Tornadoes · United States · Colorado · 2007

EF0 tornado, Lamar, Colorado, May 14, 2007

This EF0 tornado ran 0.5 miles across Prowers County on May 14, 2007, touching down at 9:50 PM MDT and reaching 75 yards wide. It killed nobody.

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 mphthis tornado

    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 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
EF0
Date
May 14, 2007
Touchdown
9:50 PM MDT (03:50 UTC)
Lifted
9:52 PM MDT (03:52 UTC)
On the ground
2 minutes
Path length
0.5 miles (0.8 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
County
Prowers County
Touchdown point
38.008, -102.620
Lift-off point
38.008, -102.620
Record number
0705142150-01

What the Weather Service recorded

Severe thunderstorms occurred from the I-25 corridor to the far southeastern plains. The most severe storms occurred in northern Prowers County...where large hail...damaging wind...and tornados were reported.

A brief tornado was spotted. There was no known damage.

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

The warnings

39 minutes of warning. NWS PUB issued a tornado warning for this county at 03:11 UTC, 39 minutes before the tornado touched down, in force until 04:15 UTC.

The county was under a severe thunderstorm watch, issued at 21:00 UTC and running to 04:00 UTC.

Issued (UTC)ExpiredProductOffice
21:00 UTC04:00 UTCSevere Thunderstorm WatchPUB
02:47 UTC03:45 UTCSevere Thunderstorm WarningPUB
03:11 UTC04:15 UTCTornado WarningPUB
04:14 UTC04:57 UTCTornado 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 Slight Risk. The outlook in force was issued at 00:56 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

3.8 hours before the tornado, 214 km from the path. May 15, 2007.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2007-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 774 joules per kilogram, CIN -8, lifted condensation level 1671 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 2007-05-15The 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 -26 square meters per square second, 0 to 6 km bulk shear 52 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
774 J/kg
Mixed-layer CIN
-8 J/kg
Surface CAPE
1394 J/kg
Mixed-layer LCL
1671 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
4 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.0
0-3 km lapse rate
8.5 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 12:00Z

8.2 hours after it, 214 km from the path. May 15, 2007.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2007-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -20331, lifted condensation level 568 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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 12:00Z on 2007-05-15The 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 44 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
0 J/kg
Mixed-layer CIN
-20331 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
568 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
16 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

The surface observations

Lamar (LAA), 9 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
01:53 UTC735420° 10 kt1013.5
02:53 UTC725420° 13 kt1014.2
03:14 UTC69.853.6190° 18 kt261015.9
03:16 UTC66.251.8230° 25 kt371015.6
03:22 UTC64.450230° 25 kt551016.3
03:46 UTC55.453.6220° 15 kt381019+RA BR
03:53 UTC6053360° 12 kt311019+RA
04:01 UTC5953.670° 10 kt191020RA
04:06 UTC57.253.660° 7 kt141020RA BR
04:15 UTC60.853.640° 9 kt1020RA
04:37 UTC60.855.480° 11 kt1019.6-RA
04:53 UTC615570° 11 kt141019.3-RA

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

The radar

The Pueblo radar (KPUX), 145 km away, was scanning. The volume nearest the touchdown began at 03:49 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
03:19 UTCTSTM WND GST 63LamarProwers, CO
03:25 UTCHIGH SUST WINDS 631 S LamarProwers, COSTRONG THUNDERSTORM WINDS KNOCKED DOWN 2 RUSSIAN OLIVE TREES...APPROXIMATELY 30 FEET TALL AND 9 INCHES IN DIAMETER.
03:37 UTCTORNADOBristolProwers, COSPOTTER IN SHERIDAN LAKE OBSERVED TORNADO AND DEBRIS CLOUD ESTIMATED TO BE NEAR OR A LITTLE NORTH OF BRISTOL.
03:50 UTCTORNADO5 S LamarProwers, COTORNADO SPOTTED BY AMBULANCE 5 MILES SOUTH OF LAMAR. REPORT RELAYED BY LOCAL OFFICIALS.
04:05 UTCHAIL 1.75BristolProwers, COGOLF BALL SIZE HAIL REPORT IN BRISTOL RELAYED TO NWS BY LOCAL MEDIA.
04:10 UTCTORNADOBristolProwers, COSPOTTER FROM SHERIDAN LAKE ESTIMATES TORNADO NEAR OR A LITTLE NORTH OF BRISTOL.
04:25 UTCTORNADOBristolProwers, COSPOTTER IN SHERIDAN LAKE REPORTS A SIZEABLE TORNADO ESTIMATED TO BE IN THE BRISTOL AREA.

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

This ground now

The live radar over the trackEvery 2007 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of May 14, 2007

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 146:25 PM CDTEF0Norton, KS0.310
May 146:28 PM MDTEF0Weld, CO0.150
May 149:37 PM MDTEF0Prowers, CO0.875
May 1410:10 PM MDTEF0Prowers, CO0.575

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.