A negatively tilted trough and associated cold front pushed across the CWA on the morning of June 11th. Severe thunderstorms developed along the pre-frontal trough, as well as the cold front.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS FGF wrote it up.
A negatively tilted trough and associated cold front pushed across the CWA on the morning of June 11th. Severe thunderstorms developed along the pre-frontal trough, as well as the cold front. Numerous wind damage, and hail reports were submitted, as well as a tornado.
The local office's own words before the first event, 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 first event at Jun 11, 2:05 AM CST, 2 hours 10 minutes earlier.
Area Forecast Discussion National Weather Service Grand Forks ND 305 AM CDT Fri Jun 11 2021 .SHORT TERM...(Today through Saturday) Issued at 305 AM CDT Fri Jun 11 2021 The main forecast challenge is the severe weather potential early this morning. A severe thunderstorms watch has already been issued for eastern North Dakota and some adjacent counties of northwest and west central Minnesota until 7 am. As of about 3 am, surface low pressure was located somewhere between Bismarck and Minot, with a warm front extending out to the east-southeast from it, to somewhere over southeast North Dakota. Temperatures were still very mild, with 86 degrees still being reported at both Aberdeen SD and Gwinner ND. Fargo was reporting a dewpoint of 70, as was Detroit Lakes MN. The SPC mesoanalysis page showed a nice low level jet punching up through the central Dakotas, but the best 0-6km bulk shear lags behind the line of storms from east of Minot to east of Bismarck. These storms have a history of producing some damaging wind gusts, but overall they have mainly been below 50 knots. The main question is what happens as these storms move into eastern North Dakota. There was a trend yesterday evening with more of the high resolution models showing the current storms continuing to move east, but the stronger storms diving more into South Dakota. The latest HRRR shows the line of storms moving into the Red River Valley by sunrise, but nothing too exciting. The HREF from 12z yesterday showed the 4hr neighborhood probability of severe wind moving toward eastern ND and basically dropping off to nothing. The SPC 3hr calibrated severe thunderstorm graphic shows the best values through 12z dropping toward the ND/SD border, then dropping off to nothing thereafter. This is the reason the severe thunderstorm watch goes until 12z. The line of storms looks to weaken pretty quickly after 12z as the storms cross the Red River, and they may die off sometime later this morning. The rest of the day will feature increasing west winds and much cooler temperatures. Quiet weather tonight into Saturday as well. .LONG TERM...(Saturday night through Thursday) Issued at 305 AM CDT Fri Jun 11 2021 An amplifying upper ridge on Sunday will keep impacts to the minimum during the long term period. The best opportunity for summer impacts could be Wednesday with hot temperatures, but at the current time strong mixing from southerly winds will keep RH values low and heat indices in check. Zonal flow at the beginning of the long term period quickly amplifies with an upper ridge extending from AZ into Alb/Sask, with upper lows off the Pacific NW coast and over the Hudson Bay. The ridging will be in place for the first half of the work week, with highs in the 80s and 90s. The high temperatures peak Wednesday with eastern North Dakota reaching the mid to upper 90s. Gusty south winds will result in mixing sufficient to keep RH values in the 20s and heat advisory potential minimal. NAEFS climatological percentiles are maxed out over western and central ND, giving me good confidence in a hot summer day. The Pacific upper low moves into Manitoba by Thursday, increasing chances for precipitation Thursday afternoon. Slightly cooler air will follow the late week system with Day 7 temperatures looking to be in the 70s and 80s. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1139 PM CDT Thu Jun 10 2021 Aviation concern still focused on eventual arrival of thunderstorm activity during the first 6hr of the TAF period. Strong to severe storms will be possible once this arrives in eastern ND with showers/weaker thunder favored in MN. Arrival right now looks to be first at KDVL by 09Z and closer to 12Z at KGFK/KFAR. Eventually prevailing dry conditions should return Friday, though it could be delayed if there is redevelopment of showers/storms during the daytime period (hard to say at this point). IFR or lower conditions will be possible with stronger thunderstorm activity. Southwest to west winds increase behind the cold front during the day Friday and gusts in excess of 30kt appear likely in eastern ND (strongest at KDVL). These should decrease with sunset, though gusty winds may linger a KDVL into Friday night. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. SHORT TERM...Godon LONG TERM...Speicher AVIATION...DJR
