Tornadoes · United States · Wyoming · 2009

EF0 tornado, La Grange to Harrisburg, Wyoming, June 7, 2009

From La Grange to Harrisburg, this EF0 tornado ran 5.5 miles across Banner and Goshen counties on June 7, 2009, touching down at 2:03 PM CDT 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
June 7, 2009
Touchdown
2:03 PM CDT (19:03 UTC)
Lifted
2:13 PM CDT (19:13 UTC)
On the ground
10 minutes
Path length
5.5 miles (8.8 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
Counties
Banner and Goshen counties
Touchdown point
41.589, -104.115
Lift-off point
41.589, -104.115
Record number
0906071303-01

What the Weather Service recorded

A line of thunderstorms produced hail over eastern laramie county and a landspout type tornado over extreme southeast Goshen county into far northwest Banner county of the Nebraska panhandle.

A line of thunderstorms produced hail over eastern Laramie County and a landspout type tornado over extreme southeast Goshen county into far northwest Banner county of the Nebraska panhandle.

Narrow landspout type tornado tracked over open rangeland.

Brief tornado touchdown 15 miles west northwest of Harrisburg that caused no damage.

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

The warnings

12 minutes of warning. NWS CYS issued a tornado warning for this county at 18:51 UTC, 12 minutes before the tornado touched down, in force until 19:08 UTC.

Issued (UTC)ExpiredProductOffice
18:51 UTC19:08 UTCTornado WarningCYS

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, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 16:31 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.

Denver, CO (KDNR), 12:00Z

7.1 hours before the tornado, 205 km from the path. June 7, 2009.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2009-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -73437, lifted condensation level 2464 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Denver, CO at 12:00Z on 2009-06-07The 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 -4 square meters per square second, 0 to 6 km bulk shear 59 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
0 J/kg
Mixed-layer CIN
-73437 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2464 m above ground
0-6 km bulk shear
59 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

4.9 hours after it, 205 km from the path. June 8, 2009.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2009-06-08Temperature 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 -208, lifted condensation level 1916 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, Denver, CO at 00:00Z on 2009-06-08The 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 -45 square meters per square second, 0 to 6 km bulk shear 43 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
1 J/kg
Mixed-layer CIN
-208 J/kg
Surface CAPE
187 J/kg
Mixed-layer LCL
1916 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
-45 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1
0-3 km lapse rate
7.3 K/km

Open this sounding in Storm Lab

The surface observations

Torrington Municipal Airport (TOR), 53 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
17:28 UTC57.248.2100° 8 kt1008.8
17:53 UTC5849110° 7 kt1008.8
18:53 UTC57500° 0 kt1008.8
19:53 UTC5751140° 11 kt1007.5
20:53 UTC5746120° 8 kt1007.1

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

The radar

The Cheyenne radar (KCYS), 75 km away, was scanning. The volume nearest the touchdown began at 19:02 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
18:50 UTCFUNNEL CLOUD1 Ne AlbinLaramie, WY
18:50 UTCTORNADO15 Wnw HarrisburgBanner, NE
18:50 UTCTORNADO20 Wsw ScottsbluffScotts Bluff, NE
19:02 UTCFUNNEL CLOUD10 Sw Pine BluffsLaramie, WYLARAMIE COUNTY DEPUTY - FUNNEL CLOUDS 2 MILES SOUTH OF MILE MARKER 390 ON INTERSTATE 80.
19:03 UTCTORNADO4 Se La GrangeGoshen, WYSMALL NARROW TORNADO.
19:05 UTCFUNNEL CLOUD11 Sw AlbinLaramie, WYFUNNEL CLOUD REPORTED BY USAF PERSONNEL NORTH OF EGBERT MOVING EAST.
19:10 UTCTORNADO15 Wnw HarrisburgBanner, NE
19:15 UTCHAIL 1.59 Se BurnsLaramie, WYQUARTER TO PING PONG SIZED HAIL.

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 WyomingEvery tornado in Wyoming since 1950Warnings in force in Wyoming nowThe forecast where you are

The other tornadoes of June 7, 2009

10 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 71:05 PM MDTEF0Adams, CO0.650$25,000
June 71:50 PM MDTEF1Arapahoe, CO5.51002$500,000
June 72:23 PM MDTEF0Arapahoe, CO0.150$10,000
June 72:27 PM MDTEF1Elbert, CO0.250$75,000
June 72:43 PM MDTEF0Elbert, CO0.1150
June 75:17 PM CDTEF0Cass, IA0.225
June 76:33 PM CDTEF0Dallas, IA1.9125$10,000
June 78:13 PM CDTEF0DeKalb, MO0.125
June 78:27 PM CDTEF0DeKalb, MO0.125
June 710:44 PM CDTEF0Caldwell, MO0.125

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.