Tornadoes · United States · Minnesota · 2017

EF2 tornado, Wheatville to Ulen, Minnesota, July 11, 2017

Name: EF2 tornado, Wheatville to Ulen, Minnesota, July 11, 2017
Start: 2017-07-12T01:42:00.000Z
End: 2017-07-12T02:06:00.000Z
Location: Wheatville to Ulen, Minnesota

From Wheatville to Ulen, this EF2 tornado ran 12.8 miles across Norman and Clay counties on July 11, 2017, touching down at 8:42 PM CDT and reaching 500 yards wide. It killed nobody, and did $475,000 of property damage.

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.

EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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: EF2
Date: July 11, 2017
Touchdown: 8:42 PM CDT (01:42 UTC)
Lifted: 9:06 PM CDT (02:06 UTC)
On the ground: 24 minutes
Path length: 12.8 miles (20.6 km)
Path width: 500 yards (457 m)
Deaths: 0
Injuries: 0
Property damage: $475,000
Crop damage: $450,000
Counties: Norman and Clay counties
Touchdown point: 47.220, -96.510
Lift-off point: 47.109, -96.270
Record number: 1707111942-01

The damage survey

3 damage points were recorded along this path by NWS FGF, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 130 mph.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

After morning showers moved through eastern North Dakota and northwest Minnesota, clouds decreased and allowed for some decent afternoon warming. Highs warmed into the low 90s over all of east central and southeast North Dakota, along with dew point values in the lower 70s. Thunderstorms formed a little later than initially thought, partly due to the morning clouds. The storms initially formed over northeast North Dakota during the late afternoon, but expanded east and southeast throughout the evening. These storms produced large hail, strong winds, and multiple tornadoes. One of the tornadoes had a particularly long track, taking it from just north of the Mayville radar site to just northeast of Hillsboro.

This tornado collapsed at least one shed, snapped numerous trees, and tossed large round hay bales across a sugar beet field. It also snapped at least a half dozen wooden power poles. Peak winds were estimated at 125 mph. The tornado continued into Clay County, where it ended two miles north of Ulen, at 806 pm CST.

This tornado began at 742 pm CST, 3 miles north of Borup, in Norman County. This tornado collapsed at least one shed, snapped numerous trees, and tossed large round hay bales across a sugar beet field. It also snapped at least a half dozen wooden power poles. Peak winds were estimated at 125 mph.

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

What forecasters said that day

The local office's own words before the tornado touched down, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Grand Forks, ND wrote its last area forecast discussion before the tornado touched down at Jul 11, 7:09 PM CDT, 1 hour 33 minutes earlier.

Area forecast discussion, Jul 11, 7:09 PM CDT, 1 hour 33 minutes before

Area Forecast Discussion
National Weather Service Grand Forks ND
709 PM CDT Tue Jul 11 2017

.UPDATE...
Issued at 708 PM CDT Tue Jul 11 2017

continued severe.  no changes.

&&

.SHORT TERM...(This evening through Wednesday)
Issued at 350 PM CDT Tue Jul 11 2017

Broad upper level trough was over southern Canada. Upper
trough will slowly shift east of the area by 12Z Thu.
Upper level ridging will commence thereafter over the
Rockies. Water vapor loop indicated an upper level jet
nosing into ND with showers mainly over northern MN for
the afternoon.

Now waiting for storms to develop late this afternoon.
Highest mixed layer capes were around 3500 j/kg over
eastern ND with LI's around -6. Precipitable water
was around an inch and a half. Mixed layer CIN was
falling below 50 over central and southeast ND.
Convective temps ranged from 90 to 95 degrees in the
western zones. Surface trough extended north-south
over eastern ND. Expect storms to develop over the
next couple hours.

Upper level low pressure system over the area will
produce showers over northern MN for Wed.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 350 PM CDT Tue Jul 11 2017

In the wake of the system crossing the area, expect some lingering
showers, mainly over northwest MN. Northerly flow behind the system
will pull some cooler air out of Canada limiting high temperatures
to around the 70 degree mark. The upper ridge quickly rebounds by
Thursday, with high temperatures working their way back into the
80s, with near 90 degree temps by Friday.

For Saturday...Guidance indicates another wave crossing the area
bringing chances for another round of showers or storms, with a
slight cool down in its wake for Sunday.

Otherwise, the upper level pattern looks to remain progressive
through the end of the period, with a series of impulses crossing
the area. Expect more chances for precipitation as the impulses
propagate through the flow, and high temperatures are forecast to
remain generally in the mid to upper 80s, and lows in the upper 50s
to lower 60s. Look for a mix of sun and clouds through the rest of
the period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 708 PM CDT Tue Jul 11 2017

storms in the GFK area now and may impact TVF too. Fargo area is
very iffy as storms may fire quickly. Otherwise mvfr cigs may drop
south into at least nrn fcst area late tonight/Wed AM.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&

UPDATE...Riddle
SHORT TERM...JH
LONG TERM...Hopkins
AVIATION...Riddle

Hazardous weather outlook, Jul 11, 11:50 AM CDT, 8 hours 52 minutes before

Hazardous Weather Outlook
National Weather Service Grand Forks ND
1150 AM CDT Tue Jul 11 2017

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-121200-
West Polk-Norman-Clay-Kittson-Roseau-Lake Of The Woods-
West Marshall-East Marshall-North Beltrami-Pennington-Red Lake-
East Polk-North Clearwater-South Beltrami-Mahnomen-
South Clearwater-Hubbard-West Becker-East Becker-Wilkin-
West Otter Tail-East Otter Tail-Wadena-Grant-Towner-Cavalier-
Pembina-Benson-Ramsey-Eastern Walsh County-Eddy-Nelson-
Grand Forks-Griggs-Steele-Traill-Barnes-Cass-Ransom-Sargent-
Richland-Western Walsh County-
1150 AM CDT Tue Jul 11 2017

This hazardous weather outlook is for portions of eastern North
Dakota, west central and northwest Minnesota.

