Tornadoes · United States · Minnesota · 2020

EF0 tornado, Park Rapids to Nevis, Minnesota, August 7, 2020

From Park Rapids to Nevis, this EF0 tornado ran 0.2 miles across Hubbard County on August 7, 2020, touching down at 7:30 PM CDT and reaching 25 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
August 7, 2020
Touchdown
7:30 PM CDT (00:30 UTC)
Lifted
7:32 PM CDT (00:32 UTC)
On the ground
2 minutes
Path length
0.2 miles (0.3 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Hubbard County
Touchdown point
46.930, -95.120
Lift-off point
46.930, -95.120
Record number
2008071830-01

What the Weather Service recorded

During the late afternoon and evening of Friday, August 7th, a warm front lifted through the northwest quarter of Minnesota. Thunderstorms fired up, and produced large hail, damaging wind gusts, and a few tornadoes.

A wall cloud produced a tornado with multiple brief touchdowns west of Fishhook Lake and near highway 71. Several trees were damaged. Peak winds were estimated at 70 mph.

This tornado was wrapped in heavy rain and downburst winds. It crossed portions of Shallow Lake, the north end of Lake Belle Taine, and the south end of Eighth Crow Wing Lake, where it snapped or uprooted numerous trees. Peak winds were estimated at 90 mph.

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

The warnings

9 minutes of warning. NWS FGF issued a tornado warning for this county at 00:21 UTC, 9 minutes before the tornado touched down, in force until 01:00 UTC.

The county was under a severe thunderstorm watch, issued at 20:54 UTC and running to 03:34 UTC.

Issued (UTC)ExpiredProductOffice
20:54 UTC03:34 UTCSevere Thunderstorm WatchFGF
22:30 UTC23:30 UTCSevere Thunderstorm WarningFGF
23:18 UTC00:03 UTCSevere Thunderstorm WarningFGF
00:21 UTC01:00 UTCTornado WarningFGF
00:53 UTC01:45 UTCTornado WarningFGF
01:47 UTC02:00 UTCSevere Thunderstorm WarningFGF
02:00 UTC03:00 UTCSevere Thunderstorm WarningFGF
15:39 UTC16:30 UTCSevere Thunderstorm WarningFGF
16:38 UTC17:30 UTCSevere Thunderstorm WarningFGF
17:27 UTC18:15 UTCSevere Thunderstorm WarningFGF
18:10 UTC18:54 UTCSevere Thunderstorm WarningFGF

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 19:34 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.

International Fa, MN (KINL), 00:00Z

0.5 hours before the tornado, 228 km from the path. August 8, 2020.

Skew-T log-pSkew-T log-p diagram, International Fa, MN at 00:00Z on 2020-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 677 joules per kilogram, CIN -42, lifted condensation level 1011 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, International Fa, MN at 00:00Z on 2020-08-08The 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 57 square meters per square second, 0 to 6 km bulk shear 6 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
677 J/kg
Mixed-layer CIN
-42 J/kg
Surface CAPE
1974 J/kg
Mixed-layer LCL
1011 m above ground
0-6 km bulk shear
6 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

International Fa, MN (KINL), 12:00Z

11.5 hours after it, 228 km from the path. August 8, 2020.

Skew-T log-pSkew-T log-p diagram, International Fa, MN at 12:00Z on 2020-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 675 joules per kilogram, CIN -99, lifted condensation level 690 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, International Fa, MN at 12:00Z on 2020-08-08The 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 75 square meters per square second, 0 to 6 km bulk shear 14 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
675 J/kg
Mixed-layer CIN
-99 J/kg
Surface CAPE
16 J/kg
Mixed-layer LCL
690 m above ground
0-6 km bulk shear
14 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.2 K/km

