Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 122, NWS Grand Forks, ND

October 8, 2021Clay County, Norman County, Minnesota; Cass County, Traill County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Oct 8, 2021, 6:30 PM CDT for Clay County, Norman County, Minnesota; Cass County, Traill County, North Dakota. It was in force for 37 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Oct 8, 2021, 6:30 PM CDT (23:30 UTC)
Expired: Oct 8, 2021, 7:07 PM CDT
In force: 37 min
Issued by: NWS Grand Forks, ND
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Clay County, MN, Norman County, MN, Cass County, ND, Traill County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 58 km from the middle of the area, began a volume at 23:33 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.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 11.5 hours before the alert went out and 272 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: 430 J/kg
Mixed-layer CIN: -264 J/kg
Mixed-layer LCL: 1157 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 57 m²/s²
0-3 km storm-relative helicity: 120 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

999 
WUUS53 KFGF 082330
SVRFGF
MNC027-107-NDC017-097-090030-
/O.NEW.KFGF.SV.W.0122.211008T2330Z-211009T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Forks ND
630 PM CDT Fri Oct 8 2021

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Northwestern Clay County in northwestern Minnesota...
  Southwestern Norman County in northwestern Minnesota...
  Northeastern Cass County in southeastern North Dakota...
  Southeastern Traill County in southeastern North Dakota...

* Until 730 PM CDT.

* At 629 PM CDT, a severe thunderstorm was located over Argusville,
  or 15 miles northwest of Fargo, moving northeast at 15 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Gardner around 640 PM CDT.

Other locations in the path of this severe thunderstorm include
Georgetown and Perley.

This includes Interstate 29 between mile markers 76 and 88.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4700 9696 4706 9709 4733 9688 4715 9651
TIME...MOT...LOC 2329Z 239DEG 11KT 4707 9695 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Perroux

1 follow-up statement

470 
WWUS53 KFGF 090007
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
707 PM CDT Fri Oct 8 2021

MNC027-107-NDC017-097-090017-
/O.CAN.KFGF.SV.W.0122.000000T0000Z-211009T0030Z/
Clay MN-Norman MN-Cass ND-Traill ND-
707 PM CDT Fri Oct 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CLAY...
SOUTHWESTERN NORMAN...NORTHEASTERN CASS AND SOUTHEASTERN TRAILL
COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However small hail is
still possible with this thunderstorm.

LAT...LON 4700 9696 4706 9709 4733 9688 4715 9651
TIME...MOT...LOC 0004Z 239DEG 11KT 4713 9680 

$$

Perroux

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 8, 5:12 PM CDT	Special Weather Statement	FGF	Polk	33 min
Oct 8, 5:16 PM CDT	Severe Thunderstorm Warning	FGF	Pennington, Polk, Red Lake	59 min
Oct 8, 5:26 PM CDT	Severe Thunderstorm Warning	FGF	Norman, Polk	52 min
Oct 8, 5:31 PM CDT	Special Weather Statement	FGF	Marshall	29 min
Oct 8, 5:41 PM CDT	Special Weather Statement	FGF	Roseau	34 min
Oct 8, 6:04 PM CDT	Severe Thunderstorm Warning	FGF	Pennington, Polk, Red Lake	56 min
Oct 8, 6:06 PM CDT	Special Weather Statement	FGF	Norman	24 min
Oct 8, 6:17 PM CDT	Special Weather Statement	FGF	Polk	28 min
Oct 8, 6:21 PM CDT	Severe Thunderstorm Warning	FGF	Beltrami, Lake of the Woods, Marshall, Roseau	32 min
Oct 8, 6:49 PM CDT	Special Weather Statement	FGF	Red Lake	26 min
Oct 8, 6:59 PM CDT	Special Weather Statement	FGF	Norman	31 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2021 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.