Tornadoes · United States · Arizona · 2015

EF0 tornado, Sibyl, Arizona, September 22, 2015

This EF0 tornado ran 0.6 miles across Cochise County on September 22, 2015, touching down at 3:40 PM MST and reaching 25 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
September 22, 2015
Touchdown
3:40 PM MST (22:40 UTC)
Lifted
3:42 PM MST (22:42 UTC)
On the ground
2 minutes
Path length
0.6 miles (1.0 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Cochise County
Touchdown point
31.944, -110.184
Lift-off point
31.950, -110.175
Record number
1509221640-01

What the Weather Service recorded

Tropical depression 16 E formed about 90 miles west of Cabo San Lazaro, Mexico during the afternoon of September 20, then moved northeast becoming a remnant low centered just southwest of Nogales by September 21. Abundant tropical moisture contributed to heavy rain and flash flooding on the 21st. As mid level flow increased on the 22nd, severe thunderstorms developed and one tornado occurred.

A brief tornado touched down north of St. David.

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

What forecasters said that day

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

NWS Tucson, AZ wrote its last area forecast discussion before the tornado touched down at Sep 22, 3:32 PM MST, 8 minutes earlier.

Area forecast discussion, Sep 22, 3:32 PM MST, 8 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
332 PM MST TUE SEP 22 2015

.SYNOPSIS...EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
FOR THE REST OF TODAY...FOLLOWED BY A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS NEAR THE MOUNTAINS EAST OF TUCSON WEDNESDAY. DRY
CONDITIONS WITH ABOVE NORMAL DAYTIME TEMPERATURES WILL THEN PREVAIL
THURSDAY INTO EARLY NEXT WEEK.

&&

.DISCUSSION...AN INTERESTING DAY SO FAR ACROSS SOUTHEASTERN ARIZONA
WITH LOW TOPED SHOWERS AND THUNDERSTORMS PRODUCING SOME RELATIVELY
HIGH PRECIPITATION AMOUNTS OUT OF OTHERWISE UNIMPRESSIVE STORMS.
LINGERING TROPICAL MOISTURE ALONG WITH SOME DECENT SHEAR RANGING
FROM 30 TO 40 KTS EVEN HELPED TO POP OUT A COUPLE VERY WELL
STRUCTURED STORMS...OR LOW TOPPED MINI SUPERCELLS...ONE THAT HAS SO
FAR TREKKED FROM CENTRAL PIMA INTO GRAHAM COUNTY. DRYING ALOFT AND
AT THE MID LEVELS HAS HELPED SUPPRESS THE OVERALL SEVERE THREAT SO
FAR TODAY. HOWEVER LOOKING AT THE SOUNDINGS 1.4 INCHES CRAMMED
MOSTLY BELOW 600 MB IS MAKING FOR VERY EFFICIENT RAINERS KEEPING
FLOODING THE MAJOR CONCERN FOR THE REMAINDER OF TODAY...ESPECIALLY
FOR AREAS THAT HAVE ALREADY SEEN ABUNDANT RAINFALL. SOME STRONGER
GUSTS ARE STILL POSSIBLE WITH THE MORE WELL STRUCTURED STORMS. THIS
AFTERNOON AND TONIGHT REMNANTS OF A WEAK LOW WILL MAKE IT'S WAY
ACROSS THE SOUTHERN ARIZONA...POSSIBLY ADDING SOME ADDITIONAL UPPER
LEVEL FORCING TO THE MIX. THIS COULD HELP KEEP THE SHOWER AND
THUNDERSTORMS ACTIVITY AROUND INTO TONIGHT.

FOLLOWING TONIGHT A SIGNIFICANT DRYING TREND IS IN STORE AS HIGH
PRESSURE BUILDS IN OVER THE AREA. SOME MOUNTAIN RAIN MAY STILL BE
POSSIBLE IN FAR EASTERN AREAS TOMORROW...OTHERWISE DRY CONDITIONS
WILL PREVAIL FOR THE REST OF THE WEEK. AS THE RIDGE BUILDS INTO THE
AREA THE ACCOMPANYING WARMING TREND WILL QUICKLY BRING HIGH
TEMPERATURES TO NEAR NORMAL TOMORROW...CONTINUING ON TO BE ABOVE
AVERAGE FROM THURSDAY INTO NEXT WEEK. TUCSON WILL HAVE POSSIBILITY
OF DRIFTING BACK INTO THE TRIPLE DIGITS...THOUGH AS OF NOW THE
FORECAST IS STAYING JUST SHY OF THE CENTURY MARK. STARTING THURSDAY
LOW LEVEL FLOW WILL BEGIN TO SHIFT TO THE EAST. BECOMING GUSTY BY
FRIDAY THROUGH THE START OF NEXT WEEK. THE EAST WINDS MAY CONTRIBUTE
TO THE WARMING TREND...WITH DOWNSLOPE WARMING POTENTIALLY ADDING A
FEW DEGREES ONTO THE CURRENT FORECAST.

