Tornadoes · United States · California · 2008

EF0 tornado, Alessandro, California, May 22, 2008

This EF0 tornado ran 0.4 miles across Riverside County on May 22, 2008, touching down at 5:40 PM PDT and reaching 10 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  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.

The record

Rating
EF0
Date
May 22, 2008
Touchdown
5:40 PM PDT (00:40 UTC)
Lifted
5:45 PM PDT (00:45 UTC)
On the ground
5 minutes
Path length
0.4 miles (0.6 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Riverside County
Touchdown point
33.803, -117.342
Lift-off point
33.801, -117.348
Record number
0805221840-01

What the Weather Service recorded

A thunderstorm developed near Redlands around 3:30 PM and quickly became severe as it moved south-southwest toward Moreno Valley along the Elsinore Convergence Zone. This storm produced large swaths of hail, flash flooding, and at least four tornadoes.

A trained weather spotter from the Lake Elsinore area captured video of a tornado between 5:40 ��� 5:45 PM. This tornado occurred in an unpopulated area near the Gavilan Hills between Woodcrest and Lake Elsinore, however the exact path is unknown. This was the fourth and final tornado produced by the storm. No reports of damage were received and this tornado was rated EF-0.

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

The warnings

24 minutes of warning. NWS SGX issued a tornado warning for this county at 00:16 UTC, 24 minutes before the tornado touched down, in force until 00:45 UTC.

Issued (UTC)ExpiredProductOffice
19:01 UTC19:49 UTCFlash Flood WarningSGX
19:05 UTC19:45 UTCSevere Thunderstorm WarningSGX
19:55 UTC22:00 UTCFlash Flood WarningSGX
22:46 UTC23:30 UTCSevere Thunderstorm WarningSGX
22:50 UTC00:15 UTCFlash Flood WarningSGX
23:29 UTC00:15 UTCSevere Thunderstorm WarningSGX
23:45 UTC00:00 UTCTornado WarningSGX
23:56 UTC00:30 UTCTornado WarningSGX
00:01 UTC01:30 UTCFlash Flood WarningSGX
00:16 UTC00:45 UTCTornado WarningSGX
00:34 UTC01:00 UTCTornado WarningSGX
01:18 UTC02:45 UTCFlash Flood WarningSGX
18:13 UTC22:15 UTCFlood AdvisorySGX

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 forecast that day

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 19:59 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 air that afternoon

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.

San Diego, CA (KNKX), 00:00Z

0.7 hours before the tornado, 112 km from the path. May 23, 2008.

Skew-T log-pSkew-T log-p diagram, San Diego, CA at 00:00Z on 2008-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -63852, lifted condensation level 4969 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, San Diego, CA at 00:00Z on 2008-05-23The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -33 square meters per square second, 0 to 6 km bulk shear 41 knots.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-63852 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
4969 m above ground
0-6 km bulk shear
41 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.2 K/km

Open this sounding in Storm Lab

San Diego, CA (KNKX), 12:00Z

11.3 hours after it, 112 km from the path. May 23, 2008.

Skew-T log-pSkew-T log-p diagram, San Diego, CA at 12:00Z on 2008-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -74196, lifted condensation level 761 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, San Diego, CA at 12:00Z on 2008-05-23The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -1 square meters per square second, 0 to 6 km bulk shear 38 knots.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-74196 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
761 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
-45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.3 K/km

Open this sounding in Storm Lab

The surface observations

March Afb/Riverside (RIV), 14 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:55 UTC61.746.58180° 13 kt996.6VCSH
23:30 UTC60.846.4360° 7 kt997.3+FC TS
23:38 UTC60.846.430° 8 kt997.6-TSRA
23:44 UTC60.848.2100° 10 kt14997.6+FC TSRAGS
23:50 UTC60.848.2110° 26 kt31997.3+FC TSRAGR
23:55 UTC5949100° 20 kt31997.6+FC -TSRA
00:03 UTC55.450110° 12 kt998-TSRA
00:14 UTC51.846.4160° 15 kt20998-TSRA
00:55 UTC52.1644.78200° 6 kt998.3TS VCSH
01:04 UTC53.646.450° 6 kt998.6-TSRA
01:55 UTC51.848.2 4 kt999.3TSRA
02:23 UTC190° 9 kt1000RA