.DAY ONE...This Afternoon and Tonight

Scattered to numerous severe thunderstorms are possible across
the region during the late afternoon and evening hours. This is a
slight delay in timing to the original thinking. The highest risk
will be across west central Minnesota where coverage will be
greater, although severe storms are possible everywhere. Hail to
over 2 inches in diameter, damaging wind gusts to around 75 mph,
tornadoes, and localized heavy rain are the main threats.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is expected this afternoon and evening.

In the hours before

Local storm report, Jul 11, 7:46 PM CDT, 56 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
746 PM CDT TUE JUL 11 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0632 PM     HAIL             1 W NORTHCOTE           48.85N 97.02W
07/11/2017  E1.00 INCH       KITTSON            MN   LAW ENFORCEMENT

            DIME TO QUARTER SIZED HAIL FELL WEST OF NORTHCOTE

&&

BP

Local storm report, Jul 11, 7:58 PM CDT, 44 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
758 PM CDT TUE JUL 11 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0754 PM     FUNNEL CLOUD     3 NE EUCLID             48.00N 96.59W
07/11/2017                   POLK               MN   TRAINED SPOTTER

            PERSISTENT ALL CLOUD WITH POSSIBLE FUNNEL.

&&

GGUST

Local storm report, Jul 11, 8:00 PM CDT, 42 minutes before

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Local storm report, Jul 11, 8:05 PM CDT, 37 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
805 PM CDT TUE JUL 11 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0803 PM     HAIL             1 NNW HILLSBORO         47.42N 97.07W
07/11/2017  E1.75 INCH       TRAILL             ND   STORM CHASER

&&

GGUST

Local storm report, Jul 11, 8:11 PM CDT, 31 minutes before

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Local storm report, Jul 11, 8:27 PM CDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
827 PM CDT TUE JUL 11 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 PM     TSTM WND GST     7 SE HILLSBORO          47.33N 96.96W
07/11/2017  M79 MPH          TRAILL             ND   MESONET

            NDAWN PEAK GUST

&&

BP

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

1.7 hours before the tornado, 278 km from the path. July 12, 2017.

Skew-T log-p

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.

Hodograph

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: -83053 J/kg
Surface CAPE: 0 J/kg
Mixed-layer LCL: 841 m above ground
0-6 km bulk shear: 45 kt
0-1 km bulk shear: 26 kt
0-1 km storm-relative helicity: 374 m²/s²
0-3 km storm-relative helicity: 636 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0
0-3 km lapse rate: 4.8 K/km

Open this sounding in Storm Lab

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

10.3 hours after it, 278 km from the path. July 12, 2017.

Skew-T log-p

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.

Hodograph

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: 0 J/kg
Surface CAPE: 0 J/kg
Mixed-layer LCL: 543 m above ground
0-6 km bulk shear: 38 kt
0-1 km bulk shear: 25 kt
0-1 km storm-relative helicity: 267 m²/s²
0-3 km storm-relative helicity: 402 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2
0-3 km lapse rate: 4.0 K/km

Open this sounding in Storm Lab

The surface observations

Mahnomen (3N8), 36 km from the path, in the two hours either side.

Time (UTC)	Temp (°F)	Dew point (°F)	Wind	Gust (kt)	Pressure (mb)	Weather
00:00 UTC

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

The radar

The Fargo/Grand Forks radar (KMVX), 81 km away, was scanning. The volume nearest the touchdown began at 01:41 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 track Every 2017 tornado in Minnesota Every tornado in Minnesota since 1950 Warnings in force in Minnesota now The forecast where you are

The other tornadoes of July 11, 2017

12 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Damage
July 11	5:16 PM CDT	EF0	Towner, ND	2.0	150
July 11	5:35 PM CDT	EF1	Iowa, IA	4.6	60	$1,000
July 11	5:39 PM CDT	EF1	Walsh, ND	1.5	150	$2,000
July 11	6:45 PM EDT	EF0	Clarion, PA	1.0	250	$10,000
July 11	5:48 PM CDT	EF0	Cavalier, ND	0.4	100
July 11	5:51 PM CDT	EF0	Grand Forks, ND	1.0	100	$2,000
July 11	6:25 PM CDT	EF1	Grand Forks, ND	5.9	150	$2,000
July 11	6:30 PM CDT	EF1	Walsh, ND	7.0	150	$4,000
July 11	6:50 PM CDT	EF0	Grand Forks, ND	5.8	1,150
July 11	6:58 PM CDT	EF2	Traill, ND	22.0	1,200	$750,000
July 11	7:07 PM CDT	EF1	Polk, MN	10.0	250	$50,000
July 11	7:48 PM CDT	EF2	Traill, ND to MN	11.6	600	$800,000

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.