Tornadoes · United States · Idaho · 2012

EF0 tornado, Declo to Albion, Idaho, September 1, 2012

From Declo to Albion, this EF0 tornado ran 1.0 miles across Cassia County on September 1, 2012, touching down at 4:20 PM MDT and reaching 20 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
September 1, 2012
Touchdown
4:20 PM MDT (22:20 UTC)
Lifted
4:30 PM MDT (22:30 UTC)
On the ground
10 minutes
Path length
1.0 miles (1.6 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
County
Cassia County
Touchdown point
42.520, -113.561
Lift-off point
42.520, -113.541
Record number
1209011620-01

What the Weather Service recorded

On the afternoon os September 1st two torandoes touched down in Cassia County between 4 and 5 pm MDT. One was just east of Declo and the second was 5 miles east northeast of Albion.

A tornado was spotted with confirmation with photos east of Declo. The tornado occurred in open land and caused no damage and was not long lasting.

A weak tonado was confirmed with photographs about 4 to 5 miles east northeast of Albion. It was in open land and did no damage.

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

The warnings

10 minutes of warning. NWS PIH issued a tornado warning for this county at 22:10 UTC, 10 minutes before the tornado touched down, in force until 23:00 UTC.

Issued (UTC)ExpiredProductOffice
19:18 UTC04:00 UTCRed Flag WarningPIH
21:19 UTC22:00 UTCSevere Thunderstorm WarningPIH
21:28 UTC22:15 UTCTornado WarningPIH
22:10 UTC23:00 UTCTornado WarningPIH
22:56 UTC23:41 UTCSevere Thunderstorm WarningPIH
00:33 UTC02:36 UTCFlood AdvisoryPIH

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 19:56 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

10.3 hours before the tornado, 191 km from the path. September 1, 2012.

Skew-T log-pSkew-T log-p diagram, Elko, NV at 12:00Z on 2012-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 122 joules per kilogram, CIN -213, lifted condensation level 1415 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, Elko, NV at 12:00Z on 2012-09-01The 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 73 square meters per square second, 0 to 6 km bulk shear 43 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
122 J/kg
Mixed-layer CIN
-213 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1415 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.8 K/km

Open this sounding in Storm Lab

Elko, NV (KLKN), 00:00Z

1.7 hours after it, 191 km from the path. September 2, 2012.

Skew-T log-pSkew-T log-p diagram, Elko, NV at 00:00Z on 2012-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 72 joules per kilogram, CIN -42, lifted condensation level 2853 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, Elko, NV at 00:00Z on 2012-09-02The 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 3 square meters per square second, 0 to 6 km bulk shear 25 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
72 J/kg
Mixed-layer CIN
-42 J/kg
Surface CAPE
476 J/kg
Mixed-layer LCL
2853 m above ground
0-6 km bulk shear
25 kt
0-1 km bulk shear
4 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
9.8 K/km

Open this sounding in Storm Lab

The surface observations

Burley Municipal (BYI), 18 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:53 UTC77500° 0 kt1015.2
21:53 UTC7552340° 6 kt1014.6
22:06 UTC73.451.8310° 8 kt1014.9TS
22:15 UTC60.851.8240° 34 kt421016.6+TSRA
22:22 UTC5951.8270° 17 kt421015.2+TSRA
22:25 UTC60.851.8290° 20 kt341015.2+TSRA
22:34 UTC60.853.6300° 12 kt261014.9-TSRA
22:41 UTC62.653.6300° 10 kt221015.2-TSRA
22:53 UTC63510° 0 kt1015.2TS
23:10 UTC60.851.8180° 7 kt1016.6-RA
23:27 UTC60.853.6210° 11 kt1018.3VCTS -RA
23:42 UTC60.853.6190° 10 kt1018.6-RA
23:53 UTC6152160° 12 kt1017.6-RA

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

The radar

The Pocatello radar (KSFX), 96 km away, was scanning. The volume nearest the touchdown began at 22:19 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
22:20 UTCTORNADODecloCassia, IDKMVT CHANNEL 11 FORWARDED A PICTURE OF A TORNADO IN THE AREA EAST OF DECLO. TIME IS ESTIMATED FROM RADAR.
22:40 UTCTORNADO5 Ene AlbionCassia, IDKMVT CHANNEL 11 FORWARDED A PICTURE OF A TORNADO NEAR ALBION. ABLE TO CONFIRM TIME AND LOCATION AFTER GATHER INFORMATION FROM VIEWER.
23:50 UTCTSTM WND DMG8 W American FallsPower, IDIDAHO POWER LOST THREE 60+ FOOT TOWERS NEAR RAST ROAD IN AMERICAN FALLS DUE TO THUNDERSTORM WIND GUSTS.

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 IdahoEvery tornado in Idaho since 1950Warnings in force in Idaho nowThe forecast where you are

The other tornadoes of September 1, 2012

14 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
September 111:48 AM CDTEF0Woodford, IL0.120
September 112:03 PM CDTEF0Woodford, IL0.720
September 112:05 PM CDTEF0Woodford, IL2.375$1,000
September 112:32 PM CDTEF0Marshall, IL0.120
September 11:08 PM CDTEF0Stark, IL1.350
September 11:11 PM CDTEF0Stark, IL1.120
September 11:24 PM CDTEF0Stark, IL0.950
September 14:19 PM CDTEF2Clay, AR0.975$5.0 million
September 14:22 PM CDTEF0Clay, AR0.125
September 14:32 PM CDTEF0Butler, MO3.020
September 14:43 PM CDTEF0Butler, MO4.320
September 14:40 PM MDTEF0Cassia, ID1.020
September 16:41 PM EDTEF0Marion, IN0.125
September 16:03 PM CDTEF0Dunklin, MO0.025$100,000

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.