Hazardous Weather Outlook National Weather Service Grand Forks ND 314 AM CDT Fri Jun 11 2021 MNZ001>003-029-NDZ006>008-014>016-024-026>030-038-039-049-052>054- 120815- West Polk-Norman-Clay-Wilkin-Towner-Cavalier-Pembina-Benson- Ramsey-Eastern Walsh-Eddy-Nelson-Grand Forks-Griggs-Steele-Traill- Barnes-Cass-Ransom-Sargent-Richland-Western Walsh- 314 AM CDT Fri Jun 11 2021 This hazardous weather outlook is for portions of eastern North Dakota, west central and northwest Minnesota. .DAY ONE...Today and Tonight Scattered thunderstorms are possible through the early morning hours. Some of these storms may be severe with damaging wind gusts up to 75 mph and 1 inch diameter hail. .DAYS TWO THROUGH SEVEN...Saturday through Thursday The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to contact the National Weather Service with any severe weather reports. MNZ004>009-013>017-022>024-027-028-030>032-040-120815- 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-West Otter Tail-East Otter Tail-Wadena-Grant- 314 AM CDT Fri Jun 11 2021 This hazardous weather outlook is for portions of west central and northwest Minnesota. .DAY ONE...Today and Tonight Scattered thunderstorms are possible east of the Red River around or after 6 am. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Saturday through Thursday The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS ND
453 AM CDT FRI JUN 11 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0422 AM TSTM WND GST CLYDE 48.77N 98.90W
06/11/2021 M63 MPH CAVALIER ND MESONET
63 MPH GUST IN CLYDE ND FROM NDAWN.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS ND
454 AM CDT FRI JUN 11 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0425 AM TSTM WND GST 3 NW EDMORE 48.44N 98.50W
06/11/2021 M59 MPH RAMSEY ND MESONET
NDAWN REPORTED 59MPH GUST IN 3NW OF EDMORE
ND.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS ND
455 AM CDT FRI JUN 11 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0425 AM TSTM WND GST GWINNER 46.22N 97.66W
06/11/2021 M59 MPH SARGENT ND AWOS
59MPH GUST IN GWINNER AP ND FROM AWOS.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS ND
500 AM CDT FRI JUN 11 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0456 AM TSTM WND GST 2 E MAYVILLE 47.50N 97.29W
06/11/2021 M58 MPH TRAILL ND MESONET
58 MPH GUST REPORTED BY NDAWN 2E OF MAYVILLE
ND.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS ND
503 AM CDT FRI JUN 11 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0440 AM TSTM WND GST 5 NE HOPE 47.37N 97.64W
06/11/2021 M57 MPH STEELE ND MESONET
MESONET STATION 321686 HOPE ND 5 NE.
&&
APPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS ND
504 AM CDT FRI JUN 11 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0440 AM TSTM WND GST 2 E LOGAN CENTER 47.80N 97.77W
06/11/2021 M56 MPH GRAND FORKS ND MESONET
MESONET STATION 325332 LOGAN CENTER ND 2 E.
&&
APThe Fargo/Grand Forks radar (KMVX), 86 km away, was scanning. The volume nearest the first event began at 10:16 UTC.
9 thunderstorm wind, 1 tornado. Local standard time, as filed.
Large tree branches and limbs broken down on vehicles. Report and photos posted via social media.
Peak wind measured at an NDAWN station.
Five trees blown down in a yard, one partially uprooted. Time estimated based on radar.
Peak wind was measured at a Minnesota DOT RWIS station.
Several large tree branches were snapped.
A tall, two stall garage was collapsed by the wind. Several trees were snapped or uprooted in the surrounding area. Time based on radar.
Large tree branches were broken, with diameters of 6 to 8 inches.
Peak wind gust of 67 mph measured at a personal weather station.
A dock, pontoon, and lift were flipped. Time is estimated based on radar data.
Video of the tornado was relayed via social media broadcast partner.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2021Every state in 2021This day in weather historyThe tornado archive for Minnesota, 2021Warnings in Minnesota, June 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 969903, 969911, 969905, 969913, 969906, 969907, 969909, 969914, 969910, 969902.