&&

.AVIATION...VALID THRU 24/00Z.
SCATTERED TO NUMEROUS -TSRA/-SHRA WILL OCCUR THRU 23/03Z...THEN
ISOLATED TO SCATTERED -TSRA/-SHRA TIL 23/07Z. SCT-BKN CLOUD DECKS AT
4-7K FT AGL WITH OCCASIONAL MVFR CONDITIONS THRU 23/05Z...THEN
DECREASING CLOUDS FROM WEST TO EAST...WITH SCT CLOUDS AT 8-12K FT
AGL BY 23/14Z. SURFACE WIND GENERALLY LESS THAN 10 KTS THRU THE
FORECAST PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL
CONTINUE THROUGH THIS EVENING...FOLLOWED BY A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS EAST OF TUCSON WEDNESDAY. DRY CONDITIONS
WILL THEN PREVAIL THURSDAY THROUGH MONDAY. EXPECT LOCALLY GUSTY EAST
WINDS FRIDAY INTO SATURDAY. OTHERWISE...NORMAL DIURNAL WIND TRENDS
WILL BE THE RULE WITH ABOVE NORMAL DAYTIME TEMPERATURES RETURNING
THURSDAY AND CONTINUING INTO EARLY NEXT WEEK.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

In the hours before

Special weather statement, Sep 22, 10:19 AM MST, 5 hours 21 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
1019 AM MST TUE SEP 22 2015

AZZ504>506-221800-
SOUTH CENTRAL PINAL COUNTY INCLUDING ELOY/PICACHO PEAK STATE PARK AZ-
TUCSON METRO AREA INCLUDING TUCSON/GREEN VALLEY/MARANA/VAIL AZ-
SOUTHEAST PINAL COUNTY INCLUDING KEARNY/MAMMOTH/ORACLE AZ-
1019 AM MST TUE SEP 22 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL PINAL AND
NORTHEASTERN PIMA COUNTIES UNTIL 1100 AM MST...

AT 1018 AM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
NEAR RED ROCK...MOVING NORTHEAST AT 25 MPH.

WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM. IN
ADDITION TO STRONG WINDS...HEAVY RAINFALL IS OCCURRING WITH THIS
STORM...PRIMARILY NEAR THE PIMA AND PINAL COUNTY BORDERS NEAR THE
I-10 CORRIDOR.

LOCATIONS IMPACTED INCLUDE...
ORO VALLEY...MARANA...TORTOLITA...AVRA VALLEY...RED ROCK...DOVE
MOUNTAIN AND PICTURE ROCKS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 3237 11143 3259 11143 3275 11108 3258 11100
      3239 11098
TIME...MOT...LOC 1718Z 246DEG 21KT 3252 11132

CARLAW
Special weather statement, Sep 22, 10:59 AM MST, 4 hours 41 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
1059 AM MST TUE SEP 22 2015

AZZ504>506-221845-
SOUTH CENTRAL PINAL COUNTY INCLUDING ELOY/PICACHO PEAK STATE PARK AZ-
TUCSON METRO AREA INCLUDING TUCSON/GREEN VALLEY/MARANA/VAIL AZ-
SOUTHEAST PINAL COUNTY INCLUDING KEARNY/MAMMOTH/ORACLE AZ-
1059 AM MST TUE SEP 22 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN PINAL AND NORTHERN
PIMA COUNTIES UNTIL 1145 AM MST...

AT 1059 AM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
NEAR DOVE MOUNTAIN...MOVING EAST AT 25 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM ALONG WITH TORRENTIAL RAINFALL WITH RATES LOCALLY
EXCEEDING ONE INCH PER HOUR POSSIBLE.

