Alert archive / North Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 89, NWS Grand Forks, ND

August 9, 20214 counties in North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 9, 2021, 9:09 PM CDT for 4 counties in North Dakota. It was in force for 66 min. 10 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, 9:09 PM CDT (02:09 UTC)
Expired
Aug 9, 2021, 10:15 PM CDT
In force
66 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 Grand Forks County, ND, Griggs County, ND, Nelson County, ND, Steele County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 40 km from the middle of the area, began a volume at 02:13 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, 9:09 PM CDTFUNNEL CLOUD4 Wnw Sharon, NDA WELL DEVELOPED WALL CLOUD AND FUNNEL WERE VIEWED PASSING OVER A FARMSTEAD, AND REPORTED TO THE STEELE COUNTY SHERIFFS OFFICE.
Aug 9, 9:19 PM CDTTORNADO6 Nne Sharon, NDPOSSIBLE TORNADO INDICATED BY RADAR BASED DEBRIS SIGNATURE FROM 6NNE SHARON TO NEAT 8 NE SHARON BY 925 PM CDT.
Aug 9, 9:20 PM CDTTORNADO 25 Nne Sharon, NDA TORNADO TRACKED EASTWARD FOR ROUGHLY 3 MILES FROM FAR NORTHEAST SHARON TOWNSHIP ACROSS FAR NORTHWESTERN WESTFIELD TOWNSHIP TO AROUND 7 NE SHARON BY 928 PM CDT. A TORNADO DEBRIS SIGNATURE WAS EVIDENT ON KMVX RADAR. THE TORNADO COMPLETELY DISMANTLED AND DESTRO
Aug 9, 9:23 PM CDTTSTM WND DMG7 Ne Aneta, NDSPRUCE TREES PARTIALLY UPROOTED IN A SHELTERBELT. TIME ESTIMATED BASED ON RADAR.
Aug 9, 9:28 PM CDTFUNNEL CLOUD8 Ne Sharon, NDA WELL DEVELOPED WALL CLOUD WITH POSSIBLE FUNNEL WAS REPORTED BY A STORM CHASER/STORM SPOTTER.
Aug 9, 9:31 PM CDTTSTM WND GST 672 E Logan Center, NDPEAK WIND MEASURED AT AN NDAWN STATION AT 10 METERS.
Aug 9, 9:36 PM CDTTSTM WND DMG4 Ne Logan Center, ND12 INCH DIAMETER CORRONWOOD LIMB DOWN. PEAS SIZED HAIL ALSO REPORTED. RELAY VIA SOCIAL MEDIA. TIME ESTIMATED FROM RADAR.
Aug 9, 9:36 PM CDTTSTM WND DMG4 Ne Logan Center, ND12 INCH DIAMETER COTTONWOOD LIMB DOWN. PEA SIZED HAIL ALSO REPORTED. RELAYED VIA SOICAL MEDIA. TIME ESTIMATED FROM RADAR.
Aug 9, 9:42 PM CDTTORNADO 15 Wnw Northwood, NDA FEW COTTONWOOD TREES WERE SNAPPED OR UPROOTED IN A SHELTERBELT BETWEEN ABOUT 942 AND 943 PM CDT. LIKELY A BRIEF TORNADO TOUCHDOWN BASED ON RADAR SIGNATURE. PEAK WINDS ESTIMATED TO 90 MPH. MAXIMUM WIDTH TO 150 YARDS. TIME ESTIMATED BASED ON RADAR.
Aug 9, 9:45 PM CDTTSTM WND DMG2 Wsw Northwood, NDA POPLAR TREE WAS BLOWN DOWN ALONG WITH SEVERAL LARGE TREE BRANCHES AND LIMBS AT THE NORTHWOOD GOLF COURSE. LIKELY CAUSED BY REAR FLANK DOWNDRAFT FROM A SUPERCELL THUNDERSTORM. 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.

