EF1 tornado, Carterville, Illinois, April 5, 2017

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.

Rating

EF1

Date

April 5, 2017

Touchdown

2:10 PM CDT (19:10 UTC)

Lifted

2:11 PM CDT (19:11 UTC)

On the ground

1 minutes

Path length

0.1 miles (0.2 km)

Path width

25 yards (23 m)

Deaths

0

Injuries

0

Property damage

$35,000

County

Williamson County

Touchdown point

37.700, -89.149

Lift-off point

37.700, -89.147

Record number

1704051310-01

2 damage points were recorded along this path by NWS PAH, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 105 mph.

• witnesses. saw rotation move through the yard. took a tree and impaled it into the house. loss of Coopala on the top of the house and the back 1/3 of the house. debris thrown several hundred yards and insulation in trees. very brief touchdown likely.
• mainly shingle damage. tree in front yard-Bradford Pear snapped. and thrown across the road.

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

Scattered storms increased during the afternoon as solar heating destabilized the atmosphere. A surface low pressure center between St. Louis, MO and Quincy, IL tracked east-northeastward during the afternoon. Storms increased along and near a warm front that extended east-southeast from the low into southeast Illinois. Surface dew points in the 50's spread northeastward beneath cold mid-level temperatures aloft. The atmosphere became sufficiently unstable for severe storms, with capes approaching 1000 j/kg. Wind fields aloft were quite strong as a belt of 80-knot winds at 500 mb progressed northeast into the Tennessee Valley. The strong wind shear facilitated several severe storms, including a brief tornado.

A brief EF-1 tornado touched down, damaging two residences and taking down a few trees. The first residence received minor shingle damage, and there was substantial roof damage at the second residence. Insulation and building debris was blown several hundred yards. The small tornado was captured on security camera video at a very close distance, less than 50 yards away. Peak winds were estimated near 105 mph. A trained spotter reported a rotating wall cloud south of Carbondale shortly before the tornado occurred.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

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 Marginal Risk. The outlook in force was issued at 16:29 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.

Carbondale/Murph (MDH), 13 km from the path, in the two hours either side.

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

The Paducah radar (KPAH), 78 km away, was scanning. The volume nearest the touchdown began at 19:10 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 2017 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

23 more were confirmed in the United States that day.

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.