Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 92, NWS Grand Forks, ND

August 9, 20214 counties in Minnesota; Grand Forks County, Traill County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 9, 2021, 10:42 PM CDT for 4 counties in Minnesota; Grand Forks County, Traill County, North Dakota. It was in force for 63 min. 15 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 9, 2021, 10:42 PM CDT (03:42 UTC)
Expired: Aug 9, 2021, 11:45 PM CDT
In force: 63 min
Issued by: NWS Grand Forks, ND
Area: Storm-based polygon
Tornado: Possible
Damage threat: Considerable
Hail: 1.0 in
Wind: 70.0 mph

Counties Norman County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Grand Forks County, ND, Traill County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 53 km from the middle of the area, began a volume at 03:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Aug 9, 10:42 PM CDT	TSTM WND DMG	1 S Grand Forks, ND	NUMEROUS LARGE BRANCHES AND LIMBS DOWN ALONG BELMONT, SOUTH OF 27TH.
Aug 9, 10:44 PM CDT	TSTM WND GST 60	2 N East Grand Forks, MN	PEAK WIND MEASURED AT A PERSONAL WEATHER STATION.
Aug 9, 10:45 PM CDT	TSTM WND DMG	2 Wnw Grand Forks, ND	METAL ROOF TORN OFF OF A BUSINESS ALONG U.S. HIGHWAY 2. TIME ESTIMATED BASED ON RADAR AND NEARBY SENSOR OBSERVATIONS.
Aug 9, 10:46 PM CDT	TSTM WND DMG	3 Ese Reynolds, ND	A FEW LARGE 3 TO 5 INCH DIAMETER TREE BRANCHES DOWN IN SHELTER BELTS ACROSS NORTHERN STAVANGER TOWNSHIP. TIME ESTIMATED BASED ON RADAR.
Aug 9, 10:47 PM CDT	TSTM WND DMG	4 Ne Reynolds, ND	LARGE 4 TO 6 INCH DIAMTER ASH TREE BRANCHES BROKEN DOWN IN A FARMSTEAD.
Aug 9, 10:48 PM CDT	TSTM WND GST 62	4 Nnw Grand Forks, ND	PEAK WIND MEASURED AT AN NDDOT RWIS STATION.
Aug 9, 10:49 PM CDT	TSTM WND DMG	4 N East Grand Forks, MN	PICTURE RECEIVED OF ROOF DAMAGE TO A FARM BUILDING VIA SOCIAL MEDIA. TIME ESTIMATED FROM RADAR.
Aug 9, 10:49 PM CDT	TSTM WND DMG	4 N East Grand Forks, MN	PICTURE RECEIVED OF ROOF DAMAGE TO A FARM BUILDING. VIA SOCIAL MEDIA. TIME ESTIMATED FROM RADAR.
Aug 9, 10:49 PM CDT	TSTM WND DMG	4 N East Grand Forks, MN	STEEL PANELS TORN OFF A POLESHED. LARGE TREE BRANCHES DOWN AROUND THE ARAE. PHOTO AND REPORT POSTED VIA SOCIAL MEDIA. TIME ESTIMATED BASED ON RADAR AND NEARBY WIND SENSOR REPORTS.
Aug 9, 10:55 PM CDT	TSTM WND GST 56	5 Ene East Grand Forks, MN	PEAK WIND MEASURED AT A PERSONAL WEATHER STATION.
Aug 9, 10:55 PM CDT	TORNADO 1	1 S Davidson, MN	A TORNADO TRACKED FOR ABOUT 3 MILES TO AROUND 5 NNE OF FISHER BY 1101 PM CDT. THE TORNADO BLEW OUT TWO WALLS OF A POLESHED, BROKE DOWN SEVERAL ASH AND COTTONWOOD TREES, AND PEELED UP TIN SIDING ON OTHER FARM BUILDING IN A YARD. IT CARRIED DEBRIS TO THE EAST AN
Aug 9, 11:05 PM CDT	TORNADO 0	4 Se Key West, MN	A TORNADO TRACKED INTERMITTENTLY TO THE EAST-NORTHEAST FOR ROUGHLY 2 MILES TO AROUND 5SE KEY WEST BY 1109 PM CDT. THE TORNADO SNAPPED THE TOPS OFF OF SEVERAL ASH AND COTTONWOOD TREES AT TWO FARMSTEADS ALONG ITS PATH AND CRACKED A POWER POLE. PEAK WINDS ESTIMAT
Aug 9, 11:31 PM CDT	TSTM WND DMG	3 Nne Dorothy, MN	PICTURE RECEIVED OF DOWNED LARGE TREE, WITH REPORT OF ADDITIONAL TREES DAMAGE AROUND THE AREA. TIME ESTIMATED FROM RADAR. REPORT VIA SOCIAL MEDIA.
Aug 9, 11:31 PM CDT	TSTM WND DMG	3 Nne Dorothy, MN	PICTURE RECEIVED OF LARGE TREE DOWN, WITH REPORT OF ADDITIONAL TREES DAMAGE AROUND THE AREA. TIME ESTIMATED FROM RADAR. REPORT VIA SOCIAL MEDIA.
Aug 9, 11:31 PM CDT	TSTM WND DMG	3 Nne Dorothy, MN	SEVERAL LARGE TREES BLOWN DOWN, ALONG WITH NUMEROUS LARGE TREE BRANCHES AND LIMBS. REPORT AND PHOTOS POSTED VUA SOCIAL MEDIA. TIME ESTIMATED BASED ON RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 9, 4:01 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

