Tornadoes · United States · Colorado · 1996

F2 tornado, Strasburg, Colorado, July 13, 1996

This F2 tornado ran 12.0 miles across Adams County on July 13, 1996, touching down at 10:45 PM MDT and reaching 440 yards wide. It killed nobody, and did $220,000 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 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. F3158 to 206 mph

    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
F2
Date
July 13, 1996
Touchdown
10:45 PM MDT (04:45 UTC)
Path length
12.0 miles (19.3 km)
Path width
440 yards (402 m)
Deaths
0
Injuries
0
Property damage
$220,000
County
Adams County
Touchdown point
39.800, -104.400
Lift-off point
39.650, -104.220
Record number
542

What the Weather Service recorded

A fast moving tornado ripped a 12-mile path of destruction near Strasburg, in eastern Adams County. The tornado caused extensive structural damage to several galvanized metal grain silos, farm buildings and sheds in the area. The roof of a two-story log home was completely torn off. The home received substantial damage from the wind and heavy rain that followed the tornado. Several other homes in the area sustained roof damage and a number of power poles were downed along Highway 36.

The second tornado was much weaker and on the ground for a much shorter time. The twister did manage to topple a church steeple and down a number of power and light poles. In addition, several large trees were also damaged and a camper shell was picked up and knocked into a nearby tree.

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

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

4.8 hours before the tornado, 94 km from the path. July 14, 1996.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 1996-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1605 joules per kilogram, CIN -40, lifted condensation level 1342 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 1996-07-14The 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 79 square meters per square second, 0 to 6 km bulk shear 39 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
1605 J/kg
Mixed-layer CIN
-40 J/kg
Surface CAPE
1199 J/kg
Mixed-layer LCL
1342 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
298 m²/s²
Significant tornado parameter
0.9
Supercell composite
7.1
0-3 km lapse rate
8.0 K/km

Open this sounding in Storm Lab

The surface observations

Denver Intnl Airport (DEN), 32 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:00 UTC

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

The radar

The Denver radar (KFTG), 21 km away, was scanning. The volume nearest the touchdown began at 04:46 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 1996 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of July 13, 1996

6 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 132:05 AM EDTF1Charles, MD0.335$150,000
July 132:45 AM EDTF0Dorchester, MD0.550$40,000
July 133:35 AM EDTF1Calvert, MD1.250$120,000
July 133:40 PM MDTF0Weld, CO0.150
July 136:40 PM MDTF2Logan, CO0.5100
July 1310:55 PM MDTF1Adams, CO2.0100

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.