EF1 tornado, Boskydell to Creal Spgs, Illinois, May 8, 2024

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

May 8, 2024

Touchdown

3:10 PM CDT (20:10 UTC)

Lifted

3:26 PM CDT (20:26 UTC)

On the ground

16 minutes

Path length

4.6 miles (7.3 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

0

Property damage

$12,000

Counties

Jackson and Williamson counties

Touchdown point

37.665, -89.174

Lift-off point

37.669, -89.091

Record number

2405081410-01

23 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 90 mph.

• Diseased ash tree partially uprooted and snapped at the base.
• Pine tree leaning on power pole. Several small limbs down as well.
• One large 6-8 inch limb snapped.

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

A major outbreak of severe weather occurred on the 8th for the Quad State region. On the synoptic scale, a longwave trough was centered across the Rockies with deep-layer southwesterly flow from the Southern Plains to the Ohio Valley. A 110 kt upper jet extended from northern KS to IA while a 60 kt mid-level jet was positioned across northern MZ into IA. Surface low pressure near the MZ/KS border lifted to St. Louis around 12am CST on the 9th. A warm frontal boundary stretched across the Quad State, with a cold front extending southward from the surface low. ||The environment became unstable by early afternoon, especially in far Southern Illinois, with MLCAPE of 2000-3000 J/kg. Deep-layer shear was on the order of 55-65 kts, though low-level shear was 15 kts, increasing to 20 kts later in the day. SRH was around 100-150 m2/s2 with higher values north towards St. Louis. STP values were 2-4 due to deep-layer shear and instability. Supercell activity was more prominent during the afternoon in Southern Illinois with lapse rates of 6.5-7 C/km aiding with hail production.||For Southern Illinois, storms moved through with the cold front late evening on the 7th through the overnight hours with tree and power line damage in Joppa. The front reversed and lifted north during the morning, with storms entering Southwest Illinois late morning. A brief EF-1 tornado in Cora damaged trees and a few homes while injuring one person due to a falling tree limb. The afternoon brought a significant ramping up of supercell development and the arrival of a line of storms from the west. An EF-0 tornado crossed from Jackson County into Williamson County. An EF-0 tornado went through central subdivisions of the Lake of Egypt community, while an EF-1 tornado progressed eastward in Saline County with a broader area of straight-line wind damage around it. An initial evening round of storms swept through the northern half of Southern Illinois with wind damage most prominent in northern Wayne County with a swath of 75 to 85 mph straight-line wind damage and an embedded downburst.||Training heavy rainfall during the afternoon produced flash flooding from Jackson County eastward with rainfall totals commonly in the 2.5-4 inch range for northern Jackson, Williamson, Saline, Gallatin, and northern Union County. Hardest hit by flooding were Eldorado and Harrisburg in Saline County which received 1.5-2 inches within an hour. In Eldorado, Ferrell Hospital had floodwaters intrude on 55,000 sq ft of hospital space, necessitating transfer of patients. The high school had water in the entrance areas, and numerous roads flooded. Harrisburg avoided some of the higher end impacts of Eldorado but had many roads flooded for much of the afternoon and evening.

An EF-1 tornado (max of EF-0 in Jackson County) began southeast of Carbondale at Giant City Rd. Several large tree limbs were downed on Wagon Wheel Road and County Line Rd as the tornado crossed into Williamson County. Peak winds for the Jackson County portion of this tornado were estimated at 80 mph.

An EF-1 tornado entered into Williamson County from Jackson County at S. County Line Rd. Damage was primarily to tree limbs along a path continuing eastward. A large tree was uprooted on Skyhawk Road. Moving east, a barn suffered roof damage on New Hope Road. The tornado lifted after crossing Spillway Road on the southwest side of Crab Orchard National Wildlife Refuge. Video of this tornado was shared on social media. Peak winds for the Williamson County portion of this tornado, and for the tornado as a whole, were estimated at 90 mph.

An EF-0 tornado did intermittent damage from the central subdivisions of the Lake of Egypt community to just south of Creal Springs in Williamson County, IL. The great majority of the damage was from downed tree limbs. A couple trees in waterlogged soil were also uprooted. Peak winds from this tornado were estimated at 80 mph.

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

8 minutes of warning. NWS PAH issued a tornado warning for this county at 20:02 UTC, 8 minutes before the tornado touched down, in force until 20:30 UTC.

The county was under a tornado watch, issued at 15:29 UTC and running to 23:52 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 Moderate Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:32 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.

Marion Regional (MWA), 14 km from the path, in the two hours either side.

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

The Paducah radar (KPAH), 74 km away, was scanning. The volume nearest the touchdown began at 20:08 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 2024 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

52 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.