EF1 tornado, Argos, Indiana, August 15, 2007

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

August 15, 2007

Touchdown

11:15 PM EDT (03:15 UTC)

Lifted

11:21 PM EDT (03:21 UTC)

On the ground

6 minutes

Path length

2.9 miles (4.7 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$500,000

County

Marshall County

Touchdown point

41.245, -86.297

Lift-off point

41.224, -86.250

Record number

0708152115-01

A strong low level jet, remnants of a morning complex of storms from Iowa, and increasing instability all combined to create favorable conditions for damaging winds and isolated supercells. One supercell in particular had a storm motion towards the southeast when the line it was associated with moved mainly eastward. This supercell did produce a tornado in Marshall county.

The initial touchdown of the tornado was located a large grove of trees along Maple Rd. west of Argos and proceeded rapidly southeast to the southeast side of Argos. The tornado skipped along its track, snapping and uprooting numerous trees, downing power poles and lines and damaging some structures. Two businesses on the south side of Argos, near the intersection of US 31 and State Rd 10 suffered moderate damage. The roof of the Topp Industries plant suffered damage. A McDonalds/BP Station suffered metal siding and roofing damage along with the removal of a few gas pumps. A stationary police cruiser was spun by a combination of the strong winds and a sign post striking the car. Neither the officer, nor anyone else in the path of the tornado was injured. The tornado lifted southeast of this point. Exact damage figures were not available, but are estimated to be at least $500,000.

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.

The county was under a tornado watch, issued at 02:35 UTC and running to 04:51 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 00:58 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.

Rochester (RCR), 20 km from the path, in the two hours either side.

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

The Northern Indiana radar (KIWX), 50 km away, was scanning. The volume nearest the touchdown began at 03:16 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 2007 tornado in IndianaEvery tornado in Indiana since 1950Warnings in force in Indiana nowThe forecast where you are

1 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.