EF2 tornado, Wilton to Frankfort Arpt, Illinois, November 17, 2013

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 mph

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

3. EF2111 to 135 mphthis tornado

   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.

Rating

EF2

Date

November 17, 2013

Touchdown

12:42 PM CST (18:42 UTC)

Lifted

12:48 PM CST (18:48 UTC)

On the ground

6 minutes

Path length

5.2 miles (8.4 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$750,000

County

Will County

Touchdown point

41.409, -87.931

Lift-off point

41.469, -87.870

Record number

1311171242-01

7 damage points were recorded along this path by NWS LOT, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 125 mph.

• Tornado lifted in Midewin field.
• Damage consistent among metal building and trees next door. Damage tossed 300-500 yards to the northeast.
• Minor tree damage. Tornado appeared to lift.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A major tornado outbreak impacted the Midwest and Ohio Valley on November 17th. A powerful low pressure system across the plains states steered warmth and moisture northward for nearly two days, with dew points rising into the mid 60's. This coupled with temperatures around 70�� resulted in unseasonably strong instability for thunderstorms to develop. High wind shear and a cold front sweeping eastward made up the remaining ingredients of an environment favorable for supercells capable of long-lived significant tornadoes. Within the WFO LOT county warning area, ten tornadoes were confirmed, including three EF-2 tornadoes. As the event evolved, the system became linear with numerous reports of straight line wind damage. Behind the thunderstorms, a wake low developed with wind gusts to around 60 mph.

The tornado touched down south of W Bruns Road and east of S Kankakee Street. This tornado quickly intensified to EF-2 damaging five houses along Bruns Road rendering them uninhabitable by removing large sections of the roofs and leading to partial wall collapse. Four high tension power line towers were bent along S Schoolhouse Road. Two houses and a barn were heavily damaged on W Dralle Road where large portions of the roofs were ripped off. Several trees were snapped and uprooted as well. Another farm on S Scheer Road had roof damage consistent to EF-1 intensity. The last sign of damage occurred just south of Steger Road where large branches were blown down. Maximum winds were estimated to around 125 mph.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

28 minutes of warning. NWS LOT issued a tornado warning for this county at 18:14 UTC, 28 minutes before the tornado touched down, in force until 19:00 UTC.

The county was under a tornado watch, issued at 14:40 UTC and running to 19:45 UTC.

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 Storm Prediction Center had this point in a High Risk, with a 0.30 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 16:30 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 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.

The Chicago radar (KLOT), 24 km away, was scanning. The volume nearest the touchdown began at 18:40 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.

Local storm reports within 60 km of the path, in the three hours either side.

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

The live radar over the trackEvery 2013 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

75 more were confirmed in the United States that day.

All 76 of them

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.