Tornadoes · United States · Nevada · 2009

EF0 tornado, North Fork Stvns Arp to (Awh)Wildhorse Res E, Nevada, June 20, 2009

From North Fork Stvns Arp to (Awh)Wildhorse Res E, this EF0 tornado ran 0.2 miles across Elko County on June 20, 2009, touching down at 2:40 PM PDT and reaching 50 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
June 20, 2009
Touchdown
2:40 PM PDT (21:40 UTC)
Lifted
2:42 PM PDT (21:42 UTC)
On the ground
2 minutes
Path length
0.2 miles (0.3 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Elko County
Touchdown point
41.583, -115.845
Lift-off point
41.583, -115.841
Record number
0906201540-01

What the Weather Service recorded

Two EF0 tornadoes were reported in the vicinity of Wild Horse reservoir. No damage was reported.

A rope-like tornado was observed to touch down for approximately 45 to 90 seconds. The weather spotter was not able to take a picture while the tornado was on the ground, but got a picture after it had lifted about half way up to the cloud base. The Nevada Highway patrol did an aerial survey of the area afterward but found no evidence of damage.

A Highway Patrol Officer observed a tornado approximately 3 miles north of Wild Horse. No damage was observed or reported.

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.

Issued (UTC)ExpiredProductOffice
21:59 UTC22:30 UTCSevere Thunderstorm WarningLKN

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 19:54 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.

Elko, NV (KLKN), 12:00Z

9.7 hours before the tornado, 159 km from the path. June 20, 2009.

Skew-T log-pSkew-T log-p diagram, Elko, NV at 12:00Z on 2009-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1 joules per kilogram, CIN -22, lifted condensation level 567 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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, Elko, NV at 12:00Z on 2009-06-20The 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 19 square meters per square second, 0 to 6 km bulk shear 72 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
1 J/kg
Mixed-layer CIN
-22 J/kg
Surface CAPE
16 J/kg
Mixed-layer LCL
567 m above ground
0-6 km bulk shear
72 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

Elko, NV (KLKN), 00:00Z

2.3 hours after it, 159 km from the path. June 21, 2009.

Skew-T log-pSkew-T log-p diagram, Elko, NV at 00:00Z on 2009-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 38 joules per kilogram, CIN -52, lifted condensation level 1313 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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, Elko, NV at 00:00Z on 2009-06-21The 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 -35 square meters per square second, 0 to 6 km bulk shear 18 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
38 J/kg
Mixed-layer CIN
-52 J/kg
Surface CAPE
105 J/kg
Mixed-layer LCL
1313 m above ground
0-6 km bulk shear
18 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
-35 m²/s²
0-3 km storm-relative helicity
-40 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.0
0-3 km lapse rate
6.6 K/km

Open this sounding in Storm Lab

The surface observations

Elko (EKO), 85 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:56 UTC6146140° 4 kt1008.8
20:56 UTC6145140° 11 kt1007.8
21:56 UTC6243120° 8 kt1007.8
22:56 UTC5345 4 kt171008.8+RA
23:07 UTC51.844.650° 4 kt1008.8-RA

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

The radar

The Elko radar (KLRX), 123 km away, was scanning. The volume nearest the touchdown began at 21:42 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
21:40 UTCTORNADO5 S WildhorseElko, NVTRAINED SPOTTER REPORTED A TORNADO BRIEFLY TOUCHING DOWN FOR 45 TO 90 SECONDS ABOUT 5 MILES SOUTH OF WILDHORSE RESERVOIR. TORNADO CATEGORY WAS AN EF0.
22:00 UTCTORNADO3 N WildhorseElko, NVNEVADA HIGHWAY PATROL REPORTED A BRIEF TORNADO TOUCHDOWN JUST NORTH OF WILDHORSE RESERVOIR. TORNADO CATEGORY WAS AN EF0.

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 NevadaEvery tornado in Nevada since 1950Warnings in force in Nevada nowThe forecast where you are

The other tornadoes of June 20, 2009

14 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 203:31 PM EDTEF0Harford, MD1.0100
June 203:44 PM EDTEF1Baltimore, MD5.0150
June 203:00 PM PDTEF0Elko, NV0.350
June 205:44 PM CDTEF0Kiowa, KS1.050
June 206:10 PM CDTEF0Coffey, KS1.425
June 206:17 PM CDTEF1Pawnee, KS5.0100$50,000
June 207:11 PM CDTEF0Franklin, KS0.325
June 207:22 PM CDTEF0Lane, KS4.250
June 207:44 PM CDTEF0Barton, KS1.2502$75,000
June 207:55 PM CDTEF1McPherson, KS0.975$75,000
June 208:05 PM CDTEF0McPherson, KS4.5100$200,000
June 208:45 PM CDTEF0Marion, KS0.975$100,000
June 209:10 PM CDTEF0Lincoln, KS1.255
June 209:12 PM CDTEF0Lincoln, KS0.450

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.