Alert archive / North Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 91, NWS Grand Forks, ND

August 9, 2021Grand Forks County, Steele County, Traill County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 9, 2021, 10:30 PM CDT for Grand Forks County, Steele County, Traill County, North Dakota. It was in force for 30 min. 2 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, 10:30 PM CDT (03:30 UTC)
Expired: Aug 9, 2021, 11:00 PM CDT
In force: 30 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 Grand Forks County, ND, Steele County, ND, Traill County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 11 km from the middle of the area, began a volume at 03:31 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, 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.

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, 3.5 hours before the alert went out and 279 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.

194 
WUUS53 KFGF 100330
SVRFGF
NDC035-091-097-100400-
/O.NEW.KFGF.SV.W.0091.210810T0330Z-210810T0400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Forks ND
1030 PM CDT Mon Aug 9 2021

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Southeastern Grand Forks County in northeastern North Dakota...
  Northern Traill County in southeastern North Dakota...
  Northeastern Steele County in southeastern North Dakota...

* Until 1100 PM CDT.

* At 1029 PM CDT, severe thunderstorms were located along a line
  extending from near Holmes to Roseville, 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.

* Severe thunderstorms will be near...
  Reynolds and Buxton around 1045 PM CDT.

Other locations in the path of these severe thunderstorms include
Hillsboro and Cummings.

This includes Interstate 29 between mile markers 103 and 125.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4768 9749 4772 9693 4771 9692 4737 9694
      4741 9753
TIME...MOT...LOC 0329Z 271DEG 26KT 4767 9727 4745 9738 

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, 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, 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, 10:42 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.