EF2 tornado, Firestone to Platteville, Colorado, June 7, 2021

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 mph

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mphthis tornado

   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.

Rating

EF2

Date

June 7, 2021

Touchdown

4:59 PM MDT (22:59 UTC)

Lifted

5:34 PM MDT (23:34 UTC)

On the ground

35 minutes

Path length

7.5 miles (12.1 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$531,000

County

Weld County

Touchdown point

40.141, -104.903

Lift-off point

40.251, -104.860

Record number

2106071659-01

12 damage points were recorded along this path by NWS BOU, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 122 mph.

• Windows broken south side of home, most likely due to blowing debris.
• RV trailer flipped on side. 5 inch diameter tree limbs snapped. Power pole snapped. Time retrieved from Police video.
• Anemometer measured 85 mph at 1713 before being blown away. Loss of metal panels on shade structures and main building. Loss of 3 head of cattle.
• Trees uprooted, fence panels and wood road sign blown down

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

A landspout developed in southwest Weld County, 2 miles southwest of Firestone. The tornado traveled north-northeast, and ended 3 miles northwest of Platteville. The tornado reached an intensity of EF-2 on the Enhanced Fujita scale, with estimated wind speeds of 99 mph. There were no injuries, but at least two calves were killed, and several chickens. The cloud base was so high, the landspout was visible from a distance of 40 miles. ||In total, seven properties sustained damage. Two homes were destroyed, meaning more than 50% of the home sustained damaged, with an estimated loss of those homes at $429,176 Three homes were damaged but not destroyed, with the estimated cost of damage at $101,336. Two businesses were hit, a feedlot and a dairy. The feedlot suffered the loss of two buildings, one was caused by a downed power line and the other from the tornado. Downed power lines led to a closure of Weld County Road 21 between Highway 66 and Weld County Road 32.5. The dairy was hit but had limited damage to roofs and some out buildings. The estimated cost of damage to those businesses had not yet been determined.

The tornado touched down in southern Weld County. There were no injuries, but at least two calves were killed, and several chickens. Several homes lost windows and roofing material. One home lost an entire wall and most of its roof, and an unattached garage was completely destroyed with the car inside flipped on its roof. Nearby outbuildings sustained damage, and one caught fire due to downed power lines. Downed power lines also led to a closure of WCR 21 between Highway 66 and WCR 32.5.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

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 Storm Prediction Center had this point in a Marginal Risk. The outlook in force was issued at 19:57 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 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.

Longmont/Vbrand (LMO), 24 km from the path, in the two hours either side.

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

The Denver radar (KFTG), 54 km away, was scanning. The volume nearest the touchdown began at 22:57 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.

Local storm reports within 60 km of the path, in the three hours either side.

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

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

4 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.