Tornadoes · United States · Colorado · 2021

EF0 tornado, Lake George, Colorado, May 30, 2021

This EF0 tornado ran 0.0 miles across Park County on May 30, 2021, touching down at 2:24 PM MDT and reaching 25 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 30, 2021
Touchdown
2:24 PM MDT (20:24 UTC)
Lifted
2:25 PM MDT (20:25 UTC)
On the ground
1 minutes
Path length
0.0 miles (0.0 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Park County
Touchdown point
38.930, -105.510
Lift-off point
38.930, -105.510
Record number
2105301424-01

What the Weather Service recorded

A short lived tornado touched down in Park County. No damage was observed. The storm also produce penny size hail.

A tornado briefly touched down near Eleven-mile Reservoir. No damage was observed.

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.

Issued (UTC)ExpiredProductOffice
20:06 UTC21:30 UTCFlood AdvisoryBOU

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 19:43 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 (KDNR), 12:00Z

8.4 hours before the tornado, 222 km from the path. May 30, 2021.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2021-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 254 joules per kilogram, CIN -34, lifted condensation level 731 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 2021-05-30The 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 5 square meters per square second, 0 to 6 km bulk shear 31 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
254 J/kg
Mixed-layer CIN
-34 J/kg
Surface CAPE
719 J/kg
Mixed-layer LCL
731 m above ground
0-6 km bulk shear
31 kt
0-1 km bulk shear
2 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
41 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

3.6 hours after it, 222 km from the path. May 31, 2021.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2021-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 8 joules per kilogram, CIN 0, lifted condensation level 558 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 2021-05-31The 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 37 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
8 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
90 J/kg
Mixed-layer LCL
558 m above ground
0-6 km bulk shear
37 kt
0-1 km bulk shear
2 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
70 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

The surface observations

Wilkerson Pass (4BM), 13 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:35 UTC4137.440° 7 kt1029.5-VCTSSN
18:55 UTC4137.440° 5 kt1029.5-SN
19:15 UTC37.435.640° 8 kt151029.5-RA
19:35 UTC37.435.630° 9 kt141029.5-TSRA
19:55 UTC39.237.430° 7 kt151029.1+VCTSSN
20:15 UTC35.635.620° 10 kt181029.5TSRA
20:35 UTC33.832360° 11 kt1029.5TSRA
20:55 UTC33.832190° 8 kt1030.8TSRA
21:15 UTC33.833.850° 5 kt1029.5-TSRA
21:35 UTC33.832100° 5 kt1030.5FG
21:55 UTC323240° 14 kt211030.1+SN
22:15 UTC323230° 13 kt211030.1SN

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

The radar

The Denver radar (KFTG), 126 km away, was scanning. The volume nearest the touchdown began at 20:24 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
20:20 UTCHAIL 0.755 Nw 11-Mile Canyon ResPark, COACCUMULATED UP TO DEPTH OF 1.25 INCHES.
20:25 UTCTORNADO2 Nw 11-Mile Canyon ResPark, COTRAINED SPOTTERS SAW A TORNADO OVER ELEVEN MILE RESERVOIR. NO DAMAGE OR INJURIES AND PATHLENGTH/WIDTH UNKNOWN.

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

This ground now

The live radar over the trackEvery 2021 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of May 30, 2021

17 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 302:23 PM MDTUnratedLas Animas, CO19.9150
May 302:25 PM MDTUnratedLas Animas, CO6.920
May 304:10 PM MDTEF0Union, NM0.450
May 305:34 PM CDTUnratedCimarron, OK0.120
May 305:39 PM CDTUnratedCimarron, OK0.11
May 305:43 PM CDTUnratedCimarron, OK0.11
May 304:44 PM MDTEF0Quay, NM0.550
May 305:56 PM CDTUnratedCimarron, OK0.41
May 306:02 PM CDTUnratedCimarron, OK0.31
May 306:02 PM CDTUnratedCimarron, OK2.950
May 306:13 PM CDTUnratedDallam, TX0.8100
May 306:19 PM CDTUnratedDallam, TX0.350
May 306:21 PM CDTUnratedDallam, TX0.325
May 306:44 PM CDTUnratedCimarron, OK0.530
May 306:46 PM CDTUnratedDallam, TX0.5100
May 307:30 PM CDTUnratedSherman, TX1.2100
May 307:43 PM CDTEF0Sherman, TX4.6150

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.