Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 121, NWS Grand Forks, ND

October 8, 20214 counties in Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Oct 8, 2021, 6:21 PM CDT for 4 counties in Minnesota. It was in force for 32 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, 6:21 PM CDT (23:21 UTC)
Expired
Oct 8, 2021, 6:53 PM CDT
In force
32 min
Issued by
NWS Grand Forks, ND
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Beltrami County, MN, Lake of the Woods County, MN, Marshall County, MN, Roseau County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 174 km from the middle of the area, began a volume at 23:22 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

International Fa, MN (KINL), launched 12:00Z, 11.4 hours before the alert went out and 167 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, International Fa, MN at 12:00Z on 2021-10-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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, International Fa, MN at 12:00Z on 2021-10-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.1939Sfc1 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
17 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
889 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

407 
WUUS53 KFGF 082321
SVRFGF
MNC007-077-089-135-090015-
/O.NEW.KFGF.SV.W.0121.211008T2321Z-211009T0015Z/

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

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Northeastern Marshall County in northwestern Minnesota...
  Southeastern Roseau County in northwestern Minnesota...
  Northwestern Beltrami County in north central Minnesota...
  Southwestern Lake of the Woods County in north central Minnesota...

* Until 715 PM CDT.

* At 621 PM CDT, a severe thunderstorm was located over Casperson, or
  20 miles south of Roseau, moving east 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...
  Skime around 635 PM CDT.

Other locations in the path of this severe thunderstorm include Hayes
Lake State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4849 9578 4860 9586 4880 9531 4849 9515
TIME...MOT...LOC 2321Z 255DEG 14KT 4855 9570 

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

$$

Perroux
1 follow-up statement
438 
WWUS53 KFGF 082353
SVSFGF

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

MNC007-077-089-135-090003-
/O.CAN.KFGF.SV.W.0121.000000T0000Z-211009T0015Z/
Marshall MN-Roseau MN-Beltrami MN-Lake of the Woods MN-
653 PM CDT Fri Oct 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MARSHALL...
SOUTHEASTERN ROSEAU...NORTHWESTERN BELTRAMI AND SOUTHWESTERN LAKE OF
THE WOODS 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.

LAT...LON 4849 9578 4860 9586 4880 9531 4849 9515
TIME...MOT...LOC 2351Z 255DEG 14KT 4858 9552 

$$

Perroux

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 8, 5:12 PM CDTSpecial Weather StatementFGFPolk33 min
Oct 8, 5:16 PM CDTSevere Thunderstorm WarningFGFPennington, Polk, Red Lake59 min
Oct 8, 5:26 PM CDTSevere Thunderstorm WarningFGFNorman, Polk52 min
Oct 8, 5:31 PM CDTSpecial Weather StatementFGFMarshall29 min
Oct 8, 5:41 PM CDTSpecial Weather StatementFGFRoseau34 min
Oct 8, 6:04 PM CDTSevere Thunderstorm WarningFGFPennington, Polk, Red Lake56 min
Oct 8, 6:06 PM CDTSpecial Weather StatementFGFNorman24 min
Oct 8, 6:17 PM CDTSpecial Weather StatementFGFPolk28 min
Oct 8, 6:30 PM CDTSevere Thunderstorm WarningFGFClay, Norman37 min
Oct 8, 6:49 PM CDTSpecial Weather StatementFGFRed Lake26 min
Oct 8, 6:59 PM CDTSpecial Weather StatementFGFNorman31 min

Nearby

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