Tornadoes · United States · Illinois · 2020

EF0 tornado, Rohrer to New Berlin, Illinois, July 15, 2020

From Rohrer to New Berlin, this EF0 tornado ran 4.1 miles across Morgan and Sangamon counties on July 15, 2020, touching down at 4:28 PM CDT and reaching 50 yards wide. It killed nobody, and did $20,000 of property damage.

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 mphthis tornado

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

  2. EF186 to 110 mph

    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
EF0
Date
July 15, 2020
Touchdown
4:28 PM CDT (21:28 UTC)
Lifted
4:37 PM CDT (21:37 UTC)
On the ground
9 minutes
Path length
4.1 miles (6.7 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$20,000
Crop damage
$70,000
Counties
Morgan and Sangamon counties
Touchdown point
39.643, -89.968
Lift-off point
39.699, -89.943
Record number
2007151528-01

The damage survey

2 damage points were recorded along this path by NWS ILX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.

  • Start of tornado based on chaser report.

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 tracked from near Kansas City on the morning of July 15th to southern Lake Michigan by midnight on July 16th. The low interacted with an unstable and very moist environment to produce a Mesoscale Convective System (MCS) over eastern Kansas into Missouri, which then pushed into west-central Illinois by the mid to late morning of July 15th. Several rounds of convection moved across the Illinois River Valley through the afternoon, producing heavy rain and isolated wind damage. The heaviest rainfall of 5 to 7 inches was focused across Tazewell, Woodford, and far eastern Peoria counties where significant flash flooding occurred. In addition, 5 weak tornadoes touched down...including 2 in Tazewell County, 1 in McLean County, 1 in Morgan County, and 1 in Montgomery County which then crossed into southern Sangamon County. Minor damage was reported with some of the tornadoes: however, no injuries or deaths occurred.

A tornado touched down 3.5 miles north-northwest of Waverly at 4:28PM CDT. The tornado tracked north-northeastward and crossed into Sangamon County 4.5 miles north of Waverly at 4:30 PM CDT. Minor crop and tree damage was reported.

This tornado is a continuation of the tornado that touched down in Morgan County at 4:28 PM CDT. It crossed from Morgan County into Sangamon County 5.6 miles southwest of New Berlin at 4:30 PM CDT, then tracked north-northeastward and dissipated 2.5 miles southwest of New Berlin at 4:37 PM CDT. Minor crop and tree damage was reported.

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.

The county was under a tornado watch, issued at 19:11 UTC and running to 00:27 UTC.

Issued (UTC)ExpiredProductOffice
19:11 UTC00:27 UTCTornado WatchILX

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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:52 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

9.5 hours before the tornado, 127 km from the path. July 15, 2020.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2020-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -72859, lifted condensation level 1529 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Lincoln, IL at 12:00Z on 2020-07-15The 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 30 square meters per square second, 0 to 6 km bulk shear 20 knots.1939Sfc1 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
0 J/kg
Mixed-layer CIN
-72859 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1529 m above ground
0-6 km bulk shear
20 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
32 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.7 K/km

Open this sounding in Storm Lab

The surface observations

Jacksonville (IJX), 27 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:35 UTC8074.3160° 9 kt1011.5
19:55 UTC8274.7170° 10 kt181010.8
20:15 UTC82.275160° 14 kt181010.8
20:35 UTC8275.4180° 9 kt1010.5TS
20:55 UTC82.876180° 8 kt1009.8VCTS
21:15 UTC83.776.6180° 7 kt1009.1VCTS
21:35 UTC83.376.8160° 5 kt1008.8
21:55 UTC8276.8160° 7 kt1009.5VCTS
22:15 UTC77.274.3150° 9 kt1008.5-VCTSRA
22:35 UTC74.373.4270° 14 kt231010.5+TSRA
22:55 UTC72.372.3240° 7 kt111010.2-TSRA
23:15 UTC72.572.50° 0 kt1010.2VCTS

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

The radar

The Lincoln radar (KILX), 75 km away, was scanning. The volume nearest the touchdown began at 21:26 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
21:35 UTCTORNADO5 W LoamiSangamon, ILMINOR DAMAGE TO TREES.
21:47 UTCTORNADO4 Ese PalmyraMacoupin, ILTWO SPOTTERS REPORTED A TORNADO BRIEFLY TOUCHED DOWN IN A FIELD VERIFIED WITH A PICTURE. THIS TORNADO TOUCHED DOWN NORTHEAST OF HETTICK, IL, SOUTHWEST OF OTTER CREEK. THE TORNADO WAS VERY SHORT LIVED AND DID NOT DAMAGE A
22:20 UTCTORNADO4 N FarmersvilleMontgomery, ILA TORNADO DEVELOPED ABOUT 3 MILES NORTH-NORTHWEST OF FARMERSVILLE, ILLINOIS NEAR THE INTERSECTION OF ROVEY LANE AND EAST 1ST ROAD. A FEW STORM CHASERS CAPTURED VIDEO OF THE TORNADO AS IT MOVED NORTHEAST AND THEN NORTH TO
23:30 UTCHEAVY RAIN 1.1JacksonvilleMorgan, ILREPORTED IN 25 MINUTES
00:00 UTCHEAVY RAIN 2.714 W SpringfieldSangamon, IL

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 IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

The other tornadoes of July 15, 2020

9 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 151:37 PM CDTUnratedTazewell, IL0.110
July 151:45 PM CDTUnratedTazewell, IL0.110
July 154:04 PM CDTUnratedMcLean, IL0.210
July 154:47 PM CDTUnratedMacoupin, IL0.115
July 154:58 PM CDTEF0Montgomery, IL3.275
July 155:05 PM CDTEF0Montgomery, IL0.650
July 155:18 PM CDTEF0Sangamon, IL4.5300
July 156:03 PM MDTEF0Socorro, NM0.330
July 1511:40 PM CDTEF1Posey, IN4.380$95,000

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.