Alert archive / North Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 80, NWS Grand Forks, ND

August 9, 2021Benson County, Eddy County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 9, 2021, 6:03 PM CDT for Benson County, Eddy County, North Dakota. It was in force for 57 min. 5 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, 6:03 PM CDT (23:03 UTC)
Expired
Aug 9, 2021, 7:00 PM CDT
In force
57 min
Issued by
NWS Grand Forks, ND
Area
Storm-based polygon
Damage threat
Considerable
Hail
1.75 in
Wind
70.0 mph

Counties Benson County, ND, Eddy County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 133 km from the middle of the area, began a volume at 23:07 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

TimeReportWhereRemark
Aug 9, 6:21 PM CDTHAIL 1.54 Ssw New Rockford, ND
Aug 9, 6:46 PM CDTTSTM WND DMG3 Nnw Brantford, NDBROKEN WINDOWS FROM VERY STRONG WINDS AND HAIL AT LEAST QUARTER SIZED.
Aug 9, 6:46 PM CDTTSTM WND DMG3 Nnw Brantford, NDBROKEN WINDOWS FROM VERY STRONG WINDS AND HAIL AT LEAST QUARTER SIZED. TIME ESTIMATED FROM RADAR.
Aug 9, 6:46 PM CDTTSTM WND DMG3 Wnw Brantford, NDBROKEN WINDOWS FROM VERY STORNG WINDS AND HAIL AT LEAST QUARTER SIZED. TIME ESTIMATED FROM RADAR.
Aug 9, 7:01 PM CDTHAIL 1.753 Ene Brantford, ND

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.

IssuedProductOfficeLasted
Aug 9, 4:01 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 11.1 hours before the alert went out and 170 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-pSkew-T log-p diagram, Bismarck Municip, ND at 12:00Z on 2021-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 851 joules per kilogram.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.
HodographHodograph, Bismarck Municip, ND at 12:00Z on 2021-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.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.
Mixed-layer CAPE
851 J/kg
Mixed-layer CIN
-361 J/kg
Mixed-layer LCL
1736 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

875 
WUUS53 KFGF 092303
SVRFGF
NDC005-027-100000-
/O.NEW.KFGF.SV.W.0080.210809T2303Z-210810T0000Z/

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

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Southeastern Benson County in northeastern North Dakota...
  Eddy County in northeastern North Dakota...

* Until 700 PM CDT.

* At 602 PM CDT, a severe thunderstorm was located near Bremen, or 38
  miles southwest of Devils Lake, moving northeast at 30 mph.

  HAZARD...Golf ball size hail and 70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           considerable tree damage. Wind damage is also likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  New Rockford, Sheyenne and Tokio.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

This thunderstorm is capable of producing all types of severe weather
including extremely large hail, destructive straight line winds and
tornadoes. Move quickly to a safe shelter such as an interior room, a
bathroom, closet or basement.

&&

LAT...LON 4800 9877 4797 9877 4795 9880 4759 9872
      4759 9926 4767 9927 4768 9930 4785 9930
      4785 9952
TIME...MOT...LOC 2302Z 246DEG 27KT 4771 9942 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

CJ
3 follow-up statements
713 
WWUS53 KFGF 092321
SVSFGF

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

NDC005-027-100000-
/O.CON.KFGF.SV.W.0080.000000T0000Z-210810T0000Z/
Benson ND-Eddy ND-
621 PM CDT Mon Aug 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM CDT
FOR SOUTHEASTERN BENSON AND EDDY COUNTIES...

At 621 PM CDT, a severe thunderstorm was located near Sheyenne, or 28
miles southwest of Devils Lake, moving northeast at 30 mph.

HAZARD...70 mph wind gusts and half dollar 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...
New Rockford, Sheyenne, Tokio, Brantford and Spirit Lake Nation. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This thunderstorm is capable of producing all types of severe weather
including extremely large hail, destructive straight line winds and
tornadoes. Move quickly to a safe shelter, such as an interior room,
a bathroom or closet or basement.

&&

LAT...LON 4800 9877 4797 9877 4795 9880 4759 9872
      4759 9926 4767 9927 4768 9930 4785 9930
TIME...MOT...LOC 2321Z 246DEG 27KT 4777 9922 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

CJ
985 
WWUS53 KFGF 092334
SVSFGF

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

NDC005-027-100000-
/O.CON.KFGF.SV.W.0080.000000T0000Z-210810T0000Z/
Benson ND-Eddy ND-
634 PM CDT Mon Aug 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM CDT
FOR SOUTHEASTERN BENSON AND EDDY COUNTIES...

At 634 PM CDT, a severe thunderstorm was located over Sheyenne, or 23
miles southwest of Devils Lake, moving northeast at 30 mph.

HAZARD...Two inch hail and 70 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect 
         considerable tree damage. Wind damage is also likely to 
         mobile homes, roofs, and outbuildings.

Locations impacted include...
New Rockford, Sheyenne, Tokio, Brantford and Spirit Lake Nation. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

This thunderstorm is capable of producing all types of severe weather
including extremely large hail, destructive straight line winds and
tornadoes. Move quickly to a safe shelter, such as an interior room,
a bathroom or closet or basement.

&&

LAT...LON 4800 9877 4797 9877 4795 9880 4759 9872
      4759 9926 4767 9927 4768 9930 4769 9930
      4787 9922
TIME...MOT...LOC 2334Z 246DEG 27KT 4781 9908 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...2.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

CJ
494 
WWUS53 KFGF 092350
SVSFGF

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

NDC005-027-100000-
/O.CON.KFGF.SV.W.0080.000000T0000Z-210810T0000Z/
Benson ND-Eddy ND-
650 PM CDT Mon Aug 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM CDT
FOR SOUTHEASTERN BENSON AND CENTRAL EDDY COUNTIES...

At 649 PM CDT, a severe thunderstorm was located over southwestern
Spirit Lake Nation, or 17 miles south of Devils Lake, moving
northeast at 30 mph.

THIS IS A DESTRUCTIVE STORM FOR SOUTHERN EDDY COUNTY.

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

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be severely injured. 
         Expect shattered windows, extensive damage to roofs, 
         siding, and vehicles.

Locations impacted include...
Tokio, Brantford and Spirit Lake Nation. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a dangerous storm. Prepare immediately for large destructive
hail capable of producing significant damage. People outside should
move to a shelter, inside a strong building and away from windows.

This thunderstorm is capable of producing all types of severe weather
including extremely large hail, destructive straight line winds and
tornadoes. Move quickly to a safe shelter, such as an interior room,
a bathroom or closet or basement.

&&

LAT...LON 4800 9877 4797 9877 4795 9880 4759 9872
      4759 9909 4790 9910
TIME...MOT...LOC 2349Z 246DEG 27KT 4786 9893 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...2.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

CJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 5:24 PM CDTSpecial Weather StatementFGFPierce36 min
Aug 9, 5:38 PM CDTSevere Thunderstorm Warning Considerable damage threatFGFBenson, Eddy52 min
Aug 9, 6:12 PM CDTSevere Thunderstorm WarningFGFBenson, Cavalier, Towner63 min
Aug 9, 6:56 PM CDTSpecial Weather StatementFGFTowner34 min
Aug 9, 6:59 PM CDTSevere Thunderstorm Warning Destructive damage threatFGFEddy31 min

Nearby

Severe Thunderstorm Warnings in North Dakota, 2021Every 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.