Tornadoes · United States · North Dakota · 2019

EF0 tornado, Calio, North Dakota, July 8, 2019

This EF0 tornado ran 3.1 miles across Cavalier County on July 8, 2019, touching down at 4:32 PM CDT and reaching 200 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
July 8, 2019
Touchdown
4:32 PM CDT (21:32 UTC)
Lifted
4:35 PM CDT (21:35 UTC)
On the ground
3 minutes
Path length
3.1 miles (4.9 km)
Path width
200 yards (183 m)
Deaths
0
Injuries
0
County
Cavalier County
Touchdown point
48.550, -98.940
Lift-off point
48.577, -98.886
Record number
1907081532-01

What the Weather Service recorded

By mid afternoon of July 8th, temperatures across eastern North Dakota and the northwest quarter of Minnesota had risen into the mid to upper 80s with dew points in the mid 60s to low 70s. A stationary boundary set up from west of Bismarck to near Rolla, North Dakota. Thunderstorms initially fired along this boundary, but as the evening wore on, the storms merged into lines, which tracked to the east-southeast. These storms mainly produced strong winds, but heavy rain was also reported in many areas. The Fargo-Moorhead area picked up quite a bit of rain in a short period of time, which resulted in flash flooding.

This tornado was likely wrapped in downburst winds and hail across portions of southwest Seivert Township, causing crop and tree damage. Peak winds were estimated at 85 mph.

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

The warnings

10 minutes of warning. NWS FGF issued a tornado warning for this county at 21:22 UTC, 10 minutes before the tornado touched down, in force until 22:00 UTC.

The county was under a severe thunderstorm watch, issued at 18:43 UTC and running to 00:43 UTC.

Issued (UTC)ExpiredProductOffice
18:43 UTC00:43 UTCSevere Thunderstorm WatchFGF
19:41 UTC20:15 UTCSevere Thunderstorm WarningFGF
19:53 UTC00:29 UTCFlash Flood WatchFGF
20:22 UTC21:15 UTCSevere Thunderstorm WarningFGF
21:11 UTC22:00 UTCSevere Thunderstorm WarningFGF
21:22 UTC22:00 UTCTornado WarningFGF
22:02 UTC03:00 UTCFlood AdvisoryFGF

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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:56 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.

Bismarck Municip, ND (KBIS), 12:00Z

9.5 hours before the tornado, 240 km from the path. July 8, 2019.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 12:00Z on 2019-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1630 joules per kilogram, CIN -203, lifted condensation level 1099 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, Bismarck Municip, ND at 12:00Z on 2019-07-08The 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 115 square meters per square second, 0 to 6 km bulk shear 24 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
1630 J/kg
Mixed-layer CIN
-203 J/kg
Surface CAPE
902 J/kg
Mixed-layer LCL
1099 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

Bismarck Municip, ND (KBIS), 00:00Z

2.5 hours after it, 240 km from the path. July 9, 2019.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 00:00Z on 2019-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1 joules per kilogram, CIN -584, lifted condensation level 1479 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, Bismarck Municip, ND at 00:00Z on 2019-07-09The 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 17 square meters per square second, 0 to 6 km bulk shear 39 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
1 J/kg
Mixed-layer CIN
-584 J/kg
Surface CAPE
228 J/kg
Mixed-layer LCL
1479 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.1 K/km

Open this sounding in Storm Lab

The radar

The Minot AFB radar (KMBX), 145 km away, was scanning. The volume nearest the touchdown began at 21:32 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
20:10 UTCHAIL 111 Ene RocklakeTowner, NDLARGE HAIL AND STRONG WINDS DAMAGED CROPS IN EAST CENTRAL LANSING TOWNSHIP. TIME ESTIMATED BASED ON RADAR.
21:06 UTCTORNADO 04 S NewvilleTowner, NDTRAINED SPOTTER LOCATED NORTH OF STARKWEATHER REPORTED BRIEF TORNADO TOUCHDOWN ROUGHLY 4 TO 5 MILES TO THEIR WEST NORTHWEST. THIS TORNADO LIKELY TRACKED FOR ONE QUARTER MILE OR LESS AND LIFTED BY 407 PM CDT. PEAK WINDS E
21:06 UTCTORNADO4 S NewvilleTowner, NDTRAINED SPOTTER LOCATED NORTH OF STARKWEATHER REPORTED BRIEF TORNADO TOUCHDOWN ROUGHLY 4 TO 5 MILES TO THEIR WEST NORTHWEST.
21:06 UTCTORNADO5 Wnw StarkweatherTowner, NDTRAINED SPOTTER REPORTED BRIEF TORNADO TOUCHDOWN.
21:32 UTCTORNADO 05 S CalioCavalier, NDA TORNADO WAS LIKELY WRAPPED IN DOWNBURST WINDS AND HAIL ACROSS A PORTIONS OF SOUTHWEST SEIVERT TOWNSHIP. MORE EXTREME CROP AND TREE DAMAGE INDICATED THE TORNADO TRACKED FOR ABOUT A MILES TO AROUND 4 SSE OF CALIO BY 4 35
21:35 UTCTSTM WND DMG5 S CalioCavalier, NDCROPS WERE LAID FLAT OVER ACROSS SOUTHERN SEIVERT TOWNSHIP A MUTIPLE ROUNDS OF LARGE HAIL, STRONG WINDS AND HEAVY RAINS BETWEEN 430 AND 5 PM CDT.
21:55 UTCTSTM WND GST 54LangdonCavalier, NDREPORT FROM LANGDON AWOS AT THE LANGDON AIRPORT.
22:01 UTCTSTM WND GST 631 E LangdonCavalier, NDNDAWN SENSOR - 10 M WIND.
23:00 UTCTSTM WND DMG3 Sse SouthamRamsey, NDA FEW LARGE BRANCHES BROKEN DOWN IN A SHELTER BELT.

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

This ground now

The live radar over the trackEvery 2019 tornado in North DakotaEvery tornado in North Dakota since 1950Warnings in force in North Dakota nowThe forecast where you are

The other tornadoes of July 8, 2019

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 81:52 PM CDTEF0Mercer, ND0.650
July 82:46 PM CDTEF0Sheridan, ND0.550
July 84:06 PM CDTEF0Towner, ND0.250
July 86:38 PM CDTEF0Adams, NE0.025

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.