Tornado in California, April 21, 2015

Name: Tornado in California, April 21, 2015
Start: 2015-04-21T14:50
End: 2015-04-21T15:05
Location: California

April 21, 2015 · NWS PSR · 1 event in 1 county or zone

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $5,000
Crop damage: None recorded
Events: 1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS PSR wrote it up.

Isolated thunderstorms developed across portions of eastern Riverside county during the afternoon hours on April 21st, and for the most part the storms were not especially strong. However, an isolated storm developed about 6 miles north of Desert Center, and the storm produced a small, rope-like tornado estimated to be EF0 in strength. Numerous photos were taken of this storm by the public, and fortunately the damage that it caused was not substantial. No injuries were reported.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before the first event at Apr 21, 2:00 PM PST, 50 minutes earlier.

Area forecast discussion, Apr 21, 2:00 PM PST, 50 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
300 PM MST TUE APR 21 2015

.SYNOPSIS...A CHANGE IN THE WEATHER PATTERN WILL BEGIN TODAY
STARTING OVER SOUTHEAST CALIFORNIA WITH A SLIGHT CHANCE FOR
THUNDERSTORMS...ALONG WITH SOMEWHAT COOLER TEMPERATURES. THE COOLING
TREND WILL EXPAND INTO ARIZONA WEDNESDAY AND THURSDAY REACHING BELOW
NORMAL VALUES...LITTLE CHANGE FRIDAY. PRECIPITATION CHANCES WILL
EXPAND ACROSS THE DESERT SOUTHWEST THURSDAY AND FRIDAY WITH BEST
CHANCES OVER CENTRAL AND NORTHERN ARIZONA. HIGH PRESSURE BUILDS OVER
THE REGION NEXT WEEK FOR A WARMING TREND.

&&

.DISCUSSION...

REST OF TODAY AND TONIGHT...AS OF EARLY THIS AFTERNOON CONVECTION
OVER OUR FORECAST AREA HAS BEEN LIMITED TO ISOLATED ACTIVITY OVER
JOSHUA TREE NATIONAL PARK WITH ADDITIONAL STORMS IN ADJACENT AREAS
OF THE COACHELLA VALLEY AND FAR SOUTHWEST SAN BERNARDINO COUNTY.
THERE IS STILL TIME YET FOR SOME MORE DESTABILIZATION DUE TO SURFACE
HEATING PLUS THERE MAY BE ANOTHER VORT LOBE TO MOVE THROUGH
ASSOCIATED WITH THE UPPER LOW CENTERED OVER THE SOUTHWEST CALIFORNIA
COAST. THUS WILL HOLD ON TO THE SLIGHT CHANCE OF THUNDERSTORMS OVER
FAR SOUTHEAST CALIFORNIA...INCLUDING LOWER ELEVATIONS...FOR THIS
AFTERNOON AND EVENING. OF NOTE...A MORE SUBSTANTIAL VORT LOBE
APPEARS TO BE ON THE WAY OUT OF OUR FORECAST AREA WHICH MAY LIMIT
SUBSEQUENT DEVELOPMENT.

WEDNESDAY THROUGH FRIDAY...UPSTREAM OF THE SO-CAL UPPER LOW IS AN
ELONGATED TROUGH VARIOUS SHORT WAVES EMBEDDED WITHIN IT. ONE NOTABLE
SHORT WAVE IS HELPING TO DIG THE TROUGH SOUTHWARD. AS THE TROUGH
ADVANCES SLOWLY EASTWARD THE UPPER LOW WILL WEAKEN AND SHIFT
NORTHWARD WEDNESDAY LEADING TO A TEMPORARY DECREASE IN
PRECIP/THUNDERSTORM POTENTIAL. BY THURSDAY...THE TROUGH AXIS WILL BE
OVER THE MOHAVE DESERT AND NORTHERN BAJA MEXICO. THE SYSTEM WILL
HAVE ADVECTED SOME MORE MOISTURE OVER ARIZONA AND SOUTHEAST
CALIFORNIA. SHORT WAVE ENERGY ACTING ON THE MOISTURE WILL LEAD TO A
CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY...MAINLY
OVER OUR EASTERN AREAS INCLUDING METRO PHOENIX. OVER SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...DYNAMICAL FORCING WILL BE WEAKER
BUT COOLER AIR ALOFT WILL AID IN PRECIP POTENTIAL. TIMING AND TRACK
OF SHORT WAVES WILL BE KEY TO PRECIP DEVELOPMENT. THIS ALSO CREATES
UNCERTAINTY DUE TO INHERENT DIFFICULTIES OF BEING ABLE TO PRECISELY
FORECAST THOSE FEATURES. MOISTURE AVAILABILITY DOES NOT LOOK TO BE
OVERWHELMING AND CAPE LOOKS TO BE MODEST AS WELL. THUS POPS ARE
CONSERVATIVE.

