Tornadoes · United States · Minnesota · 2005

F0 tornado, Brooklyn Park, Minnesota, September 21, 2005

This F0 tornado ran 0.1 miles across Hennepin County on September 21, 2005, touching down at 7:08 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
September 21, 2005
Touchdown
7:08 PM CDT (00:08 UTC)
Path length
0.1 miles (0.2 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
County
Hennepin County
Touchdown point
45.120, -93.330
Lift-off point
45.120, -93.330
Record number
1171

What the Weather Service recorded

A damage survey determined there was a brief tornado just north of widespread and significant wind damage in Brooklyn Park. The tornado touched down just west of the intersection of Oxbow Creek Drive and Kyle Avenue.

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

The warnings

0 minutes of warning. NWS MPX issued a tornado warning for this county at 00:08 UTC, 0 minutes before the tornado touched down, in force until 01:00 UTC.

Issued (UTC)ExpiredProductOffice
23:38 UTC00:45 UTCSevere Thunderstorm WarningMPX
00:08 UTC01:00 UTCTornado WarningMPX
00:48 UTC03:45 UTCFlash Flood WarningMPX
00:57 UTC01:26 UTCSevere Thunderstorm WarningMPX
01:38 UTC02:00 UTCSevere Thunderstorm WarningMPX
02:21 UTC03:00 UTCSevere Thunderstorm 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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 20:00 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

0.1 hours before the tornado, 37 km from the path. September 22, 2005.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2005-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2043 joules per kilogram, CIN -38, lifted condensation level 1714 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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 00:00Z on 2005-09-22The 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 274 square meters per square second, 0 to 6 km bulk shear 56 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
2043 J/kg
Mixed-layer CIN
-38 J/kg
Surface CAPE
2905 J/kg
Mixed-layer LCL
1714 m above ground
0-6 km bulk shear
56 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
274 m²/s²
0-3 km storm-relative helicity
406 m²/s²
Significant tornado parameter
1.2
Supercell composite
9.6
0-3 km lapse rate
6.9 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 12:00Z

11.9 hours after it, 37 km from the path. September 22, 2005.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2005-09-22Temperature 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 -25385, lifted condensation level 976 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 2005-09-22The 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 -111 square meters per square second, 0 to 6 km bulk shear 48 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
-25385 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
976 m above ground
0-6 km bulk shear
48 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
-111 m²/s²
0-3 km storm-relative helicity
258 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

Minneapolis - Crystal (MIC), 7 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:53 UTC8571140° 7 kt1004.1
23:53 UTC8466140° 12 kt1001.7VCTS
00:07 UTC80.664.4280° 34 kt561006.1TS HZ SQ
00:10 UTC69.864.4290° 30 kt561006.1+TSRA SQ
00:13 UTC66.262.6300° 42 kt591005.4+TSRA BR SQ
00:16 UTC64.462.6320° 40 kt591003.7+TSRA FG
00:24 UTC66.264.4330° 28 kt581005.1TS BR
00:27 UTC66.264.4350° 32 kt541005.1+TSRA BR
00:31 UTC66.264.4360° 15 kt421005.8TSRA BR
00:34 UTC66.266.2360° 17 kt381005.4+TSRA BR
00:53 UTC6867360° 13 kt271006.4+TSRA BR
01:01 UTC6866.2360° 4 kt181006.4TSRA BR
01:06 UTC6868 5 kt1006.8-TSRA
01:27 UTC69.866.2140° 6 kt1005.8
01:38 UTC6866.2120° 8 kt1006.1TS
01:53 UTC696750° 10 kt1007.5-TSRA