International Fa, MN (KINL), launched 00:00Z, 3.7 hours before the alert went out and 271 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

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.

Mixed-layer CAPE: 1281 J/kg
Mixed-layer CIN: -95 J/kg
Mixed-layer LCL: 1326 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 220 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 5.0

Open this sounding in Storm Lab

The text

As transmitted.

689 
WUUS53 KFGF 100342
SVRFGF
MNC107-113-119-125-NDC035-097-100445-
/O.NEW.KFGF.SV.W.0092.210810T0342Z-210810T0445Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Forks ND
1042 PM CDT Mon Aug 9 2021

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Northwestern Red Lake County in northwestern Minnesota...
  Northwestern Norman County in northwestern Minnesota...
  Western Polk County in northwestern Minnesota...
  Western Pennington County in northwestern Minnesota...
  Eastern Grand Forks County in northeastern North Dakota...
  Northern Traill County in southeastern North Dakota...

* Until 1145 PM CDT.

* At 1041 PM CDT, severe thunderstorms were located along a line
  extending from 6 miles east of Manvel to near Thompson to near
  Mayville, moving east at 20 mph.

  HAZARD...70 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Severe thunderstorms will be near...
  Bygland around 1055 PM CDT.
  Mallory around 1100 PM CDT.

Other locations in the path of these severe thunderstorms include
Tabor, Cummings, Davidson, Fisher, Hillsboro and Sherack.

This includes Interstate 29 between mile markers 103 and 150.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4817 9641 4779 9642 4736 9645 4740 9738
      4777 9726 4815 9712
TIME...MOT...LOC 0341Z 267DEG 17KT 4809 9703 4778 9704 4747 9728 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

TG

2 follow-up statements

880 
WWUS53 KFGF 100357
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
1057 PM CDT Mon Aug 9 2021

MNC107-113-119-125-NDC035-097-100445-
/O.CON.KFGF.SV.W.0092.000000T0000Z-210810T0445Z/
Red Lake MN-Norman MN-Polk MN-Pennington MN-Grand Forks ND-Traill ND-
1057 PM CDT Mon Aug 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 PM CDT
FOR NORTHWESTERN RED LAKE...NORTHWESTERN NORMAN...WESTERN POLK...
WESTERN PENNINGTON...SOUTHEASTERN GRAND FORKS AND NORTHEASTERN TRAILL
COUNTIES...

