Tornadoes · United States · Utah · 2005

F0 tornado, Lehi, Utah, May 30, 2005

This F0 tornado ran 0.2 miles across Utah County on May 30, 2005, touching down at 11:30 AM MDT. It killed nobody.

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 mphthis tornado

    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 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
F0
Date
May 30, 2005
Touchdown
11:30 AM MDT (17:30 UTC)
Path length
0.2 miles (0.3 km)
Path width
0 yards (0 m)
Deaths
0
Injuries
0
County
Utah County
Touchdown point
40.380, -111.820
Lift-off point
40.380, -111.820
Record number
334

What the Weather Service recorded

Slow moving thunderstorms dropped copious amounts of rain across parts of northern Utah. 3.5-4" of rain fell in less than 2 hours in Tooele, causing flooding in many residential areas. NUmerous homes and school were flooded as culverts in town broke loose from too much water. Hail accumulated to an incredible 12" deep in some spots! Some specific rainfall totals in Tooele from spotters: 4.00", 3.71" and 3.28...all between 6am and noon.These storms eventually moved southeast and brought more heavy rain and severe weather to Salt Lake and Utah Counties. Large hail was reported in Lehi and Saratoge Springs, and a brief tornado touched down along the northeast shore of Utah Lake.

Brief tornado touchdown along Utah Lake shore...photographed by spotter.

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
12:00 UTC12:30 UTCSevere Thunderstorm WarningSLC
13:04 UTC13:30 UTCSevere Thunderstorm WarningSLC

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 16:18 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.

Salt Lake City I, UT (KSLC), 12:00Z

5.5 hours before the tornado, 45 km from the path. May 30, 2005.

Skew-T log-pSkew-T log-p diagram, Salt Lake City I, UT at 12:00Z on 2005-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 100 joules per kilogram, CIN -70, lifted condensation level 1001 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, Salt Lake City I, UT at 12:00Z on 2005-05-30The 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 -22 square meters per square second, 0 to 6 km bulk shear 29 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
100 J/kg
Mixed-layer CIN
-70 J/kg
Surface CAPE
464 J/kg
Mixed-layer LCL
1001 m above ground
0-6 km bulk shear
29 kt
0-1 km bulk shear
6 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
6 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.5 K/km

Open this sounding in Storm Lab

Salt Lake City I, UT (KSLC), 00:00Z

6.5 hours after it, 45 km from the path. May 31, 2005.

Skew-T log-pSkew-T log-p diagram, Salt Lake City I, UT at 00:00Z on 2005-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 48 joules per kilogram, CIN -23, lifted condensation level 1367 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, Salt Lake City I, UT at 00:00Z on 2005-05-31The 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 64 square meters per square second, 0 to 6 km bulk shear 32 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
48 J/kg
Mixed-layer CIN
-23 J/kg
Surface CAPE
158 J/kg
Mixed-layer LCL
1367 m above ground
0-6 km bulk shear
32 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
81 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.8 K/km

Open this sounding in Storm Lab

The surface observations

Provo Municipal (Awos) (PVU), 20 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
15:35 UTC48.244.6220° 6 kt1013.9
15:55 UTC48.244.6210° 8 kt1013.5
16:15 UTC48.244.6200° 5 kt1013.5
16:35 UTC48.244.6190° 6 kt1013.5
16:55 UTC48.244.6190° 5 kt1013.9
17:15 UTC48.242.8190° 6 kt1014.2
17:35 UTC51.844.6180° 5 kt1014.2
17:55 UTC53.646.4180° 6 kt1014.6
18:15 UTC53.644.6120° 6 kt1014.6
18:35 UTC53.644.6190° 7 kt1014.6
18:55 UTC53.644.6230° 7 kt1014.6
19:15 UTC53.644.6230° 6 kt1014.9

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

The radar

The Salt Lake City radar (KMTX), 111 km away, was scanning. The volume nearest the touchdown began at 17:29 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 2005 tornado in UtahEvery tornado in Utah since 1950Warnings in force in Utah nowThe forecast where you are

The other tornadoes of May 30, 2005

6 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 307:37 AM EDTF1Charleston, SC4.030
May 306:53 PM MDTF0Harding, NM1.0200
May 307:05 PM MDTF0Las Animas, CO0.130
May 308:03 PM MDTF0Baca, CO0.130
May 309:10 PM CDTF0Morton, KS3.275
May 308:25 PM MDTF0Chaves, NM0.150

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.