EF0 tornado, Lake Lou Yaeger to Morrisonville, Illinois, December 1, 2018

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.

Rating

EF0

Date

December 1, 2018

Touchdown

4:47 PM CST (22:47 UTC)

Lifted

4:54 PM CST (22:54 UTC)

On the ground

7 minutes

Path length

3.1 miles (5.0 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$140,000

Counties

Montgomery and Christian counties

Touchdown point

39.348, -89.458

Lift-off point

39.387, -89.428

Record number

1812011647-01

85 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.
• East edge of damage. Storm motion likely paralleled the road.
• 2 other outbuildings mostly destroyed.
• tree line to the east of point has multiple trees snapped and one uprooted.

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

By late morning much of the rain shifted north and east of forecast area allowing partial |clearing to destabilize the atmosphere. Steep lapse rates due to relatively cold mid level temperatures southeast of the upper level low combined with strong low-mid level wind shear due to an 80-kt mid level wind max southeast of the upper level low. This led to the development of isolated low topped supercells along the northward moving warm front and ahead of the eastward moving cold front. Eight tornadoes were surveyed over WFO LSX's forecast area.

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.

The tornado initially touched down just to the west of Interstate 55, along E 1st Road. Power poles were snapped in this location. The tornado continued to the northeast, doing some damage to farm buildings along N 17th Avenue. The tornado continued northeast towards Illinois Route 108 where several trees were snapped. The worst damage was along Illinois Route 48 just west of Raymond, IL where a family residence sustained major roof damage and damage to the garage. The tornado then lifted somewhere near N 23rd Avenue to the northwest of Raymond, IL. Overall, the tornado was rated EF1 with a path length of 8.02 miles and a max path width of 75 yards. No injuries or deaths were reported with this tornado.

The tornado began southeast of Raymond, IL along Illinois Route 127 where several trees were uprooted. The tornado continued northeast, crossing over Blue Grass Creek where it continued to do mainly tree damage. The worst damage was found near Oil Field Road, where a few outbuildings were destroyed. A family residence sustained some minor roof and shingle damage as the tornado crossed Oil Field Road and dissipated. Overall, the tornado was rated EF1 with a path length of 1.97 miles and a max path width of 50 yards. No injuries or deaths were reported with this tornado.

The tornado touched down just south of the Christian/Montgomery County line, near the intersection of E000 North Rd and N400 East Rd. It damaged an outbuilding by knocking out a wall and pushed it off it's foundation, before entering Christian County (WFO ILX County Warning Area). This segment of the tornado (Montgomery County IL) was rated EF0 with a path length of 0.06 miles and a max path width of 25 yards. No injuries or deaths were reported in Montgomery County. The entire tornado was rated EF0. It's path length was 3.1 miles with a max path width of 200 yards. No injuries or deaths were reported.

This tornado touched down in the National Weather Service St. Louis County Warning Area (CWA) just south of the Montgomery/Christian County line near the intersection of East 000 Road and North 400 Road at 4:48 PM CST. It quickly crossed into Christian County, damaging an outbuilding by knocking out a wall and pushing it off it's foundation. It then proceeded to the northeast, doing roof and wall damage to more outbuildings, as well as some tree damage, before dissipating in an open field about 2.9 miles south-southeast of Morrisonville at 4:54 PM CST.

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

15 minutes of warning. NWS LSX issued a tornado warning for this county at 22:32 UTC, 15 minutes before the tornado touched down, in force until 23:00 UTC.

The county was under a tornado watch, issued at 20:18 UTC and running to 01:00 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.

The Lincoln radar (KILX), 88 km away, was scanning. The volume nearest the touchdown began at 22:44 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.