Tornadoes · United States · Nebraska · 2015

EF0 tornado, Firth, Nebraska, May 3, 2015

This EF0 tornado ran 0.3 miles across Lancaster County on May 3, 2015, touching down at 8:33 PM CDT and reaching 100 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
May 3, 2015
Touchdown
8:33 PM CDT (01:33 UTC)
Lifted
8:35 PM CDT (01:35 UTC)
On the ground
2 minutes
Path length
0.3 miles (0.5 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Lancaster County
Touchdown point
40.554, -96.632
Lift-off point
40.552, -96.627
Record number
1505031933-01

What the Weather Service recorded

Thunderstorms developed in two areas of eastern Nebraska on the afternoon of May 3rd. The first and most intense developed near Lincoln at the intersection of a surface trough and a thermal boundary, which was the result of earlier day weaker thunderstorms. Although moisture and thus instability were limited, favorable shear and boundary interaction allowed for a couple of supercells to track southeast across southeast Nebraska producing significant hail and one weak tornado. The other area of thunderstorm development was across northeast Nebraska associated with a cold front. This area had limited instability as well, but also weaker shear than farther south and resulted in less intense storms. The threat of severe weather generally ended shortly after midnight as the storms weakened.

Storm chaser reports, as well as video, indicated a brief tornado occurred from the supercell in southern Lancaster County. No damage was reported from the tornado, and video indicated that the tornado was brief.

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

The warnings

3 minutes of warning. NWS OAX issued a tornado warning for this county at 01:30 UTC, 3 minutes before the tornado touched down, in force until 02:00 UTC.

Issued (UTC)ExpiredProductOffice
22:17 UTC22:45 UTCSevere Thunderstorm WarningOAX
22:44 UTC23:15 UTCSevere Thunderstorm WarningOAX
23:00 UTC23:30 UTCSevere Thunderstorm WarningOAX
23:29 UTC23:48 UTCSevere Thunderstorm WarningOAX
23:55 UTC00:45 UTCSevere Thunderstorm WarningOAX
00:44 UTC01:30 UTCSevere Thunderstorm WarningOAX
01:08 UTC01:45 UTCSevere Thunderstorm WarningOAX
01:30 UTC02:00 UTCTornado WarningOAX
02:02 UTC05:00 UTCFlood AdvisoryOAX
04:53 UTC05:19 UTCSevere Thunderstorm WarningOAX

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 Marginal Risk. The outlook in force was issued at 00:59 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.

Omaha, NE (KOAX), 00:00Z

1.6 hours before the tornado, 88 km from the path. May 4, 2015.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2015-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 552 joules per kilogram, CIN -245, lifted condensation level 2278 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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, Omaha, NE at 00:00Z on 2015-05-04The 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 26 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
552 J/kg
Mixed-layer CIN
-245 J/kg
Surface CAPE
1994 J/kg
Mixed-layer LCL
2278 m above ground
0-6 km bulk shear
26 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
113 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
7.1 K/km

Open this sounding in Storm Lab

Omaha, NE (KOAX), 12:00Z

10.4 hours after it, 88 km from the path. May 4, 2015.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2015-05-04Temperature 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 -105904, lifted condensation level 1167 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 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, Omaha, NE at 12:00Z on 2015-05-04The 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 31 square meters per square second, 0 to 6 km bulk shear 24 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
0 J/kg
Mixed-layer CIN
-105904 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1167 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

The surface observations

Beatrice Municip (BIE), 30 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:35 UTC8558.46180° 17 kt221006.4
23:55 UTC84.258190° 16 kt241006.1
00:15 UTC83.4857.74190° 15 kt221006.1
00:35 UTC83.1257.38190° 17 kt211006.1VCTS
00:55 UTC81.8656.66190° 15 kt191006.4VCTS
01:15 UTC80.7856.66180° 13 kt1006.4
01:35 UTC79.1657.2190° 12 kt171006.8
01:55 UTC7857.3840° 10 kt161008.1
02:15 UTC7858240° 3 kt1009.1
02:35 UTC74.6658.64100° 6 kt151009.8
02:55 UTC72.558.46100° 9 kt151010.2
03:15 UTC70.3458.28100° 8 kt1010.2

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

The radar

The Omaha radar (KOAX), 88 km away, was scanning. The volume nearest the touchdown began at 01:31 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
22:55 UTCHAIL 0.54 Sse LincolnLancaster, NEPEA TO DIME SIZE HAIL AT 27TH AND PINE LAKE RD.
23:10 UTCHAIL 1.75HickmanLancaster, NE
23:16 UTCHAIL 1RocaLancaster, NE
23:35 UTCHAIL 26 E FirthLancaster, NE
23:48 UTCHAIL 23 N AdamsGage, NE
23:50 UTCHAIL 1.754 Sw DouglasOtoe, NE
23:52 UTCHAIL 0.88LincolnLancaster, NEHAIL WAS FALLING NEAR MEMORIAL STADIUM
00:15 UTCHAIL 12 E SterlingJohnson, NE
00:20 UTCHAIL 13 Nw LincolnLancaster, NEDELAYED REPORT. HAIL FELL AT I-180 AND CORNHUSKER.
00:26 UTCHAIL 2SterlingJohnson, NE
00:33 UTCHAIL 1.752 E SterlingJohnson, NE
00:36 UTCHAIL 0.88SterlingJohnson, NELOTS OF TREE LIMBS DOWN FROM LARGER HAIL EARLIER.
00:39 UTCHAIL 1SterlingJohnson, NEHAIL COVERS THE GROUND LIKE SNOW ON EAST EDGE OF TOWN.
01:14 UTCHAIL 1.75LincolnLancaster, NEHAIL AT 33RD AND YANKEE HILL.
01:25 UTCTORNADO1 N AdamsGage, NETORNADO CROSSING HIGWAY 77 NORTH OF CORTLAND.
01:25 UTCTORNADO3 N CortlandLancaster, NETORNADO REPORTED CROSSING HIGWAY 77 NORTH OF CORTLAND. LOCATION ADJUSTED...AND MAY NEED TO BE ADJUSTED MORE AFTER CHECKING WITH LOCAL OFFICIALS AND CHECKING VIDEO. THIS MAY HAVE BEEN A WEAK TORNADO ON A FLANKING LINE OR
01:28 UTCHAIL 1CookJohnson, NESTARTED AS PEA SIZE HAIL AT 821 PM AND GREW TO QUARTER SIZE HAIL AT 828 PM AND CONTINUED HAILING UNTIL 832 PM. PUBLIC REPORT RELAYED BY COOP OBSERVER.
01:35 UTCTORNADO2 Ne AdamsGage, NE
02:00 UTCHAIL 11 E AdamsGage, NE
02:00 UTCHAIL 1JohnsonNemaha, NE
02:05 UTCHAIL 2SterlingJohnson, NE
02:09 UTCHAIL 1.5SterlingJohnson, NE
02:20 UTCHAIL 1.5JohnsonNemaha, NEHAS BEEN HAILING AT LEAST 15 MINUTES
02:40 UTCHAIL 11 S TecumsehJohnson, NE
02:45 UTCHAIL 1.25TecumsehJohnson, NE

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

This ground now

The live radar over the trackEvery 2015 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

The other tornadoes of May 3, 2015

1 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 35:34 PM CDTEF0Dickinson, IA0.350

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.