Alert archive / North Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 84, NWS Grand Forks, ND

August 9, 2021Eddy County, Griggs County, Nelson County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 9, 2021, 7:29 PM CDT for Eddy County, Griggs County, Nelson County, North Dakota. It was in force for 46 min. 4 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, 7:29 PM CDT (00:29 UTC)
Expired: Aug 9, 2021, 8:15 PM CDT
In force: 46 min
Issued by: NWS Grand Forks, ND
Area: Storm-based polygon
Tornado: Possible
Damage threat: Considerable
Hail: 1.75 in
Wind: 70.0 mph

Counties Eddy County, ND, Griggs County, ND, Nelson County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 83 km from the middle of the area, began a volume at 00:31 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, 7:30 PM CDT	HAIL 1.25	6 S Hamar, ND	VERY HEAVY RAINS ANDA FEW QUARTER TO HALF DOLLAR SIZED HAIL.
Aug 9, 8:00 PM CDT	HAIL 1.25	2 E Pekin, ND	HAIL FROM SOUTH OF TOLNA THROUGH EAST OF PEKIN, RANGING FROM NICKLE TO HALF DOLLAR SIZED.
Aug 9, 8:10 PM CDT	HAIL 1.5	4 Nne Mchenry, ND	VERY HEAVY RAIN AND A FEW LARGE HAIL.
Aug 9, 8:24 PM CDT	TSTM WND DMG	4 N Mcville, ND	SEVERAL LARGE 4-6 INCH TREE BRANCHES BROKEN DOWN AROUND A FARMSTEAD.

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

Bismarck Municip, ND (KBIS), launched 00:00Z, 0.5 hours before the alert went out and 204 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: 296 J/kg
Mixed-layer CIN: -462 J/kg
Mixed-layer LCL: 1238 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: -40 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

193 
WUUS53 KFGF 100029
SVRFGF
NDC027-039-063-100115-
/O.NEW.KFGF.SV.W.0084.210810T0029Z-210810T0115Z/

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

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Southern Nelson County in northeastern North Dakota...
  Northern Griggs County in southeastern North Dakota...
  Eastern Eddy County in northeastern North Dakota...

* Until 815 PM CDT.

* At 729 PM CDT, a severe thunderstorm was located near Tolna, or 30
  miles southeast of Devils Lake, moving northeast at 35 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.

* This severe thunderstorm will be near...
  Pekin around 740 PM CDT.

Other locations in the path of this severe thunderstorm include
McVille.

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, closet or basement.

&&

LAT...LON 4785 9858 4785 9853 4786 9852 4799 9799
      4767 9788 4767 9798 4763 9799 4761 9804
      4752 9850 4759 9850 4759 9903 4773 9906
TIME...MOT...LOC 0029Z 245DEG 30KT 4777 9847 

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

$$

CJ

1 follow-up statement

469 
WWUS53 KFGF 100055
SVSFGF

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

NDC027-039-063-100115-
/O.CON.KFGF.SV.W.0084.000000T0000Z-210810T0115Z/
Nelson ND-Griggs ND-Eddy ND-
755 PM CDT Mon Aug 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR SOUTHERN NELSON...NORTHWESTERN GRIGGS AND SOUTHEASTERN EDDY
COUNTIES...

At 754 PM CDT, a severe thunderstorm was located near McVille, or 36
miles southeast of Devils Lake, moving northeast at 35 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of
southern Nelson, northwestern Griggs and southeastern Eddy Counties.

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 4785 9853 4786 9852 4799 9799 4778 9792
      4755 9850 4759 9850 4759 9898 4772 9886
TIME...MOT...LOC 0054Z 245DEG 30KT 4786 9818 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CJ

The office that day

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

Issued	Product	Office	Counties	Lasted
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, 7:57 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, 9:54 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Grand Forks, Steele	66 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
Aug 9, 10:42 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Grand Forks, Traill	63 min

Nearby

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.