EF2 tornado, Griffith to Ross, Indiana, August 4, 2008

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 mphthis tornado

   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

EF2

Date

August 4, 2008

Touchdown

8:27 PM CDT (01:27 UTC)

Lifted

8:31 PM CDT (01:31 UTC)

On the ground

4 minutes

Path length

2.7 miles (4.4 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

Property damage

$1.0 million

County

Lake County

Touchdown point

41.552, -87.432

Lift-off point

41.549, -87.379

Record number

0808041927-01

A line of powerful thunderstorms moved across northwest Indiana during the evening hours of August 4th. These storms produced widespread and significant wind damage.

A tornado touched down just northeast of the Ridge Road and Cline Avenue intersection. Damage occurred at the Griffith Park Plaza Mall where windows were blown out of a row of stores and a portion of a roof was blown off of a vacant store. The damage path continued to the east, behind the mall. Two parked semi-trailers in the back of the mall were shifted eastward while a third was completely knocked over. The area to the east of this mall in the subdivision along and north of 37th Avenue near Lafayette Avenue and Rensselaer Avenue sustained some of the strongest wind damage from this tornado. Two houses on Lafayette Avenue had their roofs blown off with another house on Rensselaer Avenue also having its roof collapsed and a garage door pushed inward. Other significant damage that occurred was at the Habitat for Humanity storage building at Colfax and Ridge Road. Here, a cinder block storage building completely toppled to the ground. Although the building was knocked over, it appears as though the main cause of it faltering was due to a large tree that fell on top of it. At a nearby gas station within feet of this building, no damage occurred and people actually witnessed the tornado descend on the shelter.

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

10 minutes of warning. NWS LOT issued a tornado warning for this county at 01:17 UTC, 10 minutes before the tornado touched down, in force until 01:45 UTC.

The county was under a severe thunderstorm watch, issued at 00:21 UTC and running to 07:00 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 Moderate Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:14 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 Chicago radar (KLOT), 57 km away, was scanning. The volume nearest the touchdown began at 01:28 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 2008 tornado in IndianaEvery tornado in Indiana since 1950Warnings in force in Indiana nowThe forecast where you are

7 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.