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

The radar

The Minneapolis radar (KMPX), 35 km away, was scanning. The volume nearest the touchdown began at 00:07 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
23:28 UTCHAIL 0.753 N Big LakeSherburne, MN
23:30 UTCTSTM WND DMGBig LakeSherburne, MNSEVERAL TREES WERE DOWNED.
23:30 UTCHAIL 0.75Big LakeSherburne, MNROOF AND SIDING DAMAGED.
23:32 UTCHAIL 0.75BeckerSherburne, MN
23:36 UTCTSTM WND GST 67MonticelloWright, MN11 INCH BRANCHES DOWN. SIDING OFF HOMES.
23:36 UTCHAIL 0.75Big LakeSherburne, MNFELL FOR 8 MINUTES
23:38 UTCHAIL 1MonticelloWright, MN
23:41 UTCTSTM WND GST 67MonticelloWright, MN
23:44 UTCHAIL 2MonticelloWright, MN
23:46 UTCTSTM WND DMGElk RiverSherburne, MNTREES DOWNED ACROSS COUNTY ROAD 15. TREE ON HOUSE NEAR ELEMENTARY SCHOOL.
23:46 UTCHAIL 0.75Elk RiverSherburne, MNTREES DOWNED ACROSS COUNTY ROAD 15. TREE ON HOUSE NEAR ELEMENTARY SCHOOL.
23:46 UTCHAIL 0.88Elk RiverSherburne, MN
23:47 UTCTSTM WND GST 58St MichaelWright, MN
23:47 UTCHAIL 0.88St MichaelWright, MN
23:50 UTCTSTM WND DMGRogersHennepin, MNAPARTMENT BUILDING WALLS BLOWN IN.
23:50 UTCTSTM WND DMGRogersHennepin, MNAPARTMENT BUILDING WALLS BLOWN IN ON HWY 101 ON NORTHEAST SIDE OF TOWN
23:50 UTCHAIL 1.54 S RogersHennepin, MN
23:52 UTCHAIL 0.75MonticelloWright, MN
23:53 UTCHAIL 1.75St MichaelWright, MN
23:56 UTCHAIL 0.75HanoverHennepin, MN
23:57 UTCHAIL 0.75OtsegoSherburne, MN
23:58 UTCHAIL 0.75RamseyAnoka, MNHAILED FOR 5 MINUTES
23:58 UTCHAIL 1.75RogersHennepin, MN
23:58 UTCHAIL 2.5AndoverAnoka, MN
23:59 UTCHAIL 0.88DaytonHennepin, MN
00:00 UTCHAIL 0.75RamseyAnoka, MN
00:00 UTCHAIL 0.75RamseyAnoka, MN
00:02 UTCTSTM WND DMGBrooklyn CenterHennepin, MNMANY TREES UP TO 3 FEET IN DIAMETER TREE DOWNED. ONE TREE DOWN ON ROOF OF HOME. ANOTHER TREE FELL IN KITCHEN OF HOME.
00:02 UTCHAIL 0.88DaytonHennepin, MN
00:03 UTCTSTM WND DMGAndoverAnoka, MNTHREE HOUSES DESTROYED...PEOPLE TRAPPED IN DAMAGED HOUSES.
00:03 UTCTORNADOAndoverAnoka, MNTHREE HOUSES SIGNIFICANTLY DAMAGED. OTHER HOMES...A SHED...AND GARAGES DAMAGED. MANY LARGE TREES DOWNED. CANOE THROWN 2 BLOCKS. SOME DAMAGE FROM DOWNBURST WINDS. SOME DAMAGE FROM TORNADO.
00:04 UTCTSTM WND DMGAndoverAnoka, MN3 FOOT DIAMETER TREE DOWN.
00:04 UTCTSTM WND DMGAndoverAnoka, MNSEVERAL TREES UP TO 3 FOOT DIAMETER DOWNED.
00:04 UTCHAIL 0.75Maple GroveHennepin, MN
00:04 UTCTORNADOAndoverAnoka, MNSEVERAL TREES UP TO 3 FOOT DIAMETER AND POWER LINES WERE DOWNED. WORST DAMAGE ON SOUTHERN AND EASTERN SIDE OF TOWN JUST NORTH OF BUNKER HILLS REGIONAL PARK. HOMES AND GARAGES DAMAGED. SOME DAMAGE FROM WIDESPREAD DOWNBURS
00:05 UTCHAIL 0.75Maple GroveHennepin, MN
00:06 UTCHAIL 1Maple GroveHennepin, MN
00:07 UTCTSTM WND DMGBrooklyn CenterHennepin, MN3 FOOT DIAMETER TREE DOWN ON TOP OF HOUSE.
00:07 UTCTSTM WND DMGBrooklyn ParkHennepin, MNGODFATHERS PIZZA WALL BLOWN IN.
00:07 UTCTSTM WND DMGBrooklyn ParkHennepin, MNGODFATHERS PIZZA WALL BLOWN IN. THREE INCH DIAMETER TREES DOWNED.

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

This ground now

The live radar over the trackEvery 2005 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of September 21, 2005

3 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
September 216:22 PM CDTF0Kandiyohi, MN0.120
September 217:16 PM CDTF0Anoka, MN0.325
September 217:16 PM CDTF2Anoka, MN2.0501

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.