Tornadoes · United States · North Dakota · 2011

EF1 tornado, Valley City Arpt to Valley City, North Dakota, July 15, 2011

From Valley City Arpt to Valley City, this EF1 tornado ran 3.0 miles across Barnes County on July 15, 2011, touching down at 3:40 AM CDT and reaching 100 yards wide. It killed nobody, and did $750,000 of property damage.

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 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. EF186 to 110 mphthis tornado

    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
EF1
Date
July 15, 2011
Touchdown
3:40 AM CDT (08:40 UTC)
Lifted
3:46 AM CDT (08:46 UTC)
On the ground
6 minutes
Path length
3.0 miles (4.8 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Property damage
$750,000
Crop damage
$250,000
County
Barnes County
Touchdown point
46.930, -98.030
Lift-off point
46.920, -97.979
Record number
1107150240-01

What the Weather Service recorded

The combination of upper and lower jet support led to some nocturnal thunderstorms across southeast North Dakota and west central Minnesota.

A tornado was briefly viewed wrapped in heavy rains as it approached the northeast corner of Valley City. The tornado became entirely wrapped in heavy rains and downburst winds as it tracked for about three miles across northern portions of Valley City. Numerous large tree limbs and branches were broken down around town. Peak winds were estimated at 95 mph. The downburst winds affected a much wider path.

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

The warnings

15 minutes of warning. NWS FGF issued a tornado warning for this county at 08:25 UTC, 15 minutes before the tornado touched down, in force until 09:15 UTC.

The county was under a severe thunderstorm watch, issued at 08:00 UTC and running to 12:18 UTC.

Issued (UTC)ExpiredProductOffice
07:41 UTC08:45 UTCSevere Thunderstorm WarningFGF
08:00 UTC12:18 UTCSevere Thunderstorm WatchFGF
08:25 UTC09:15 UTCTornado WarningFGF
09:04 UTC10:00 UTCSevere Thunderstorm WarningFGF
10:13 UTC19:29 UTCFlood AdvisoryFGF

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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 05:51 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.

Bismarck Municip, ND (KBIS), 00:00Z

8.7 hours before the tornado, 206 km from the path. July 15, 2011.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 00:00Z on 2011-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2132 joules per kilogram, CIN -66, lifted condensation level 698 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, Bismarck Municip, ND at 00:00Z on 2011-07-15The 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 101 square meters per square second, 0 to 6 km bulk shear 35 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
2132 J/kg
Mixed-layer CIN
-66 J/kg
Surface CAPE
2802 J/kg
Mixed-layer LCL
698 m above ground
0-6 km bulk shear
35 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.2
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

Bismarck Municip, ND (KBIS), 12:00Z

3.3 hours after it, 206 km from the path. July 15, 2011.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 12:00Z on 2011-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 46 joules per kilogram, CIN -521, lifted condensation level 1394 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, Bismarck Municip, ND at 12:00Z on 2011-07-15The 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 -239 square meters per square second, 0 to 6 km bulk shear 40 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
46 J/kg
Mixed-layer CIN
-521 J/kg
Surface CAPE
19 J/kg
Mixed-layer LCL
1394 m above ground
0-6 km bulk shear
40 kt
0-1 km bulk shear
23 kt
0-1 km storm-relative helicity
-239 m²/s²
0-3 km storm-relative helicity
171 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.8
0-3 km lapse rate
3.4 K/km

Open this sounding in Storm Lab

The radar

The Fargo/Grand Forks radar (KMVX), 84 km away, was scanning. The volume nearest the touchdown began at 08:41 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
08:00 UTCHEAVY RAIN 2.75CourtenayStutsman, NDLATE REPORT.
08:15 UTCTSTM WND DMGWimbledonBarnes, NDNUMEROUS TREE BRANCHES 3 TO 4 INCHES IN DIAMETER ON GROUND AROUND TOWN.
08:45 UTCTSTM WND DMGValley CityBarnes, NDNUMEROUS REPORTS OF TREE BRANCHES AND POWERLINES DOWN AROUND TOWN.
09:30 UTCFLOODValley CityBarnes, NDWATER IN THE STREETS IN VALLEY CITY.

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

This ground now

The live radar over the trackEvery 2011 tornado in North DakotaEvery tornado in North Dakota since 1950Warnings in force in North Dakota nowThe forecast where you are

The other tornadoes of July 15, 2011

1 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 155:32 AM CDTEF1Wilkin, MN1.050$5,000

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.