EF3 tornado, Palmer to Osbernville, Illinois, December 1, 2018

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 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 mphthis tornado

   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

EF3

Date

December 1, 2018

Touchdown

5:01 PM CST (23:01 UTC)

Lifted

5:25 PM CST (23:25 UTC)

On the ground

24 minutes

Path length

12.5 miles (20.1 km)

Path width

900 yards (823 m)

Deaths

0

Injuries

22

Property damage

$119 million

County

Christian County

Touchdown point

39.414, -89.395

Lift-off point

39.578, -89.298

Record number

1812011701-01

115 damage points were recorded along this path by NWS ILX and NWS LSX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF3. The highest wind the damage implies is 155 mph.

• 3 barns totally destroyed. 4 severely damaged. Grain silo was 3-4 times present height.
• 2 other outbuildings mostly destroyed.
• tree line to the east of point has multiple trees snapped and one uprooted.
• outbuilding was right edge of the track. more tree damage to northwest.

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

An historic tornado outbreak occurred across Illinois on December 1st, with a total of 29 tornadoes touching down across the central part of the state. This made it the largest December tornado outbreak in the state of Illinois since 1957, and the third largest tornado outbreak across Illinois in any month since 1950. Within the National Weather Service Lincoln County Warning Area (CWA), 20 tornadoes touched down...with the most significant being an EF-3 tornado that tore through the city of Taylorville in Christian County. Despite several communities being directly impacted and experiencing major damage, there were no fatalities reported. The severe weather was caused by a deep area of low pressure that tracked from eastern Kansas into north-central Illinois. Warm air surging northward ahead of the low allowed temperatures to soar into the upper 50s and lower 60s, resulting in a narrow corridor of Convective Available Potential Energy (CAPE) values of 500-1000J/kg ahead of an approaching occluded front. Thanks to ample low-level wind shear, numerous supercell thunderstorms developed within the instability axis by mid to late afternoon. Many of the storms produced tornadoes over the next several hours before the storms gradually weakened by mid-evening.

A tornado touched down about 3.2 miles east-southeast of Morrisonville at 5:01 PM CST. It hit a farmstead, destroying 3 barns and severely damaging 4 other out buildings. The tornado was rated EF2 at this location with maximum wind speeds of 112 mph. The tornado continued moving northeastward, hitting several other outbuildings and snapping trees. The tree and outbuilding damage was classified as EF1 damage with wind speeds of 100-110mph. As the tornado continued to the northeast it snapped more large trees and then hit a log home, removing 25-50% of the roof material. It also snapped many other trees on this property and destroyed a couple of small outbuildings, throwing the debris northward into a field. The tornado was rated EF2 at this location with wind speeds of 115mph. The tornado continued northeastward and moved into a wooded area, snapping and uprooting hundreds of trees along its path. It then curved north-northeastward and moved into Hewittville, a small community on the southern edge of Taylorville. Here the tornado destroyed or severely damaged multiple houses. The first house the tornado hit lost most exterior walls and the entire roof, except for the roof over the attached garage, which was on the north side of the house. It also destroyed a second garage on the property and then completely destroyed a mobile home across the street. The tornado was rated EF3 with wind speeds around 150mph at this location. The tornado continued north-northeastward, destroying a barn, pushing an unanchored home off its foundation and completely destroying another mobile home. This mobile home was partially anchored by wood posts set in slots on a concrete foundation over a basement and crawl space. The resident of this home was badly injured and was found unconscious, trapped under debris in the crawl space. The tornado was rated EF3 with wind speeds of 140mph at this location. As the tornado continued, it snapped and uprooted many more trees and took down power lines and power poles. Many more homes were damaged, to a lesser extent than the first few on the south end of town, with some damage to the homes coming from trees or tree branches falling on the homes. As the tornado moved into the northern part of Hewittville, the wind speeds seemed to increase, completely destroying another home and destroying a large, old building that had been part of an old rail-yard. The tornado also damaged other homes and garages in this area. The tornado was rated EF3 with wind speeds of 155mph at this location. As the tornado tracked north-northeastward, it moved into Taylorville, taking down more trees, power lines/poles, and damaging multiple houses. Several homes lost roofs and garages. The tornado continued through Taylorville damaging other homes and several businesses on West Spresser St. and was rated EF2 with wind speeds of 120-125mph at this point. As the tornado crossed Hwy 29 into the northern part of town, it weakened considerably, with the damage becoming less severe and more sporadic. The tornado dissipated 1.8 miles north of Taylorville at 5:25 PM CST. In total, the tornado impacted 506 structures...including major damage to 61 homes and 7 businesses and complete destruction of 28 homes. Total damage was estimated at $118.9 million.

A tornado touched down along IL Route 48 on the southwest edge of Stonington at 5:34 PM CST. At this time, two circulations aloft merged near the west side of Stonington, causing the tornado to take a sharp turn toward the north. Much of the damage in the town was on the northwest side where house roofs were impacted and several garages and sheds were destroyed. The tornado continued tracking to the north and did significant damage to outbuildings at a farm 4 miles north of Stonington. The tornado then curved toward the northeast, damaging several more outbuildings and sheds before it dissipated near Mosquito Creek, about 5.9 miles east-southeast of Mt. Auburn at 5:52 PM CST.

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

24 minutes of warning. NWS ILX issued a tornado warning for this county at 22:37 UTC, 24 minutes before the tornado touched down, in force until 23:15 UTC.

The county was under a tornado watch, issued at 20:17 UTC and running to 01:31 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:58 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.

Taylorville (TAZ), 5 km from the path, in the two hours either side.

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

The Lincoln radar (KILX), 73 km away, was scanning. The volume nearest the touchdown began at 23:02 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 2018 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

39 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.