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

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 00:00Z, 2.2 hours before the alert went out and 249 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 00:00Z on 2021-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 296 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 00:00Z on 2021-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -40 square meters per square second.1939587897Sfc1 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
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.

627 
WUUS53 KFGF 100209
SVRFGF
NDC035-039-063-091-100315-
/O.NEW.KFGF.SV.W.0089.210810T0209Z-210810T0315Z/

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

The National Weather Service in Grand Forks has issued a

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

* Until 1015 PM CDT.

* At 908 PM CDT, a severe thunderstorm was located over Aneta, or 46
  miles west of Grand Forks, moving east at 25 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...
  Aneta around 910 PM CDT.

Other locations in the path of this severe thunderstorm include Logan
Center, Kempton and Northwood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4799 9765 4767 9740 4767 9747 4766 9748
      4756 9823 4774 9825
TIME...MOT...LOC 0208Z 253DEG 24KT 4771 9802 

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

$$

TG
1 follow-up statement
732 
WWUS53 KFGF 100238
SVSFGF

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

NDC039-100248-
/O.CAN.KFGF.SV.W.0089.000000T0000Z-210810T0315Z/
Griggs ND-
938 PM CDT Mon Aug 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN GRIGGS COUNTY IS
CANCELLED...
    
The severe 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 1100 PM CDT for
southeastern and northeastern North Dakota.

LAT...LON 4799 9765 4767 9740 4767 9747 4766 9748
      4759 9797 4781 9793
TIME...MOT...LOC 0238Z 253DEG 24KT 4777 9774 

$$

NDC035-063-091-100315-
/O.CON.KFGF.SV.W.0089.000000T0000Z-210810T0315Z/
Grand Forks ND-Nelson ND-Steele ND-
938 PM CDT Mon Aug 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT
FOR SOUTHWESTERN GRAND FORKS...SOUTHEASTERN NELSON AND NORTHERN
STEELE COUNTIES...

At 938 PM CDT, a severe thunderstorm was located near Logan Center,
or 32 miles west of Grand Forks, moving east 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...
  Kempton and Northwood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4799 9765 4767 9740 4767 9747 4766 9748
      4759 9797 4781 9793
TIME...MOT...LOC 0238Z 253DEG 24KT 4777 9774 

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

$$

TG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 7:04 PM CDTSevere Thunderstorm WarningFGFCavalier, Ramsey, Towner56 min
Aug 9, 7:11 PM CDTTornado WarningFGFCavalier, Ramsey, Towner34 min
Aug 9, 7:29 PM CDTSevere Thunderstorm Warning Considerable damage threatFGFEddy, Griggs, Nelson46 min
Aug 9, 7:57 PM CDTSevere Thunderstorm WarningFGFCavalier, Pembina, Ramsey, Walsh63 min
Aug 9, 8:08 PM CDTSevere Thunderstorm WarningFGFGrand Forks, Nelson27 min
Aug 9, 8:12 PM CDTSevere Thunderstorm Warning Considerable damage threatFGFEddy, Griggs, Nelson63 min
Aug 9, 8:28 PM CDTTornado WarningFGFGriggs, Nelson32 min
Aug 9, 8:52 PM CDTSevere Thunderstorm WarningFGFCavalier, Pembina38 min
Aug 9, 9:20 PM CDTTornado WarningFGFGrand Forks, Nelson, Steele40 min
Aug 9, 9:42 PM CDTTornado WarningFGFGrand Forks48 min
Aug 9, 9:54 PM CDTSevere Thunderstorm Warning Considerable damage threatFGFGrand Forks, Steele66 min
Aug 9, 10:08 PM CDTSpecial Weather StatementFGFPembina52 min
Aug 9, 10:30 PM CDTSevere Thunderstorm Warning Considerable damage threatFGFGrand Forks, Steele, Traill30 min
Aug 9, 10:42 PM CDTSevere Thunderstorm Warning Considerable damage threatFGFGrand Forks, Traill63 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.