At 1056 PM CDT, severe thunderstorms were located along a line
extending from near Tabor to Fisher to near Cummings, moving east at
30 mph.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

These severe storms will be near...
  Fisher, Sherack and Eldred around 1100 PM CDT.

Other locations in the path of these severe thunderstorms include
Angus, Crookston, Shelly, Nielsville, Harold, Gentilly, Carpenters
Corner and Huot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4817 9641 4779 9642 4736 9645 4739 9706
      4778 9705 4815 9702
TIME...MOT...LOC 0356Z 267DEG 27KT 4810 9679 4779 9680 4748 9704 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

TG

167 
WWUS53 KFGF 100413
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
1113 PM CDT Mon Aug 9 2021

MNC107-NDC035-097-100422-
/O.CAN.KFGF.SV.W.0092.000000T0000Z-210810T0445Z/
Norman MN-Grand Forks ND-Traill ND-
1113 PM CDT Mon Aug 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN NORMAN...
SOUTHEASTERN GRAND FORKS AND NORTHEASTERN TRAILL COUNTIES IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 4817 9641 4779 9642 4773 9642 4770 9683
      4781 9687 4815 9687
TIME...MOT...LOC 0412Z 258DEG 33KT 4815 9655 4784 9656 4769 9669 

$$

MNC113-119-125-100445-
/O.CON.KFGF.SV.W.0092.000000T0000Z-210810T0445Z/
Red Lake MN-Polk MN-Pennington MN-
1113 PM CDT Mon Aug 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 PM CDT
FOR NORTHWESTERN RED LAKE...NORTHWESTERN POLK AND WESTERN PENNINGTON
COUNTIES...

At 1112 PM CDT, severe thunderstorms were located along a line
extending from near Carpenters Corner to near Crookston to near
Eldred, moving east at 35 mph.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
  Carpenters Corner, Huot, Dorothy and Gentilly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4817 9641 4779 9642 4773 9642 4770 9683
      4781 9687 4815 9687
TIME...MOT...LOC 0412Z 258DEG 33KT 4815 9655 4784 9656 4769 9669 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

TG

The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 9, 9:54 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Polk	66 min
Aug 9, 11:05 PM CDT	Tornado Warning	FGF	Polk	25 min
Aug 9, 11:29 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Marshall, Pennington, Polk, Red Lake	61 min
Aug 10, 2:20 AM CDT	Special Weather Statement	FGF	Lake of the Woods	25 min
Aug 10, 2:55 AM CDT	Special Weather Statement	FGF	Lake of the Woods	35 min
Aug 9, 7:04 PM CDT	Severe Thunderstorm Warning	FGF	Cavalier, Ramsey, Towner	56 min
Aug 9, 7:11 PM CDT	Tornado Warning	FGF	Cavalier, Ramsey, Towner	34 min
Aug 9, 7:29 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Eddy, Griggs, Nelson	46 min
Aug 9, 7:57 PM CDT	Severe Thunderstorm Warning	FGF	Cavalier, Pembina, Ramsey, Walsh	63 min
Aug 9, 8:08 PM CDT	Severe Thunderstorm Warning	FGF	Grand Forks, Nelson	27 min
Aug 9, 8:12 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Eddy, Griggs, Nelson	63 min
Aug 9, 8:28 PM CDT	Tornado Warning	FGF	Griggs, Nelson	32 min
Aug 9, 8:52 PM CDT	Severe Thunderstorm Warning	FGF	Cavalier, Pembina	38 min
Aug 9, 9:09 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Grand Forks, Griggs, Nelson, Steele	66 min
Aug 9, 9:20 PM CDT	Tornado Warning	FGF	Grand Forks, Nelson, Steele	40 min
Aug 9, 9:42 PM CDT	Tornado Warning	FGF	Grand Forks	48 min
Aug 9, 10:08 PM CDT	Special Weather Statement	FGF	Pembina	52 min
Aug 9, 10:30 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Grand Forks, Steele, Traill	30 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2021 Severe Thunderstorm Warnings in North Dakota, 2021 Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.