F1 tornado, Bedford, Iowa, April 5, 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

April 5, 1999

Touchdown

4:02 PM CDT (21:02 UTC)

Path length

3.0 miles (4.8 km)

Path width

0 yards (0 m)

Deaths

0

Injuries

0

Property damage

$100,000

County

Taylor County

Touchdown point

40.620, -94.780

Lift-off point

40.630, -94.730

Record number

809

An intense low pressure system moved out of the Rockies and intensified over Kansas before lifting northeast into western Iowa during the evening of the 5th. The system was very similar to the tornado outbreak of 27 May 1995 with the exception that this system did not have as much deep moisture to work with. A tropospheric fold was noted in the upper air analysis on the morning of the 5th over Oklahoma. This helped intensify the system during the day. As the upper low lifted northeast, it took on a negative tilt. A strong mid level jet streak formed with wind speeds of 100 knots observed at 500 mb on the Lathrop, MO wind profiler. Earlier in the day a round of non severe convection moved across Iowa. Late in the afternoon a line of thunderstorms fired up over southeast Nebraska into northwest Missouri. The storms raced north at speeds of up to 80 knots at times. This event was a low topped convection event. The first tornado reports came during the early afternoon hours over southeast Nebraska. By mid afternoon the line pushed into southwest Iowa. Several small spin up tornadoes were reported. The strongest tornado occurred in Taylor County. It touched down briefly twice southwest of Bedford along Highway 148. This tornado had an intermittent track for about 3 miles. Once the tornado weakened, the storms produced high winds farther to the northeast. Four miles north of Bedford, damage was reported on a farmstead there. The storms continued to move north and brought high winds to Prescott, in Adams County. A bit later, another cell spawned a brief tornado touchdown south of Lenox, also in Taylor County. Damage estimates from Taylor County showed in excess of $10,000 damage occurred on 6 farmsteads. Most of the damage was done to outbuildings, however a few barns were damaged as well. About an hour later the same line of storms was moving through Warren County. Gusty winds were reported with it as well as a brief tornado touchdown west of New Virginia. Some minor wind damage occurred west of Indianola, in Warren County, before the storms weakened with the loss of daytime heating.

very intermittent track

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. One was issued for the county at another hour that day.

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 19:57 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.

Clarinda (ICL), 25 km from the path, in the two hours either side.

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

The Des Moines radar (KDMX), 150 km away, was scanning. The volume nearest the touchdown began at 21:03 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.

The live radar over the trackEvery 1999 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

25 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.