Tornadoes · United States · Montana · 2012

EF0 tornado, Judith Basin County, Montana, June 5, 2012

This EF0 tornado ran 3.8 miles across Judith Basin County on June 5, 2012, touching down at 6:41 PM MDT and reaching 400 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 5, 2012
Touchdown
6:41 PM MDT (00:41 UTC)
Lifted
6:54 PM MDT (00:54 UTC)
On the ground
13 minutes
Path length
3.8 miles (6.1 km)
Path width
400 yards (366 m)
Deaths
0
Injuries
0
County
Judith Basin County
Touchdown point
47.101, -109.888
Lift-off point
47.155, -109.870
Record number
1206051841-01

The warnings

30 minutes of warning. NWS TFX issued a tornado warning for this county at 00:11 UTC, 30 minutes before the tornado touched down, in force until 01:00 UTC.

The county was under a tornado watch, issued at 20:37 UTC and running to 04:23 UTC.

Issued (UTC)ExpiredProductOffice
20:37 UTC04:23 UTCTornado WatchTFX
23:13 UTC23:38 UTCSevere Thunderstorm WarningTFX
23:37 UTC00:30 UTCSevere Thunderstorm WarningTFX
23:40 UTC00:15 UTCTornado WarningTFX
00:11 UTC01:00 UTCTornado WarningTFX
00:16 UTC01:15 UTCSevere Thunderstorm WarningTFX

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 19:35 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.

Great_falls, MT (KTFX), 12:00Z

11.3 hours after it, 66 km from the path. June 6, 2012.

Skew-T log-pSkew-T log-p diagram, Great_falls, MT at 12:00Z on 2012-06-06Temperature 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 -77000, lifted condensation level 1157 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Great_falls, MT at 12:00Z on 2012-06-06The 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 -48 square meters per square second, 0 to 6 km bulk shear 82 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
-77000 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1157 m above ground
0-6 km bulk shear
82 kt
0-1 km bulk shear
4 kt
0-1 km storm-relative helicity
-48 m²/s²
0-3 km storm-relative helicity
-18 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

The radar

The Great Falls radar (KTFX), 119 km away, was scanning. The volume nearest the touchdown began at 00:43 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
23:30 UTCHAIL 1.757 Ssw UticaJudith Basin, MTGOLF BALL SIZE HAIL REPORTED BY TRAINED SPOTTER
23:41 UTCTSTM WND DMG3 Wsw HobsonJudith Basin, MTLARGE GARAGE FLATTENED
23:41 UTCTORNADOHobsonJudith Basin, MTTORNADO SPOTTED ON THE GROUND WITH DAMAGE
23:48 UTCTSTM WND GST 90HobsonJudith Basin, MT90 MPH WIND GUST IN HOBSON
23:50 UTCHAIL 12 Nw BenchlandJudith Basin, MTESTIMATED 1.0 INCH HAIL WITH ROTATION IN SE CORNER OF WALL CLOUD
00:00 UTCHAIL 14 Nne WindhamJudith Basin, MT
00:00 UTCHEAVY RAIN 1.154 Nne WindhamJudith Basin, MT
00:18 UTCHAIL 1.75DentonFergus, MTESTIMATED GOLF BALL SIZE HAIL WITH FUNNEL CLOUD OBSERVED
00:53 UTCTORNADOCoffee CreekFergus, MTLOCAL LAW ENFORCEMENT CONFIRMED TORNADO ON GROUND WITH LARGE PATH AND DAMAGE
00:55 UTCHAIL 116 E GeraldineChouteau, MTESTIMATED 1.0 INCH PLUS SIZE HAIL
03:15 UTCHAIL 0.88GeyserJudith Basin, MTNICKEL SIZE HAIL AND 0.50 INCHES OF RAIN

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

This ground now

The live radar over the trackEvery 2012 tornado in MontanaEvery tornado in Montana since 1950Warnings in force in Montana nowThe forecast where you are

The other tornadoes of June 5, 2012

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 53:40 PM MDTEF1Meagher, MT2.8300
June 57:10 PM MDTEF0Chouteau, MT1.1100

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.