Tornadoes · United States · Colorado · 2000

F3 tornado, Dailey, Colorado, July 5, 2000

This F3 tornado ran 6.0 miles across Logan County on July 5, 2000, touching down at 9:10 PM MDT and reaching 1,320 yards wide. It killed nobody and injured 2, and did $750,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

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

  3. F2113 to 157 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. F3158 to 206 mphthis tornado

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F3
Date
July 5, 2000
Touchdown
9:10 PM MDT (03:10 UTC)
Path length
6.0 miles (9.7 km)
Path width
1,320 yards (1207 m)
Deaths
0
Injuries
2
Property damage
$750,000
County
Logan County
Touchdown point
40.680, -102.700
Lift-off point
40.600, -102.720
Record number
437

What the Weather Service recorded

A large and destructive tornado accompanied with hail, up to softball size, ripped through eastern Logan County. An 88-year old farmer and his wife received minor injuries when the tornado flattened their home. The elderly man spared from serious injury when the recliner he was sitting in flipped upside down; just before a wall caved in on top of him. The farmer suffered a cracked vertebra and a lacerated hand. In all, five farmsteads were either damaged or destroyed. Several structures were destroyed, including three homes and numerous outbuildings. One modular home was lifted up and dropped 50 feet away from its foundation. Numerous pieces of farm equipment including, machinery, stock trailers and vehicles were damaged or destroyed. Three square miles of corn crops and several trees were destroyed. Some livestock were also killed. The tornado snapped power poles and downed electrical lines between Holyoke and Fleming. Initial damage estimates to two properties alone were around $750,000.

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

The warnings

42 minutes of warning. NWS BOU issued a tornado warning for this county at 02:28 UTC, 42 minutes before the tornado touched down, in force until 03:30 UTC.

Issued (UTC)ExpiredProductOffice
01:40 UTC02:45 UTCTornado WarningBOU
02:28 UTC03:30 UTCTornado WarningBOU
03:14 UTC04:00 UTCTornado 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. The outlook in force was issued at 00:28 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), 00:00Z

3.2 hours before the tornado, 96 km from the path. July 6, 2000.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2000-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 120 joules per kilogram, CIN -34, lifted condensation level 3637 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 2000-07-06The 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 19 square meters per square second, 0 to 6 km bulk shear 60 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
120 J/kg
Mixed-layer CIN
-34 J/kg
Surface CAPE
278 J/kg
Mixed-layer LCL
3637 m above ground
0-6 km bulk shear
60 kt
0-1 km bulk shear
4 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
9.8 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 12:00Z

8.8 hours after it, 96 km from the path. July 6, 2000.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2000-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 633 joules per kilogram, CIN -260, lifted condensation level 1709 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 2000-07-06The 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 17 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
633 J/kg
Mixed-layer CIN
-260 J/kg
Surface CAPE
1540 J/kg
Mixed-layer LCL
1709 m above ground
0-6 km bulk shear
31 kt
0-1 km bulk shear
5 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
-5 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

The surface observations

Holyoke (HEQ), 38 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
01:53 UTC777180° 16 kt221011.9
02:03 UTC75.271.660° 14 kt1011.2
02:33 UTC75.271.660° 15 kt1011.9
02:53 UTC757240° 13 kt1012.2
03:10 UTC73.471.650° 11 kt1012.5
03:53 UTC747170° 14 kt1013.2
04:31 UTC73.469.840° 11 kt1013.9
04:42 UTC73.469.860° 11 kt1013.9
04:53 UTC727050° 10 kt1013.5

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

The radar

The Goodland radar (KGLD), 166 km away, was scanning. The volume nearest the touchdown began at 03:08 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.

This ground now

The live radar over the trackEvery 2000 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of July 5, 2000

6 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 55:25 PM MDTF0Powder River, MT0.550
July 55:36 PM MDTF0Morrill, NE0.130
July 55:45 PM MDTF0Banner, NE0.340
July 57:04 PM MDTF0Powder River, MT0.550
July 56:15 PM PDTF0Glenn, CA0.20
July 59:18 PM MDTF0Cascade, MT1.010

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.