville, SC | 1.5 | 50 | |||
| February 28 | 5:05 PM CST | EF0 | Autauga, AL | 8.9 | 200 | $77,000 | ||
| February 28 | 5:28 PM CST | EF0 | Chambers, AL | 1.9 | 30 | $45,000 | ||
| February 28 | 5:37 PM CST | EF1 | Lowndes, AL | 5.0 | 200 | $60,000 | ||
| February 28 | 7:24 PM EST | EF1 | Newberry, SC | 3.4 | 100 | $120,000 |
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.