Tornadoes · United States · New Mexico · 2009

EF0 tornado, Mills, New Mexico, August 18, 2009

This EF0 tornado ran 0.2 miles across Harding County on August 18, 2009, touching down at 4:09 PM MDT and reaching 20 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 18, 2009
Touchdown
4:09 PM MDT (22:09 UTC)
Lifted
4:11 PM MDT (22:11 UTC)
On the ground
2 minutes
Path length
0.2 miles (0.3 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
County
Harding County
Touchdown point
36.090, -104.200
Lift-off point
36.090, -104.200
Record number
0908181609-01

What the Weather Service recorded

Severe weather erupted across portions of the eastern plains during the afternoon hours as a strong shortwave moved across northern New Mexico. Dewpoints in the mid 50s to low 60s, abundant instability, and 40 to 50 knots of 0 to 6 km shear was present across the northeast quarter of the state. Storms formed along the east slopes of the central mountain chain and quickly became supercellular as they moved into more unstable air. Very large hail, damaging wind gusts and an isolated tornado resulted from the storms.

Multiple reports of a tornado were received approximately 10 miles north of Roy. No damage was reported.

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

The warnings

46 minutes of warning. NWS ABQ issued a tornado warning for this county at 21:23 UTC, 46 minutes before the tornado touched down, in force until 22:15 UTC.

The county was under a severe thunderstorm watch, issued at 18:29 UTC and running to 00:56 UTC.

Issued (UTC)ExpiredProductOffice
18:29 UTC00:56 UTCSevere Thunderstorm WatchABQ
20:27 UTC21:30 UTCSevere Thunderstorm WarningABQ
20:46 UTC21:45 UTCSevere Thunderstorm WarningABQ
21:23 UTC22:15 UTCTornado WarningABQ
21:30 UTC22:30 UTCSevere Thunderstorm WarningABQ
21:45 UTC22:45 UTCSevere Thunderstorm WarningABQ
22:08 UTC23:00 UTCTornado WarningABQ
22:14 UTC23:15 UTCSevere Thunderstorm WarningABQ
22:26 UTC23:30 UTCSevere Thunderstorm WarningABQ
22:29 UTC23:20 UTCSevere Thunderstorm WarningABQ
22:43 UTC23:09 UTCSevere Thunderstorm WarningABQ
22:57 UTC23:29 UTCTornado WarningABQ
23:00 UTC23:18 UTCTornado WarningABQ
23:15 UTC00:15 UTCSevere Thunderstorm WarningABQ

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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:58 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.

Amarillo Airport, TX (KAMA), 12:00Z

10.2 hours before the tornado, 245 km from the path. August 18, 2009.

Skew-T log-pSkew-T log-p diagram, Amarillo Airport, TX at 12:00Z on 2009-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 144 joules per kilogram, CIN -106, lifted condensation level 847 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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, Amarillo Airport, TX at 12:00Z on 2009-08-18The 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 85 square meters per square second, 0 to 6 km bulk shear 32 knots.193958Sfc1 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
144 J/kg
Mixed-layer CIN
-106 J/kg
Surface CAPE
125 J/kg
Mixed-layer LCL
847 m above ground
0-6 km bulk shear
32 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
4.6 K/km

Open this sounding in Storm Lab

Amarillo Airport, TX (KAMA), 00:00Z

1.8 hours after it, 245 km from the path. August 19, 2009.

Skew-T log-pSkew-T log-p diagram, Amarillo Airport, TX at 00:00Z on 2009-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1847 joules per kilogram, CIN -77, lifted condensation level 957 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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, Amarillo Airport, TX at 00:00Z on 2009-08-19The 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 209 square meters per square second, 0 to 6 km bulk shear 31 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
1847 J/kg
Mixed-layer CIN
-77 J/kg
Surface CAPE
3309 J/kg
Mixed-layer LCL
957 m above ground
0-6 km bulk shear
31 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
209 m²/s²
0-3 km storm-relative helicity
285 m²/s²
Significant tornado parameter
1.7
Supercell composite
16.4
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

The radar

The Cannon AFB radar (KFDX), 170 km away, was scanning. The volume nearest the touchdown began at 22:09 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
22:09 UTCTORNADO10 N RoyHarding, NMMULTIPLE TOUCHDOWNS POSSIBLE

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

This ground now

The live radar over the trackEvery 2009 tornado in New MexicoEvery tornado in New Mexico since 1950Warnings in force in New Mexico nowThe forecast where you are

The other tornadoes of August 18, 2009

3 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 181:57 PM CDTEF1Jefferson, TX0.910010$20 million
August 181:16 PM MDTEF1Park, CO9.3100
August 182:18 PM MDTEF0Huerfano, CO1.275

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.