F1 tornado, Harvel to Palmer, Illinois, June 1, 1999

1. F040 to 72 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. F173 to 112 mphthis tornado

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

3. F2113 to 157 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. F3158 to 206 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. F4207 to 260 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. F5261 to 318 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

F1

Date

June 1, 1999

Touchdown

7:11 PM CDT (00:11 UTC)

Path length

12.6 miles (20.3 km)

Path width

0 yards (0 m)

Deaths

0

Injuries

0

Property damage

$750,000

Counties

Montgomery and Christian counties

Touchdown point

39.370, -89.570

Lift-off point

39.500, -89.420

Record number

691

A small tornado formed northwest of Harvel and tracked northeast into Christian County. Damage was limited to trees and crops.

A tornado formed in Montgomery County (WFO St. Louis CWA) and crossed into Christian County 4.4 miles southwest of Morrisonville. Just inside the Christian County line the tornado took the roof off of a shed and smashed it into the southwest corner of a house at the second level bedroom. A camper was tipped over on its side and a visible tornado track could be seen in the cornfield surrounding the house. A mile and a half northeast, a 16 foot wide garage door was completely removed and the west wall of the attached garage was removed as well. A carport on a nearby house was destroyed. Further up the road numerous power poles were blown down, a house was blown 3 inches to the west on its foundation, and another home sustained moderate damage from a fallen tree on one end and the attached garage frame was pushed 6 inches inward on the other end. Two inch diameter tree branches were pierced at least a foot into the ground in this area. About a mile further northeast, the tornado caused around $500,000 in damage to a farmstead. A garage was destroyed and wrapped around some farm equipment. More debris and missiles were projected several inches into the ground and a house was shifted a foot north from its foundation. Several outbuildings, grain bins, and two semis were destroyed. The tornado wrapped a grain bin around a combine and a huge grain wagon. The tornado remained on the ground for another mile and a half knocking over numerous trees and power poles before lifting and dissipating 4 miles north of Palmer. No injuries were reported and damage so far has been estimated around $750,000.

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

16 minutes of warning. NWS LSX issued a tornado warning for this county at 23:55 UTC, 16 minutes before the tornado touched down, in force until 00:30 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. The outlook in force was issued at 16:40 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 live radar over the trackEvery 1999 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

30 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.