LOCATIONS IMPACTED INCLUDE...
ORO VALLEY...MARANA...ORACLE...SADDLEBROOKE...CATALINA...ORACLE
JUNCTION...BIOSPHERE 2 AND DOVE MOUNTAIN.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 3243 11115 3250 11122 3259 11129 3280 11092
      3265 11082 3250 11083
TIME...MOT...LOC 1759Z 255DEG 20KT 3255 11110

CARLAW
Special weather statement, Sep 22, 12:00 PM MST, 3 hours 40 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
1200 PM MST TUE SEP 22 2015

AZZ506-511-514-221945-
GALIURO AND PINALENO MOUNTAINS INCLUDING MOUNT GRAHAM AZ-
SOUTHEAST PINAL COUNTY INCLUDING KEARNY/MAMMOTH/ORACLE AZ-
SANTA CATALINA AND RINCON MOUNTAINS INCLUDING MOUNT
LEMMON/SUMMERHAVEN AZ-
1200 PM MST TUE SEP 22 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN PINAL COUNTY UNTIL
1245 PM MST...

AT 1159 AM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
ABOUT 10 MILES WEST OF SAN MANUEL...MOVING EAST AT 35 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM. IN ADDITION...THIS STORM HAS PRODUCED ANYWHERE BETWEEN
ONE HALF AND THREE QUARTERS OF AN INCH OF RAINFALL IN 30 MINUTES.
THIS MAY LEAD TO PONDING OF WATER ON ROADWAYS.

LOCATIONS IMPACTED INCLUDE...
MAMMOTH...SAN MANUEL...ORACLE AND CAMPO BONITO.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 3252 11074 3259 11075 3266 11081 3290 11053
      3274 11045 3254 11045
TIME...MOT...LOC 1859Z 247DEG 31KT 3262 11068

CARLAW
Special weather statement, Sep 22, 12:33 PM MST, 3 hours 7 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
1233 PM MST TUE SEP 22 2015

AZZ506-507-509-511-222015-
UPPER GILA RIVER AND ARAVAIPA VALLEYS INCLUDING CLIFTON/SAFFORD AZ-
UPPER SAN PEDRO RIVER VALLEY INCLUDING SIERRA VISTA/BENSON AZ-
GALIURO AND PINALENO MOUNTAINS INCLUDING MOUNT GRAHAM AZ-
SOUTHEAST PINAL COUNTY INCLUDING KEARNY/MAMMOTH/ORACLE AZ-
1233 PM MST TUE SEP 22 2015

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN PINAL AND SOUTHWESTERN
GRAHAM COUNTIES UNTIL 115 PM MST...

AT 1231 PM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 10
MILES EAST OF SAN MANUEL...MOVING EAST AT 30 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM. IN ADDITION...TORRENTIAL RAINFALL IS OCCURRING WITH
AUTOMATED GAUGES IN SAN MANUEL RECORDING NEARLY ONE INCH OF RAIN IN
30 MINUTES. THIS HEAVY RAINFALL MAY CAUSE PONDING OF WATER ON LOW-
WATER CROSSINGS.

LOCATIONS IMPACTED INCLUDE...
KLONDYKE.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 3256 11054 3264 11056 3269 11062 3297 11021
      3277 11002 3254 11002
TIME...MOT...LOC 1931Z 254DEG 28KT 3266 11046

CARLAW
Local storm report, Sep 22, 2:51 PM MST, 49 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

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.

Tuscon, AZ (KDMA), 12:00Z

10.7 hours before the tornado, 72 km from the path. September 22, 2015.

Skew-T log-pSkew-T log-p diagram, Tuscon, AZ at 12:00Z on 2015-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 134 joules per kilogram, CIN -19, lifted condensation level 969 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Tuscon, AZ at 12:00Z on 2015-09-22The 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 90 square meters per square second, 0 to 6 km bulk shear 37 knots.19395878Sfc1 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
134 J/kg
Mixed-layer CIN
-19 J/kg
Surface CAPE
796 J/kg
Mixed-layer LCL
969 m above ground
0-6 km bulk shear
37 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

The surface observations

Fort Huachuca/Libby (FHU), 43 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:00 UTC

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

The radar

The Tucson radar (KEMX), 43 km away, was scanning. The volume nearest the touchdown began at 22:38 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.

This ground now

The live radar over the trackEvery 2015 tornado in ArizonaEvery tornado in Arizona since 1950Warnings in force in Arizona nowThe forecast where you are

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.