EF0 tornado, Perris, California, September 9, 2012

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

September 9, 2012

Touchdown

2:00 PM PDT (21:00 UTC)

Lifted

3:00 PM PDT (22:00 UTC)

On the ground

60 minutes

Path length

0.0 miles (0.0 km)

Path width

10 yards (9 m)

Deaths

0

Injuries

0

County

Riverside County

Touchdown point

33.780, -117.230

Lift-off point

33.780, -117.230

Record number

1209091500-01

Monsoonal moisture in easterly flow aloft brought showers and thunderstorms to the mountains and deserts each afternoon and evening. The activity on the 9th was mainly in the upper deserts, San Bernardino Mountains and the Inland Empire near Lake Elsinore. Flooding was reported along Highway 74 in Lake Elsinore with 3 to 5 inches of water covering the roadway, along with several downed trees, and a land spout in the nearby city of Perris. Outflow boundaries from storms created strong winds which picked up dust and lowered visibility in the Coachella Valley and near Borrego Springs. Visibility was also lowered to near zero at times with wind gusts around 60 MPH reported in the areas. Storms were more widespread on the 10th as a trough of low pressure drifted north from Mexico. Thunderstorms occurred over most mountain and desert locations, as well as the Inland Empire. Flash flooding was reported in Forest Falls and along Highway 76 in northern San Diego County. Highway 76 was closed for about an hour in the afternoon due to 12 to 18 inches of mud and debris in the road.

A land spout was observed at 1330 PST along interstate 215 and highway 74 in Perris. No funnel was observed at the cloud base, and the land spout remained nearly stationary. Pictures and a video were submitted by spotters.

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.

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 General Thunderstorms Risk. The outlook in force was issued at 19:54 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 Santa Ana Mts radar (KSOX), 38 km away, was scanning. The volume nearest the touchdown began at 21:00 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 2012 tornado in CaliforniaEvery tornado in California since 1950Warnings in force in California nowThe forecast where you are

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.