Tornadoes · United States · Colorado · 2008

EF1 tornado, Westcreek, Colorado, August 23, 2008

This EF1 tornado ran 0.3 miles across Douglas County on August 23, 2008, touching down at 3:02 PM MDT and reaching 75 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 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
August 23, 2008
Touchdown
3:02 PM MDT (21:02 UTC)
Path length
0.3 miles (0.5 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
Property damage
$2,000
County
Douglas County
Touchdown point
39.130, -105.106
Lift-off point
39.130, -105.106
Record number
0808231502-01

What the Weather Service recorded

In Park County at 11-Mile Reservoir, a waterspout caused damage when it transitioned into a landspout. Five vehicles were damaged, including a motor home and a pickup truck with a camper that overturned. One camp trailer was completely destroyed. Several people suffered superficial injuries which consisted of minor cuts and scrapes. In Douglas County near Westcreek, another landspout touched down. One man was seriously injured when he tried to escape several falling trees in his ATV. One of the trees struck his back and broke two vertabrae. Another camper narrowly escaped injury. Seconds after he backed up his truck, a tree came down where his vehicle had been parked.

A landspout tornado developed and caused extensive tree damage. One man was injured when he tried to escape the falling trees in his ATV. One of the trees fell on him and broke two vertebrae in his back.

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

The warnings

6 minutes of warning. NWS PUB issued a tornado warning for this county at 20:56 UTC, 6 minutes before the tornado touched down, in force until 21:31 UTC.

Issued (UTC)ExpiredProductOffice
20:50 UTC21:45 UTCSevere Thunderstorm WarningPUB
20:56 UTC21:31 UTCTornado WarningPUB
21:33 UTC22:15 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 General Thunderstorms Risk. The outlook in force was issued at 19:51 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

9.0 hours before the tornado, 181 km from the path. August 23, 2008.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2008-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 5 joules per kilogram, CIN -484, lifted condensation level 1604 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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, Denver, CO at 12:00Z on 2008-08-23The 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 34 square meters per square second, 0 to 6 km bulk shear 21 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
5 J/kg
Mixed-layer CIN
-484 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1604 m above ground
0-6 km bulk shear
21 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

3.0 hours after it, 181 km from the path. August 24, 2008.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2008-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 53 joules per kilogram, CIN -152, lifted condensation level 2838 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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, Denver, CO at 00:00Z on 2008-08-24The 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 8 square meters per square second, 0 to 6 km bulk shear 15 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
53 J/kg
Mixed-layer CIN
-152 J/kg
Surface CAPE
1241 J/kg
Mixed-layer LCL
2838 m above ground
0-6 km bulk shear
15 kt
0-1 km bulk shear
3 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.5 K/km

Open this sounding in Storm Lab

The surface observations

Air Force Academy (AFF), 31 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:55 UTC7751.62170° 18 kt261025.4
20:55 UTC77.1853180° 19 kt231024.7
21:43 UTC71.653.6220° 12 kt1026.8VCTS
21:47 UTC71.653.6220° 11 kt1026.8VCTS
21:55 UTC71.649.82270° 17 kt221026.8VCTS
22:04 UTC69.850270° 16 kt211027.4TS UP
22:05 UTC69.850270° 16 kt211027.4-TSRA
22:18 UTC64.455.4310° 10 kt1027.8+TSRA
22:20 UTC64.455.4320° 9 kt1027.4+TSRA
22:23 UTC62.655.4350° 11 kt1027.4TSRA
22:31 UTC62.655.4360° 12 kt1027.1-RA
22:55 UTC62.2454.32 4 kt1027.1-DZ

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

The radar

The Denver radar (KFTG), 87 km away, was scanning. The volume nearest the touchdown began at 21:00 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
20:15 UTCTORNADO11-Mile Canyon ReservoiPark, COBRIEF TOUCHDOWN. NO DAMAGE. ALSO HAD A WATERSPOUT OVER THE RESERVIOR.
21:02 UTCTORNADO3 Ese WestcreekDouglas, COEXTENSIVE TREE DAMAGE. ONE MINOR INJURY.
21:05 UTCTSTM WND DMG5 E WestcreekDouglas, COTREE DAMAGE NEAR COUNTY ROAD 348 AND RAMPART ROAD AND HWY 67 AND RAINBOW FALLS ROAD.
21:08 UTCHAIL 17 Nnw Woodland ParkTeller, COHAIL UP TO THE SIZE OF QUARTERS WAS NOTED FROM APPROXIMATELY 308 PM TO 318 PM...HAIL STILL ONGOING.
21:34 UTCTORNADO8 Nnw Woodland ParkTeller, COCOLORADO STATE PATROL REPORTED LARGE TREE OVER THE ROAD AT HIGHWAY 67 AT MILE MARKER 87.5. ALSO REPORTED MANY TREES IN THE AREA SHEARED OFF. OFFICER STATED THAT IT APPEARED A TORNADO WENT THROUGH THE AREA.

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

This ground now

The live radar over the trackEvery 2008 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of August 23, 2008

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 232:15 PM MDTEF1Park, CO1.0100$30,000
August 234:50 PM EDTEF1Cook, GA1.475$25,000
August 233:05 PM MDTEF1Teller, CO0.6100$20,000
August 235:53 PM EDTEF0Putnam, FL3.7100
August 236:12 PM EDTEF0Jefferson, FL0.250

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.