Alert archive / North Dakota / Tornado Warnings in 2021

Tornado Warning 9, NWS Grand Forks, ND

August 20, 2021Barnes County, Griggs County, Steele County, North Dakota

NWS Grand Forks, ND issued this tornado warning at Aug 20, 2021, 4:11 PM CDT for Barnes County, Griggs County, Steele County, North Dakota. It was in force for 49 min. 1 report 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 20, 2021, 4:11 PM CDT (21:11 UTC)
Expired: Aug 20, 2021, 5:00 PM CDT
In force: 49 min
Issued by: NWS Grand Forks, ND
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Barnes County, ND, Griggs County, ND, Steele County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 56 km from the middle of the area, began a volume at 21:11 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 20, 4:32 PM CDT	FUNNEL CLOUD	6 Nnw Luverne, ND	PERSISTENT WALL CLOUD WITH BRIEF FUNNEL.

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 20, 2:24 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 9.2 hours before the alert went out and 214 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: 306 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 609 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 163 m²/s²
0-3 km storm-relative helicity: 141 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

576 
WFUS53 KFGF 202111
TORFGF
NDC003-039-091-202200-
/O.NEW.KFGF.TO.W.0009.210820T2111Z-210820T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Grand Forks ND
411 PM CDT Fri Aug 20 2021

The National Weather Service in Grand Forks has issued a

* Tornado Warning for...
  Southeastern Griggs County in southeastern North Dakota...
  North central Barnes County in southeastern North Dakota...
  Southwestern Steele County in southeastern North Dakota...

* Until 500 PM CDT.
    
* At 411 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Sibley, or 19 miles north of Valley City, moving
  northeast at 25 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Sibley around 420 PM CDT.
  Luverne around 430 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Blabon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4714 9805 4719 9818 4752 9817 4748 9782
      4738 9769
TIME...MOT...LOC 2111Z 211DEG 20KT 4720 9807 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

CJ

2 follow-up statements

211 
WWUS53 KFGF 202127
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
427 PM CDT Fri Aug 20 2021

NDC003-202137-
/O.CAN.KFGF.TO.W.0009.000000T0000Z-210820T2200Z/
Barnes ND-
427 PM CDT Fri Aug 20 2021

...THE TORNADO WARNING FOR NORTH CENTRAL BARNES COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
southeastern North Dakota.

LAT...LON 4725 9813 4752 9817 4748 9782 4738 9769
      4724 9793
TIME...MOT...LOC 2127Z 211DEG 20KT 4728 9800 

$$

NDC039-091-202200-
/O.CON.KFGF.TO.W.0009.000000T0000Z-210820T2200Z/
Griggs ND-Steele ND-
427 PM CDT Fri Aug 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM CDT FOR
SOUTHEASTERN GRIGGS AND SOUTHWESTERN STEELE COUNTIES...
    
At 427 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Luverne, or 24 miles north of Valley City, moving
northeast at 25 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
  Blabon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4725 9813 4752 9817 4748 9782 4738 9769
      4724 9793
TIME...MOT...LOC 2127Z 211DEG 20KT 4728 9800 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

CJ

329 
WWUS53 KFGF 202151
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
451 PM CDT Fri Aug 20 2021

NDC039-091-202201-
/O.EXP.KFGF.TO.W.0009.000000T0000Z-210820T2200Z/
Griggs ND-Steele ND-
451 PM CDT Fri Aug 20 2021

...THE TORNADO WARNING FOR SOUTHEASTERN GRIGGS AND SOUTHWESTERN
STEELE COUNTIES WILL EXPIRE AT 500 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
southeastern North Dakota.

LAT...LON 4725 9813 4752 9817 4748 9782 4738 9769
      4724 9793
TIME...MOT...LOC 2151Z 211DEG 20KT 4739 9790 

$$

CJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 9:47 AM CDT	Special Weather Statement	FGF	Grand Forks	28 min
Aug 20, 11:04 AM CDT	Areal Flood Advisory	FGF	Grand Forks	4 hr
Aug 20, 11:12 AM CDT	Special Weather Statement	FGF	Cass	33 min
Aug 20, 2:43 PM CDT	Tornado Warning	FGF	Barnes, Cass	47 min
Aug 20, 3:24 PM CDT	Special Weather Statement	FGF	Cass	36 min
Aug 20, 3:49 PM CDT	Special Weather Statement	FGF	Griggs	56 min
Aug 20, 4:00 PM CDT	Special Weather Statement	FGF	Traill	60 min
Aug 20, 4:13 PM CDT	Tornado Warning	FGF	Cass, Traill	47 min
Aug 20, 4:49 PM CDT	Severe Thunderstorm Warning	FGF	Traill	26 min
Aug 20, 4:51 PM CDT	Special Weather Statement	FGF	Steele	54 min
Aug 20, 5:11 PM CDT	Special Weather Statement	FGF	Ramsey	49 min
Aug 20, 5:13 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FGF	Grand Forks, Traill	39 min
Aug 20, 6:24 PM CDT	Special Weather Statement	FGF	Walsh	51 min

Nearby

Tornado Warnings in North Dakota, 2021 Every tornado warning in 2021 Tornadoes 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.