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

The radar

The Santa Ana Mts radar (KSOX), 27 km away, was scanning. The volume nearest the touchdown began at 00:39 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
22:55 UTCHAIL 0.75CalimesaRiverside, CA3/4 INCH DIAMETER HAIL. HAIL ACCUMULATED 2-3 INCHES IN DEPTH. PUBLIC REPORT.
23:25 UTCFLASH FLOODMoreno ValleyRiverside, CAFLASH FLOODING FORCED THE CLOSURE OF REDLANDS BLVD BETWEEN BAY AVENUE AND ALLESANDRO BLVD. TIME WAS ESTIMATED.
23:30 UTCTORNADO4 Se March AfbRiverside, CAOBSERVERS AT KRIV IN THE MORENO VALLEY AREA REPORTED A TORNADO
23:42 UTCTORNADOMarch AfbRiverside, CAOBSERVERS AT KRIV IN THE MORENO VALLEY AREA REPORTED A TORNADO
23:45 UTCHAIL 0.5Moreno ValleyRiverside, CA
23:50 UTCHAIL 0.88Moreno ValleyRiverside, CANICKEL SIZE HAIL REPORTED JUST EAST OF MARCH FIELD. TIME ESTIMATED.
00:40 UTCFUNNEL CLOUDLake ElsinoreRiverside, CAA FUNNEL CLOUD WAS REPORTED OVER INTERSTATE 15 NEAR LAKE ELSINORE.
01:10 UTCFLASH FLOODOntarioSan Bernardino, CAREPORTS OF FLOODED LANES AT THE INTERSTATE 10 AND 15 TRANSITION.
01:11 UTCFLASH FLOODColtonSan Bernardino, CASEVERE FLASH FLOODING REPORTED IN COLTON WITH WATER UP TO THE HOODS OF VEHICLE.
01:24 UTCFLASH FLOODRiversideRiverside, CAWATER 2 FEET DEEP WAS REPORTED ACROSS ALL LANES OF INTERSTATE 215 JUST SOUTH OF COLUMBIA AVE.
01:40 UTCFLASH FLOOD3 Ne RubidouxRiverside, CAHOME OWNER REPORTS HOUSE FLOODING NEAR CRESTMORE.
01:45 UTCFLASH FLOODRiversideRiverside, CABUILDING FLOODED ON CHICAGO AVENUE NEAR THE 60 AND 215 FREEWAYS.
01:48 UTCFLASH FLOOD2 E ColtonSan Bernardino, CAVEHICLES STUCK IN FLOOD WATERS ON INTERSTATE 10 NEAR WATERMAN AVENUE.
01:53 UTCFLASH FLOOD2 Nw Lake ElsinoreRiverside, CAVEHICLE STUCK IN FLASH FLOOD ON HOSTETTLER ROAD AT TEMESCAL CANYON ROAD.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2008 tornado in CaliforniaEvery tornado in California since 1950Warnings in force in California nowThe forecast where you are

The other tornadoes of May 22, 2008

27 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 2211:26 AM MDTEF3Weld, CO38.71,760178$147 million
May 2212:30 PM MDTEF1Weld, CO0.11001
May 2212:58 PM MDTEF0Albany, WY0.050
May 2212:58 PM MDTEF2Albany, WY25.11001$300,000
May 223:45 PM CDTEF0Gove, KS0.510
May 224:07 PM CDTEF0Gove, KS3.050
May 225:11 PM CDTEF1Sheridan, KS17.6400$500,000
May 225:25 PM CDTEF0Gove, KS10.775$25,000
May 224:29 PM MDTEF0Chase, NE0.150
May 225:32 PM CDTEF0Lane, KS5.4100
May 225:48 PM CDTEF1Decatur, KS12.5300$1.0 million
May 225:55 PM CDTEF2Sheridan, KS9.4300$750,000
May 226:08 PM CDTEF1Gove, KS8.0200$150,000
May 226:18 PM CDTEF0Sheridan, KS2.075
May 226:20 PM CDTEF0Sheridan, KS0.550
May 226:26 PM CDTEF0Trego, KS5.0100
May 224:30 PM PDTEF0Riverside, CA0.920
May 226:31 PM CDTEF1Decatur, KS to NE34.0400$1.9 million
May 226:32 PM CDTEF0Gove, KS0.525
May 224:42 PM PDTEF2Riverside, CA2.8751$350,000
May 224:50 PM PDTEF0Riverside, CA1.020
May 228:00 PM CDTEF1Ness, KS3.5150
May 228:05 PM CDTEF0Lane, KS1.4100
May 228:42 PM CDTEF0Trego, KS6.9150
May 228:57 PM CDTEF1Trego, KS3.0300
May 228:28 PM MDTEF1Laramie, WY0.750$20,000
May 228:32 PM MDTEF0Laramie, WY0.330

What this means

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.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.