Open this sounding in Storm Lab

The radar

The Fargo/Grand Forks radar (KMVX), 179 km away, was scanning. The volume nearest the touchdown began at 00:28 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
22:05 UTCTSTM WND DMG8 Ese WaubunBecker, MNA COUPLE OF TREES BLOWN DOWN ALONG CR144. TIME ESTIMATED BASED ON RADAR.
22:27 UTCHAIL 1.2517 Wsw Lake ItascaClearwater, MNA FEW QUARTER TO HALF DOLLAR SIZED HAIL FELL ALONG HWY 113. TIME ESTIMATED BASED ON RADAR.
22:50 UTCHAIL 12 Sse Lake ItascaClearwater, MNNEAR THE MAIN LODGE.
22:50 UTCHAIL 1Lake ItascaClearwater, MN
23:25 UTCTSTM WND DMG3 Nnw Lake GeorgeHubbard, MNA FEW POPLAR TREES SNAPPED AROUND LAKE MINNIE. REPORT POSTED VIA SOCIAL MEDIA. TIME ESTIMATED BASED ON RADAR.
00:16 UTCFUNNEL CLOUD1 Nw PonsfordBecker, MNA PERSISTENT FUNNEL WITH A BRIEF NON-DAMAGING TOUCHDOWN WAS NOTED NEAR PINE POINT. VIDEO AND REPORT POSTED VIA SOCIAL MEDIA.
00:16 UTCFUNNEL CLOUD3 Wnw OsageBecker, MNA PERSISTENT FUNNEL WITH A BRIEF NON-DAMAGING TOUCHDOWN AT THE TREE TOP LEVEL WAS NOTED. VIDEO AND REPORT POSTED VIA SOCIAL MEDIA.
00:30 UTCTORNADO 03 Wnw Park RapidsHubbard, MNVIDEO AND SPOTTER REPORTS OF SUSTAINED WALL CLOUD WITH MULTIPLE FUNNELS AND MULTIPLE BRIEF TOUCHDOWNS OVER FEW MINUTE PERIOD WEST OF FISHHOOK LAKE AND NEAR HWY 71. SPOTTERS AND EMERGENCY MANAGEMENT REPORT SOME LARGE BRAN
00:30 UTCTORNADO1 Nnw Park RapidsHubbard, MNPOSSIBLE TORNADO TOUCHDOWN WEST SIDE OF FISHHOOK LAKE NEAR HWY 71. VIDEO AND NUMEROUS PICTURES WOULD INDICATE TOUCHDOWN, BUT IN ALL PICTURES THE VERY BOTTOM IS OBSCURED BY TREES. NO DAMAGE REPORTS HAVE BEEN RECEIVED.
00:35 UTCFUNNEL CLOUD1 Nw Park RapidsHubbard, MN
00:45 UTCTSTM WND DMG5 Nne Park RapidsHubbard, MNNUMEROUS TREES BLOWN DOWN ACROSS SOUTHERN EMMA TOWNSHIP FROM POTATOE LAKE INTO BIG SAND LAKE.
00:50 UTCHAIL 1.5DorsetHubbard, MN
01:05 UTCTORNADO 13 W NevisHubbard, MNA TORNADO LIKELY WRAPPED IN HEAVY RAIN AND DOWN BURST WINDS TRACKED FOR ROUGHLY 6 MILES TO AROUND 3 ESE OF NEVIS BY 825 PM CDT. IT CROSSED PORTIONS OF SHALLOW LAKE, THE NORTH END OF LAKE BELLE TAINE, AND THE SOUTH END OF
01:10 UTCHAIL 1.75NevisHubbard, MNNEAR LAKE BELLE TAINE
01:46 UTCTSTM WND GST 50ChamberlainHubbard, MNPEAK WIND MEASURED AT AN RWIS STATION NEAR CHAMBERLAIN.
01:50 UTCTSTM WND DMG2 Ene ChamberlainHubbard, MNA FEW TREES BLOWN DOWN ACROSS SOUTHEAST WHITE OAK TOWNSHIP.
02:20 UTCHAIL 1.754 Nw NevisHubbard, MNLARGE SPIKED HAILSTONES NEAR LOWER OJIBWAY LAKE. PHOTO AND REPORT POSATED VIA SOCIAL MEDIA. TIME ESTIMATED BASED ON RADAR.
02:50 UTCHAIL 1.252 Ene ChamberlainHubbard, MNQUARTER TO HALF DOLLAR IZED HAIL IN VERY HEAVY RAIN.

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

This ground now

The live radar over the trackEvery 2020 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of August 7, 2020

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 75:40 PM EDTEF1New Castle, DE4.2450
August 78:05 PM CDTEF1Hubbard, MN6.2250

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.