Tornadoes · United States · Minnesota · 2004

F0 tornado, Clear Lake, Minnesota, May 30, 2004

This F0 tornado ran 0.5 miles across Sherburne County on May 30, 2004, touching down at 3:35 PM CDT and reaching 30 yards wide. 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, 2004
Touchdown
3:35 PM CDT (20:35 UTC)
Path length
0.5 miles (0.8 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
County
Sherburne County
Touchdown point
45.450, -94.000
Lift-off point
45.470, -93.980
Record number
935

What the Weather Service recorded

A weak tornado was reported by trained spotters just north of the intersection of Highway 10 and County Road 6. It dissipated northeast of town a short time later with little if any damage reported.

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. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
20:37 UTC21:00 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 16:38 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), 12:00Z

8.6 hours before the tornado, 74 km from the path. May 30, 2004.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2004-05-30Temperature 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 -58856, lifted condensation level 482 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 2004-05-30The 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 370 square meters per square second, 0 to 6 km bulk shear 55 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
-58856 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
482 m above ground
0-6 km bulk shear
55 kt
0-1 km bulk shear
40 kt
0-1 km storm-relative helicity
370 m²/s²
0-3 km storm-relative helicity
382 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

The surface observations

St. Cloud (STC), 10 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:53 UTC47140° 14 kt19993.2HZ
19:00 UTC140° 14 kt993.2
19:11 UTC-2.2-2.2120° 12 kt19992.9BR
19:26 UTC6.8130° 12 kt18992.9BLSN
19:53 UTC-13120° 6 kt992.9BLSN
20:00 UTC120° 6 kt992.9
20:06 UTC-9.4150° 7 kt993.2UP
20:13 UTC-16.6 5 kt992.9UP
20:26 UTC-5.8170° 10 kt15992.9TS HZ
20:39 UTC-9.4140° 11 kt992.6TS
20:46 UTC-0.4130° 8 kt992.2TS
20:53 UTC4130° 9 kt992.2TS
21:00 UTC3.2130° 9 kt992.2
21:33 UTC21.2180° 12 kt992.6TSUP
21:42 UTC10.4160° 9 kt992.6UP
21:53 UTC-18160° 10 kt992.6TS
22:00 UTC160° 10 kt992.6
22:26 UTC10.4160° 10 kt992.6

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

The radar

The Minneapolis radar (KMPX), 76 km away, was scanning. The volume nearest the touchdown began at 20:35 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 2004 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of May 30, 2004

80 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 301:42 AM CDTF0Wagoner, OK3.5300$10,000
May 301:51 AM CDTF1Mayes, OK7.2600$30,000
May 306:45 AM CDTF1Grundy, TN1.010$30,000
May 309:37 AM CDTF0Tazewell, IL0.110
May 3012:15 PM CDTF0McCracken, KY1.550$20,000
May 301:05 PM ESTF1Owen, IN8.475$300,000
May 301:33 PM ESTF0Fountain, IN0.130
May 302:09 PM ESTF1Monroe, IN7.075$250,000
May 302:18 PM CDTF0Lee, IA0.340$3,000
May 302:22 PM CDTF0Todd, KY0.550
May 302:23 PM CDTF1Lee, IA0.370$20,000
May 302:25 PM ESTF3Crawford, IN15.0400111$5.0 million
May 302:26 PM CDTF0Lee, IA0.340$10,000
May 302:30 PM CDTF1Lee, IA0.570$20,000
May 303:30 PM EDTF1Clark, IN2.010$500,000
May 303:40 PM EDTF0Floyd, IN3.810
May 302:40 PM CDTF2Hopkins, KY7.0175$300,000
May 303:10 PM ESTF1Washington, IN10.630$120,000
May 303:12 PM CDTF0Daviess, KY0.130
May 303:23 PM CDTF0Shannon, MO0.150
May 303:28 PM CDTF0Benton, IA0.240
May 303:36 PM CDTF1Iowa, IA0.250$10,000
May 303:50 PM CDTF0Buchanan, IA0.230
May 303:51 PM CDTF0Buchanan, IA0.340$10,000
May 303:53 PM CDTF1Laclede, MO1.0200$10,000
May 303:56 PM CDTF0Jones, IA0.330
May 304:05 PM CDTF1Madison, IL2.070
May 305:27 PM EDTF0Jefferson, KY0.330$100,000
May 304:50 PM CDTF1Clinton, IL7.080
May 304:55 PM ESTF0Clay, IN0.125
May 305:05 PM CDTF1Woodford, IL9.075
May 305:10 PM CDTF0Fayette, IL0.140
May 305:20 PM CDTF1Saint Louis, MO2.0501$100,000
May 305:45 PM CDTF0Reynolds, MO0.140
May 305:57 PM CDTF0Logan, IL0.1403$250,000
May 306:00 PM ESTF0Morgan, IN0.150$10,000
May 307:05 PM EDTF0Powell, KY0.117
May 306:10 PM ESTF1Morgan, IN5.075$20,000
May 306:11 PM CDTF1Livingston, IL12.050
May 306:12 PM CDTF0Livingston, IL0.220
May 306:24 PM CDTF1Washington, IL4.570
May 306:25 PM CDTF1Washington, IL3.580
May 306:25 PM CDTF1Perry, IL12.075$250,000
May 306:26 PM CDTF1Washington, IL4.0100
May 306:27 PM CDTF1Washington, IL4.570
May 306:28 PM CDTF1Washington, IL18.575$100,000
May 306:30 PM ESTF0Hendricks, IN0.850
May 306:32 PM CDTF0Livingston, IL0.220
May 306:32 PM CDTF0Jackson, IL0.550
May 306:32 PM ESTF0Hendricks, IN4.175
May 306:40 PM CDTF0Livingston, IL1.020
May 307:00 PM CDTF1Nevada, AR10.0100$80,000
May 307:00 PM ESTF2Marion, IN20.010026$19 million
May 307:13 PM CDTF0Clay, IL0.250
May 307:19 PM CDTF0Clay, IL0.250
May 307:26 PM ESTF0Tippecanoe, IN0.120
May 307:28 PM CDTF0Goodhue, MN0.525
May 307:28 PM CDTF0Chisago, MN0.325
May 307:29 PM ESTF2Tippecanoe, IN1.875$1.0 million
May 307:32 PM CDTF0Newton, IN2.520

All 81 of them

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.