Tornadoes · United States · Arizona · 2023

EF0 tornado, Moenave, Arizona, August 8, 2023

This EF0 tornado ran 5.0 miles across Coconino County on August 8, 2023, touching down at 12:50 PM MST 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
August 8, 2023
Touchdown
12:50 PM MST (19:50 UTC)
Lifted
1:00 PM MST (20:00 UTC)
On the ground
10 minutes
Path length
5.0 miles (8.0 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Coconino County
Touchdown point
36.020, -111.390
Lift-off point
36.091, -111.408
Record number
2308081350-01

What the Weather Service recorded

The air flow over Arizona slowly transitioned from a west to east trajectory, to more southerly. This was due to a nearly stationary low forming off the western coast of California, which will provided some dynamical forcing. This allowed moisture to move northward from Mexico. Scattered to numerous showers and thunderstorms formed over the north-central Arizona.

Landspout tornado was spotted 10 miles north of Cameron, Arizona at 1:50 MDT. Only visible lofted debris was dust. Dissipated within 10 minutes after sighting. Video on Twitter.

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

The warnings

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 forecast that day

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 16:30 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.

Flgstf/Belemont, AZ (KFGZ), 12:00Z

7.8 hours before the tornado, 99 km from the path. August 8, 2023.

Skew-T log-pSkew-T log-p diagram, Flgstf/Belemont, AZ at 12:00Z on 2023-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 261 joules per kilogram, CIN -83, lifted condensation level 1293 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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, Flgstf/Belemont, AZ at 12:00Z on 2023-08-08The 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 206 square meters per square second, 0 to 6 km bulk shear 44 knots.1939587897Sfc1 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
261 J/kg
Mixed-layer CIN
-83 J/kg
Surface CAPE
27 J/kg
Mixed-layer LCL
1293 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
32 kt
0-1 km storm-relative helicity
206 m²/s²
0-3 km storm-relative helicity
258 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

Flgstf/Belemont, AZ (KFGZ), 00:00Z

4.2 hours after it, 99 km from the path. August 9, 2023.

Skew-T log-pSkew-T log-p diagram, Flgstf/Belemont, AZ at 00:00Z on 2023-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 239 joules per kilogram, CIN -28, lifted condensation level 2000 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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, Flgstf/Belemont, AZ at 00:00Z on 2023-08-09The 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 116 square meters per square second, 0 to 6 km bulk shear 27 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
239 J/kg
Mixed-layer CIN
-28 J/kg
Surface CAPE
1631 J/kg
Mixed-layer LCL
2000 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
116 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9
0-3 km lapse rate
9.2 K/km

Open this sounding in Storm Lab

The surface observations

Grand Canyon Park (GCN), 69 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
17:50 UTC250° 14 kt1025.7
17:54 UTC8149240° 14 kt301025.7
17:55 UTC240° 16 kt221025.7
18:00 UTC240° 13 kt1025.7
18:05 UTC240° 19 kt271025.7
18:10 UTC 1025.4
18:15 UTC 241025.4
18:20 UTC250° 16 kt241025.4
18:25 UTC240° 18 kt221025.1
18:30 UTC250° 21 kt271025.4
18:35 UTC240° 20 kt1025.4
18:40 UTC 1025.4
18:45 UTC 231025.1
18:50 UTC250° 17 kt1025.1
18:54 UTC8446250° 17 kt281025.1
19:00 UTC 231025.1
19:10 UTC 281025.1
19:15 UTC 1025.1
19:20 UTC240° 16 kt1025.1
19:25 UTC260° 13 kt1025.1
19:30 UTC 1025.1
19:35 UTC 261024.7
19:40 UTC250° 18 kt1025.1
19:45 UTC260° 13 kt181025.1
19:50 UTC 1024.7
19:54 UTC8447250° 16 kt331025.1
19:55 UTC 221025.1
20:00 UTC 301024.7
20:05 UTC 1025.1
20:10 UTC260° 11 kt1024.7
20:15 UTC 1024.7
20:20 UTC 301024.7
20:25 UTC240° 14 kt211024.7
20:30 UTC 301024.7
20:35 UTC 261024.7
20:40 UTC 241024.7
20:45 UTC 221024.7
20:50 UTC230° 18 kt221024.7
20:54 UTC8343240° 14 kt241024.7
20:55 UTC240° 14 kt1024.4
21:00 UTC 261024.4
21:05 UTC260° 15 kt221024
21:10 UTC250° 15 kt211024.4
21:15 UTC240° 16 kt211024.4
21:20 UTC240° 17 kt221024.4
21:25 UTC 241024.4
21:30 UTC250° 15 kt1024
21:35 UTC240° 18 kt241024
21:40 UTC240° 15 kt221023.7
21:45 UTC240° 18 kt221024

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

The radar

The Flagstaff radar (KFSX), 166 km away, was scanning. The volume nearest the touchdown began at 19:50 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 2023 tornado in ArizonaEvery tornado in Arizona since 1950Warnings in force in Arizona nowThe forecast where you are

The other tornadoes of August 8, 2023

13 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 811:20 AM EDTEF1Plymouth, MA0.9300$10,000
August 811:52 AM EDTEF0Barnstable, MA1.2650$2,000
August 84:29 PM MDTUnratedWashington, CO0.050
August 84:39 PM MDTEF3Washington, CO15.7212$1.0 million
August 84:50 PM MDTUnratedMorrill, NE0.125
August 85:29 PM MDTEF0Washington, CO0.050
August 85:30 PM MDTUnratedYuma, CO5.3200
August 86:04 PM MDTEF0Yuma, CO1.7193
August 86:19 PM MDTUnratedYuma, CO1.0150
August 86:23 PM MDTUnratedYuma, CO0.975
August 87:00 PM MDTUnratedYuma, CO0.5150
August 87:25 PM MDTEF2Kit Carson, CO5.3150$30,000
August 89:17 PM MDTUnratedSherman, KS1.375

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.