Tornadoes · United States · Colorado · 2017

EF0 tornado, Walsh, Colorado, June 25, 2017

This EF0 tornado ran 4.4 miles across Baca County on June 25, 2017, touching down at 3:25 PM MDT and reaching 200 yards wide. It killed nobody, and did $2,000 of property damage.

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 25, 2017
Touchdown
3:25 PM MDT (21:25 UTC)
Lifted
3:45 PM MDT (21:45 UTC)
On the ground
20 minutes
Path length
4.4 miles (7.0 km)
Path width
200 yards (183 m)
Deaths
0
Injuries
0
Property damage
$2,000
County
Baca County
Touchdown point
37.417, -102.321
Lift-off point
37.354, -102.326
Record number
1706251525-01

The damage survey

6 damage points were recorded along this path by NWS PUB, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 105 mph.

  • Wooden power poles were downed and snapped for 3/4 of a mile north of US HWY 160
  • Siding of building bowed out and some roofing gone.
  • A 1/2 mile long pivot irrigation system was damaged/destroyed
  • Metal roof completely separated and debris spread to the southwest.

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

A few severe storms produced very large hail up to the size of baseballs and a tornado near Walsh. Very large hail and severe winds in Walsh caused extensive damage to structures and vehicles. Power was knocked out for several hours and numerous businesses were closed for several days for clean up. Severe microburst winds also occurred west of Walsh. The tornado occurred just west of the microburst damage.

A tornado, at one time multiple-vortex, did some damage to fencing as it moved mainly across open fields around 3 miles west of Walsh and crossed US Highway 160.

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

The warnings

0 minutes of warning. NWS PUB issued a tornado warning for this county at 21:25 UTC, 0 minutes before the tornado touched down, in force until 22:00 UTC.

The county was under a severe thunderstorm watch, issued at 21:05 UTC and running to 03:08 UTC.

Issued (UTC)ExpiredProductOffice
20:35 UTC21:00 UTCSevere Thunderstorm WarningPUB
21:05 UTC22:00 UTCSevere Thunderstorm WarningPUB
21:05 UTC03:08 UTCSevere Thunderstorm WatchPUB
21:25 UTC22:00 UTCTornado WarningPUB
21:43 UTC22:30 UTCTornado WarningPUB
22:13 UTC23:00 UTCSevere Thunderstorm WarningPUB
22:34 UTC23:00 UTCTornado WarningPUB
23:31 UTC00:00 UTCSevere Thunderstorm WarningPUB

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 19:47 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.

Dodge City, (KDDC), 12:00Z

9.4 hours before the tornado, 218 km from the path. June 25, 2017.

Skew-T log-pSkew-T log-p diagram, Dodge City, at 12:00Z on 2017-06-25Temperature 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 -71508, lifted condensation level 1752 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, Dodge City, at 12:00Z on 2017-06-25The 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 26 square meters per square second, 0 to 6 km bulk shear 46 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
0 J/kg
Mixed-layer CIN
-71508 J/kg
Surface CAPE
4 J/kg
Mixed-layer LCL
1752 m above ground
0-6 km bulk shear
46 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
16 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.7 K/km

Open this sounding in Storm Lab

Dodge City, (KDDC), 00:00Z

2.6 hours after it, 218 km from the path. June 26, 2017.

Skew-T log-pSkew-T log-p diagram, Dodge City, at 00:00Z on 2017-06-26Temperature 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 -79381, lifted condensation level 1642 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, Dodge City, at 00:00Z on 2017-06-26The 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 148 square meters per square second, 0 to 6 km bulk shear 55 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
0 J/kg
Mixed-layer CIN
-79381 J/kg
Surface CAPE
296 J/kg
Mixed-layer LCL
1642 m above ground
0-6 km bulk shear
55 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
303 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

The surface observations

Springfield/Comanche Natl Grass (SPD), 28 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:56 UTC7860210° 13 kt201023.7
20:56 UTC7960200° 15 kt201022.7
21:56 UTC7760200° 8 kt1022
22:45 UTC685880° 19 kt241022.7
22:56 UTC7158100° 20 kt1022.7

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

The radar

The Pueblo radar (KPUX), 202 km away, was scanning. The volume nearest the touchdown began at 21:22 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
20:40 UTCHEAVY RAIN 1.519 S HollyProwers, CO1.5 RAINFALL IN ~10 MINUTES. ALSO 0.5 HAIL.
21:25 UTCTORNADO2 Ne WalshBaca, COBRIEF TORNADO REPORTED BY LAW ENFORCEMENT.
21:49 UTCHAIL 1.75WalshBaca, CO
21:53 UTCHAIL 2.75WalshBaca, CO
21:55 UTCHAIL 4.25WalshBaca, CO
22:00 UTCTSTM WND DMG1 W WalshBaca, COTREES DOWN IN THE TOWN OF WALSH.
22:00 UTCHAIL 2.51 W WalshBaca, CO

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

This ground now

The live radar over the trackEvery 2017 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of June 25, 2017

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 256:08 PM CDTEF0Cimarron, OK0.110
June 256:33 PM CDTEF0Cimarron, OK0.110

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.