F0 tornado, Atwater to Merced Arpt, California, March 28, 2006

1. F040 to 72 mphthis tornado

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

2. F173 to 112 mph

   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

F0

Date

March 28, 2006

Touchdown

2:48 PM PST (22:48 UTC)

Path length

0.2 miles (0.3 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

Property damage

$10,000

County

Merced County

Touchdown point

37.280, -120.470

Lift-off point

37.300, -120.470

Record number

174

A small F0 Tornado occurred just west of Atwater, CA, that resulted in small structure roof damage and the tossing of equipment and trash cans at nearly the same time as another tornado 10 miles to the ESE in Merced County. Locally heavy rain from the thunderstorm activity in Merced County also resulted in reports of roadway flooding just northeast of Livingston by 1633 PST. Urban flooding was the result of locally heavy rain and thundershowers specifically in the Lemoore/Hanford area of Kings County as well as Porterville in Tulare County.

A late report indicated damage from this second small tornado in Merced at 1517 PST shortly after the 1448 PST tornado. There was minimal damage associated with the small track and path. There was an unconfirmed report of another touchdown in the city close to the time this confirmed 1517 PST tornado.

A trained spotter noted a funnel cloud approaching the city of Merced and tracked the northward movement of that funnel. At 1448 PST the funnel removed half of the corrugated roof of a farm maintenance shop and lifted it up and over adjacent power lines to the north. Eyewitness accounts indicated rotation and movement of the lowest level clouds toward the NE approximately 0.19 miles. Other than two ground contact points, beginning and end of the damage track, there was no evidence of any other ground contact from the funnel. Analysis by a local structural engineer aided in the assignment of the F0 rating.

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, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 20:13 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 San Francisco radar (KMUX), 127 km away, was scanning. The volume nearest the touchdown began at 22:48 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 2006 tornado in CaliforniaEvery tornado in California since 1950Warnings in force in California nowThe forecast where you are

2 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.