Tornadoes · United States · Illinois · 2015

EF1 tornado, Gingle Corners to Preemption, Illinois, June 11, 2015

From Gingle Corners to Preemption, this EF1 tornado ran 5.9 miles across Mercer County on June 11, 2015, touching down at 5:25 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.

  1. EF065 to 85 mph

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

  2. EF186 to 110 mphthis tornado

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. 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.

  4. 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.

  5. EF4166 to 200 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. 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.

  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
EF1
Date
June 11, 2015
Touchdown
5:25 PM CDT (22:25 UTC)
Lifted
5:37 PM CDT (22:37 UTC)
On the ground
12 minutes
Path length
5.9 miles (9.6 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Crop damage
$10,000
County
Mercer County
Touchdown point
41.266, -90.708
Lift-off point
41.314, -90.613
Record number
1506111625-01

The damage survey

7 damage points were recorded along this path by NWS DVN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 100 mph.

  • corn blown over. apparent tornado end
  • Apparent tornado beginning

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

Low pressure moved east over Iowa and Illinois the afternoon of June 11th, which brought widespread thunderstorms with heavy rain and flash flooding to Iowa, Illinois, and northern Missouri. A tornado occurred in northwest Illinois during the evening hours June 11, 2015. A rotating storm brought a tornado to portion of Mercer County Illinois.

A tornado touched down 5.3 miles west of Matherville in Mercer County, and damaged mainly trees and some crops before lifting 3.5 miles north of Matherville. The tornado was on the ground for approximately 6 miles and produced EF1 damage from 100 mph winds, evidenced by snapping of hardwood tree trunks.

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)ExpiredProductOffice
16:00 UTC10:04 UTCFlash Flood WatchDVN
22:32 UTC22:52 UTCTornado WarningDVN

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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 20:01 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.

Davenport, (KDVN), 12:00Z

10.4 hours before the tornado, 39 km from the path. June 11, 2015.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2015-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 20 joules per kilogram, CIN -459, lifted condensation level 1808 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, Davenport, at 12:00Z on 2015-06-11The 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 197 square meters per square second, 0 to 6 km bulk shear 34 knots.193958Sfc1 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
20 J/kg
Mixed-layer CIN
-459 J/kg
Surface CAPE
176 J/kg
Mixed-layer LCL
1808 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
197 m²/s²
0-3 km storm-relative helicity
190 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.1 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

1.6 hours after it, 39 km from the path. June 12, 2015.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2015-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 77 joules per kilogram, CIN -83, lifted condensation level 1037 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, Davenport, at 00:00Z on 2015-06-12The 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 192 square meters per square second, 0 to 6 km bulk shear 28 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
77 J/kg
Mixed-layer CIN
-83 J/kg
Surface CAPE
88 J/kg
Mixed-layer LCL
1037 m above ground
0-6 km bulk shear
28 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
192 m²/s²
0-3 km storm-relative helicity
344 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
5.1 K/km

Open this sounding in Storm Lab

The surface observations

Moline (MLI), 22 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:52 UTC807040° 4 kt1007.5
21:52 UTC797190° 6 kt1006.4
22:32 UTC777210° 3 kt1006.8VCTS -RA
22:39 UTC7773310° 7 kt1006.8TSRA BR
22:45 UTC7672270° 11 kt1007.1+TSRA BR
22:50 UTC75.271.6240° 16 kt21.971008.1TS +RA BR
22:52 UTC7572230° 18 kt241007.8+TSRA FG
22:55 UTC7471220° 15 kt241008.1+TSRA FG
23:05 UTC7269120° 7 kt1007.1+TSRA BR
23:07 UTC7369 3 kt1007.1TSRA BR
23:32 UTC736870° 8 kt1006.8HZ
23:52 UTC726870° 9 kt1006.8BR
23:59 UTC726870° 6 kt1006.8-TSRA
00:13 UTC72680° 0 kt1007.1+TSRA BR
00:17 UTC72690° 0 kt1007.5+TSRA BR
00:23 UTC7169 5 kt1007.5+TSRA FG

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

The radar

The Quad Cities radar (KDVN), 36 km away, was scanning. The volume nearest the touchdown began at 22:26 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)ReportWhereCountyRemark
22:25 UTCTORNADO5 Nne AledoMercer, ILCONFIRMED EF1 TORNADO...DEVELOPED 5 NNE OF ALEDO OR 5.3 W OF MATHERVILLE...PEAK WINDS 100 MPH...PATH LENGTH 6 MILES...PATH WIDTH 50 YARDS. THIS TORNADO CAUSED THE DAMAGE DESCRIBED IN THE 2 SSE REYNOLDS STORM REPORT ISSUE
22:31 UTCTORNADO2 Sse ReynoldsMercer, ILTREES AND POWERLINES DOWN 1 MILE SOUTH OF 170TH AVE. RADAR CONFIRMED TORNADO DEBRIS SIGNATURE. PRELIMINARY REPORT...SURVEY TEAM WILL INVESTIGATE TOMORROW.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2015 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of June 11, 2015

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 114:00 PM CDTEF0Atchison, MO0.225
June 117:45 PM MDTEF0Baca, CO1.350

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.