Tornadoes · United States · North Dakota · 2006

F0 tornado, Rolla to Rocklake, North Dakota, June 23, 2006

From Rolla to Rocklake, this F0 tornado ran 6.0 miles across Rolette and Towner counties on June 23, 2006, touching down at 1:52 PM CDT and reaching 25 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mphthis tornado

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

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F0
Date
June 23, 2006
Touchdown
1:52 PM CDT (18:52 UTC)
Path length
6.0 miles (9.7 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
Counties
Rolette and Towner counties
Touchdown point
48.830, -99.600
Lift-off point
48.850, -99.480
Record number
692

What the Weather Service recorded

Tornado tracked by Rolette County Sheriff. No structures impacted and no damage. Tornado crossed from Rolette County (NWS Bismarck) into Towner County (NWS Grand Forks). See Tornado entry for Towner County 1305 to 1310 06/23/06 from National Weather Service Grand Forks, North Dakota.

This tornado originated in Rollette County.

A long and slender tornado briefly touched down in an open field.

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. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
18:54 UTC19:15 UTCTornado WarningBIS
21:21 UTC21:45 UTCTornado WarningBIS

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 16:14 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), 12:00Z

6.9 hours before the tornado, 246 km from the path. June 23, 2006.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 12:00Z on 2006-06-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 97 joules per kilogram, CIN -165, lifted condensation level 1603 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 2006-06-23The 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 74 square meters per square second, 0 to 6 km bulk shear 34 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
97 J/kg
Mixed-layer CIN
-165 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1603 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
74 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
5.1 K/km

Open this sounding in Storm Lab

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

5.1 hours after it, 246 km from the path. June 24, 2006.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 00:00Z on 2006-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 128 joules per kilogram, CIN -9, lifted condensation level 2447 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 2006-06-24The 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 11 square meters per square second, 0 to 6 km bulk shear 44 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
128 J/kg
Mixed-layer CIN
-9 J/kg
Surface CAPE
572 J/kg
Mixed-layer LCL
2447 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
3 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
9.6 K/km

Open this sounding in Storm Lab

The surface observations

Devils_lake (DVL), 93 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
16:55 UTC66.257.2220° 6 kt1020.7
17:15 UTC66.257.2210° 5 kt1020.7
17:35 UTC6857.2230° 4 kt1020.3
17:55 UTC6857.2250° 4 kt1020.3
18:15 UTC69.855.4310° 5 kt1020.3
18:35 UTC69.855.4290° 7 kt1020
18:55 UTC69.857.2310° 7 kt1020
19:15 UTC69.857.2330° 8 kt1019.6
19:35 UTC71.655.4310° 9 kt1019.6
19:55 UTC71.657.2320° 10 kt1019.6
20:15 UTC71.655.4320° 9 kt1019.3
20:35 UTC71.653.6330° 9 kt1019

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

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
18:51 UTCFUNNEL CLOUD8 E RoletteRolette, NDFUNNEL CLOUD ALONG HIGHWAY 66
18:52 UTCTORNADO1 S RollaRolette, NDTORNADO ON GROUND.
18:54 UTCFUNNEL CLOUD1 E RollaRolette, NDFUNNEL CLOUD DISSIPATED THEN REFORMED
19:05 UTCTORNADO 014 Wnw RocklakeTowner, NDTORNADO CONTINUED FROM ROLLETTE COUNTY INTO TOWNER COUNTY. TORNADO WAS INTERMITTENTLY IN CONTACT WITH THE GROUND TO ABOUT 12 WNW ROCKLAKE BY 210 PM.
19:10 UTCTORNADO12 Wnw RocklakeTowner, ND
19:14 UTCTORNADO 04 W RocklakeTowner, NDA LONG AND SLENDER TORNADO TOUCHED DOWN BRIEFLY IN AN OPEN FIELD AND TRAVELLED ABOUT ONE HALF MILE EASTWARD BEFORE LIFTING AROUND 216 PM.
21:18 UTCFUNNEL CLOUD2 W RoletteRolette, NDCOUNTY SHERIFF REPORTS FUNNEL CLOUD 2 MILES WEST OF ROLETTE

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

This ground now

The live radar over the trackEvery 2006 tornado in North DakotaEvery tornado in North Dakota since 1950Warnings in force in North Dakota nowThe forecast where you are

The other tornadoes of June 23, 2006

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 2312:47 PM CDTF0LaMoure, ND3.070
June 231:05 PM CDTF0LaMoure, ND1.040
June 232:14 PM CDTF0Towner, ND0.525
June 237:05 PM MDTF0Sioux, NE0.130

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.