Tornadoes · United States · Colorado · 2018

EF1 tornado, Elizabeth, Colorado, July 27, 2018

This EF1 tornado ran 1.2 miles across Elbert County on July 27, 2018, touching down at 3:51 PM MDT and reaching 50 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 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 27, 2018
Touchdown
3:51 PM MDT (21:51 UTC)
Lifted
3:53 PM MDT (21:53 UTC)
On the ground
2 minutes
Path length
1.2 miles (1.9 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Elbert County
Touchdown point
39.407, -104.580
Lift-off point
39.390, -104.580
Record number
1807271551-01

The damage survey

2 damage points were recorded along this path by NWS BOU, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

Five tornadoes touched down, three of those produced damage on an EF-1 scale. South of Byers, a tornado took to roof off a manufactured home and partially destroyed an outbuilding. The tornado flipped a UPS truck end over end and injured the driver. The second tornado near Ponderosa Park uprooted several trees. The third tornado near Deer Trail tossed a cattle feeder approximately one-quarter of a mile, blew over some farm equipment and blew out the windows of a home. In addition to the tornadoes, severe thunderstorms produced hail up to golf ball size, heavy rain along with some minor |flooding. Multiple power lines were downed and Eads experienced a power outage.

A tornado touched down briefly and uprooted several trees.

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.

The county was under a tornado watch, issued at 19:05 UTC and running to 01:18 UTC.

Issued (UTC)ExpiredProductOffice
04:38 UTC05:30 UTCSevere Thunderstorm WarningBOU
19:05 UTC01:18 UTCTornado WatchBOU
21:08 UTC21:45 UTCSevere Thunderstorm WarningBOU
21:47 UTC22:30 UTCSevere Thunderstorm WarningBOU
22:08 UTC22:49 UTCSevere Thunderstorm WarningBOU

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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:58 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.

Denver, CO (KDEN), 12:00Z

9.9 hours before the tornado, 127 km from the path. July 27, 2018.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2018-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 735 joules per kilogram, CIN -87, lifted condensation level 574 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, Denver, CO at 12:00Z on 2018-07-27The 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 13 square meters per square second, 0 to 6 km bulk shear 27 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
735 J/kg
Mixed-layer CIN
-87 J/kg
Surface CAPE
460 J/kg
Mixed-layer LCL
574 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1
0-3 km lapse rate
4.6 K/km

Open this sounding in Storm Lab

Denver, CO (KDEN), 00:00Z

2.1 hours after it, 127 km from the path. July 28, 2018.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2018-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 683 joules per kilogram, CIN -79, lifted condensation level 1183 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, Denver, CO at 00:00Z on 2018-07-28The 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 -4 square meters per square second, 0 to 6 km bulk shear 28 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
683 J/kg
Mixed-layer CIN
-79 J/kg
Surface CAPE
1906 J/kg
Mixed-layer LCL
1183 m above ground
0-6 km bulk shear
28 kt
0-1 km bulk shear
5 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
6.8 K/km

Open this sounding in Storm Lab

The radar

The Denver radar (KFTG), 43 km away, was scanning. The volume nearest the touchdown began at 21:49 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
21:12 UTCHAIL 1.257 Ne Ponderosa ParkElbert, CO
21:56 UTCTORNADO7 S ByersArapahoe, CO*** 1 INJ *** ROOF TORN OFF HOUSE. FLIPPED UPS TRUCK. 1 INJURY. TIME ESTIMATED.
22:00 UTCTORNADO2 Ne Ponderosa ParkElbert, COTRAINED SPOTTER REPORTED A BRIEF AND WEAK TORNADO.

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

This ground now

The live radar over the trackEvery 2018 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of July 27, 2018

6 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 273:49 PM EDTEF1Chatham, GA2.4100
July 274:03 PM CDTEF0Willacy, TX1.925
July 273:49 PM MDTEF1Arapahoe, CO1.3501$200,000
July 273:55 PM MDTEF1Adams, CO2.050$100,000
July 274:06 PM MDTEF0Adams, CO3.350
July 274:18 PM MDTEF0Arapahoe, CO4.550

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.