SATURDAY THROUGH TUESDAY...THE OVERALL SYNOPTIC PATTERN REMAINS
PROGRESSIVE GOING INTO THE WEEKEND WITH ANOTHER WEAK SHORTWAVE
TROUGH MOVING THROUGH SOMETIME FRIDAY NIGHT OR SATURDAY. FOR
NOW...THIS FEATURE SEEMS TO BE TOO WEAK TO ADD IN ANY POPS FOR
SATURDAY...BUT WE WILL HAVE TO KEEP ANY EYE ON HOW THE MODELS
RESOLVE THIS FEATURE IN COMING MODEL RUNS. TEMPERATURES WILL
GRADUALLY RECOVER THIS WEEKEND WITH HIGHS BACK TO  AROUND NORMAL BY
SUNDAY. EVEN WARMER AIR IS SHOWN BY BOTH THE GFS AND EUROPEAN FOR
EARLY NEXT WEEK AS A RATHER STRONG PACIFIC RIDGE SLIDES OVER THE
WESTERN UNITED STATES. THIS MAY RESULT IN HIGH TEMPERATURES WELL
INTO THE 90S BY THE EARLY TO MIDDLE OF NEXT WEEK.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...

CLEAR/MOSTLY CLEAR SKIES PREVAIL ACROSS THE PHOENIX AREA WHILE THERE
ARE SOME BUILDING CU TO THE WEST OF IMPERIAL AS OF 20Z. NOT
EXPECTING ANY OF THE SHOWERS WEST OF THE COASTAL MOUNTAINS TO MAKE
THEIR WAY INTO IPL OR BLH AND CERTAINLY NO CHANCE OF RAIN IN THE
PHOENIX AREA. SKIES WILL GRADUALLY CLEAR OVERNIGHT. AS FOR
WINDS...EXPECT THE USUAL DIURNAL PATTERNS AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
LINGERING UPPER LEVEL MOISTURE WILL REMAIN IN PLACE EARLY FRIDAY BUT
MORE TYPICAL LATE APRIL WEATHER WILL RETURN OVER THE WEEKEND. MUCH
WARMER TEMPERATURES AND SUBSTANTIALLY DRIER CONDITIONS WILL
PREVAIL...HOWEVER WINDS WILL REMAIN RATHER LIGHT LIMITING FIRE
WEATHER CONCERNS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ/KUHLMAN
AVIATION....LEINS
FIRE WEATHER...LEINS

The radar

The Yuma radar (KYUX), 161 km away, was scanning. The volume nearest the first event began at 22:46 UTC.

Open the radar archive at this moment

Event by event

1 tornado. Local standard time, as filed.

Tornado, Riverside

When: April 21, 2:50 PM PST to 3:05 PM PST
Where: Riverside County, 5.53 mi N of Desert Center
Rating: EF0
Path length: 10 mi
Path width: 200 yd
Property damage: $5,000
Reported by: NWS Storm Survey
Coordinates: 33.800, -115.400

Isolated thunderstorms developed across portions of far southeast California, including eastern Riverside county, during the afternoon hours on April 21st. For the most part the storms were not especially strong, however one thunderstorm located about 6 miles north of Desert Center produced a small, rope-like tornado which traveled nearly 10 miles over mostly open country. The tornado was first reported from an aircraft pilot at about 1447PST and local broadcast media later confirmed the tornado with photographs. Additionally, photos and videos from the public showed the tornado, which did not produce any injuries. The tornado did produce modest damage; several windshields were broken from flying rocks and a number of solar panels were destroyed. The tornado was officially confirmed through an NWS remote storm survey and was classified as an EF0 tornado.

What these are

Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 2015 Every state in 2015 This day in weather history The tornado archive for California, 2015 Warnings in California, April 2015

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 566125.