Tornadoes · United States · Minnesota · 2003

F2 tornado, Lake Crystal to Mankato, Minnesota, July 14, 2003

From Lake Crystal to Mankato, this F2 tornado ran 0.5 miles across Blue Earth County on July 14, 2003, touching down at 8:20 PM CDT and reaching 50 yards wide. It killed nobody, and did $100,000 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 14, 2003
Touchdown
8:20 PM CDT (01:20 UTC)
Path length
0.5 miles (0.8 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$100,000
County
Blue Earth County
Touchdown point
44.120, -94.150
Lift-off point
44.120, -94.150
Record number
1289

What the Weather Service recorded

The second tornado from a cyclic tornadic supercell touched down on the western edge of a farmstead. It snapped a dozen trees and demolished a barn and sheds. The roof of a house was peeled away and four vehicles were moved.

The third tornado in a series touched down in a corn field and trekked straight east. It caused minor house damage and knocked down several sheds and outbuildings, then moved across corn and bean fields before causing minor damage to a farmstead. It dissipated shortly after moving through the farmstead. Videotaped by storm chasers.

The fourth tornado in a series formed atop a bluff on the west side of the Le Sueur River valley, struck two homes down in the river valley, then moved back up the bluffs on the east side of the valley, where it snapped many trees and produced minor damage to some more houses, sheds and outbuildings. Videotaped by storm chasers.

The fifth tornado in a series touched down in a corn field, clipped a couple of storage buildings and a lawn care center, then moved across more fields and a meadow before dissipating.

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

The warnings

7 minutes of warning. NWS MPX issued a tornado warning for this county at 01:13 UTC, 7 minutes before the tornado touched down, in force until 01:45 UTC.

Issued (UTC)ExpiredProductOffice
00:37 UTC01:15 UTCTornado WarningMPX
01:13 UTC01:45 UTCTornado WarningMPX
01:44 UTC02:30 UTCTornado WarningMPX

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, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 01:10 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.

Minneapolis, MN (KMPX), 00:00Z

1.3 hours before the tornado, 92 km from the path. July 15, 2003.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2003-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 438 joules per kilogram, CIN -20, lifted condensation level 837 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 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, Minneapolis, MN at 00:00Z on 2003-07-15The 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 357 square meters per square second, 0 to 6 km bulk shear 60 knots.19395878Sfc1 km3 km6 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
438 J/kg
Mixed-layer CIN
-20 J/kg
Surface CAPE
611 J/kg
Mixed-layer LCL
837 m above ground
0-6 km bulk shear
60 kt
0-1 km bulk shear
31 kt
0-1 km storm-relative helicity
357 m²/s²
0-3 km storm-relative helicity
466 m²/s²
Significant tornado parameter
1.1
Supercell composite
5.1
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 12:00Z

10.7 hours after it, 92 km from the path. July 15, 2003.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2003-07-15Temperature 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 -70752, lifted condensation level 1366 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 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, Minneapolis, MN at 12:00Z on 2003-07-15The 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 97 square meters per square second, 0 to 6 km bulk shear 73 knots.1939587897Sfc1 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
-70752 J/kg
Surface CAPE
4 J/kg
Mixed-layer LCL
1366 m above ground
0-6 km bulk shear
73 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
135 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

The surface observations

Mankato (MKT), 21 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:35 UTC78.871.6160° 9 kt141008.5
23:40 UTC78.871.6160° 9 kt141008.5
23:55 UTC78.871.6160° 11 kt1008.1
00:15 UTC78.871.6170° 9 kt1007.5
00:20 UTC78.871.6170° 9 kt1007.5
00:35 UTC78.871.6170° 8 kt1006.8
00:40 UTC78.871.6170° 8 kt1006.8
00:55 UTC78.871.6190° 6 kt1007.8VCTS
01:15 UTC7771.6190° 8 kt1006.4TS
01:20 UTC7771.6190° 8 kt1006.4
01:35 UTC7773.4240° 14 kt211007.1VCTS
01:40 UTC7773.4240° 14 kt211007.1
01:55 UTC7773.4320° 9 kt1008.5VCTS
02:15 UTC75.269.8310° 9 kt1009.1
02:20 UTC75.269.8310° 9 kt1009.1
02:35 UTC75.271.6320° 9 kt1009.5
02:40 UTC75.271.6320° 9 kt1009.5
02:55 UTC75.271.6320° 8 kt1009.8
03:15 UTC73.471.6310° 7 kt1010.2
03:20 UTC73.471.6310° 7 kt1010.2

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

The radar

The Minneapolis radar (KMPX), 93 km away, was scanning. The volume nearest the touchdown began at 01:18 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 2003 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of July 14, 2003

16 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 149:11 AM EDTF0Somerset, MD1.050
July 143:10 PM CDTF1Pembina, ND5.550
July 143:30 PM CDTF0Pembina, ND to MN3.925
July 144:23 PM CDTF0Cavalier, ND0.525
July 146:05 PM CDTF0Cottonwood, MN0.150
July 147:26 PM CDTF0Saint Louis, MN5.050
July 147:30 PM CDTF0Washington, MN0.125
July 147:30 PM CDTF0Brown, MN2.050
July 147:52 PM CDTF0Brown, MN0.125
July 148:22 PM CDTF1Blue Earth, MN2.550
July 148:27 PM CDTF1Blue Earth, MN3.0220$500,000
July 148:34 PM CDTF1Blue Earth, MN2.0100$100,000
July 148:43 PM CDTF2Blue Earth, MN1.5220$2.0 million
July 148:55 PM CDTF0Waseca, MN0.150
July 149:08 PM CDTF0Emmet, IA0.125
July 149:15 PM CDTF0Hancock, IA0.230

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.