Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 120, NWS Grand Forks, ND

October 8, 2021Pennington County, Polk County, Red Lake County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Oct 8, 2021, 6:04 PM CDT for Pennington County, Polk County, Red Lake County, Minnesota. It was in force for 56 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, 6:04 PM CDT (23:04 UTC)
Expired
Oct 8, 2021, 7:00 PM CDT
In force
56 min
Issued by
NWS Grand Forks, ND
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Pennington County, MN, Polk County, MN, Red Lake County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 86 km from the middle of the area, began a volume at 23:05 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, 11.1 hours before the alert went out and 235 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°0°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.

522 
WUUS53 KFGF 082304
SVRFGF
MNC113-119-125-090000-
/O.NEW.KFGF.SV.W.0120.211008T2304Z-211009T0000Z/

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

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Western Red Lake County in northwestern Minnesota...
  Central Polk County in northwestern Minnesota...
  Southwestern Pennington County in northwestern Minnesota...

* Until 700 PM CDT.

* At 603 PM CDT, a severe thunderstorm was located over Huot, or 20
  miles southwest of Thief River Falls, moving northeast at 10 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...
  Perault around 620 PM CDT.

Other locations in the path of this severe thunderstorm include
Wylie, Red Lake Falls, Terrebonne and St. Hilaire.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4778 9601 4776 9630 4776 9635 4775 9642
      4786 9651 4807 9626
TIME...MOT...LOC 2303Z 240DEG 11KT 4786 9640 

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

$$

Perroux
2 follow-up statements
961 
WWUS53 KFGF 082345
SVSFGF

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

MNC113-119-082354-
/O.CAN.KFGF.SV.W.0120.000000T0000Z-211009T0000Z/
Polk MN-Pennington MN-
645 PM CDT Fri Oct 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL POLK AND SOUTHWESTERN
PENNINGTON COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4778 9601 4776 9627 4776 9633 4781 9636
      4785 9635 4785 9637 4787 9638 4796 9622
      4796 9617
TIME...MOT...LOC 2344Z 240DEG 11KT 4792 9624 

$$

MNC125-090000-
/O.CON.KFGF.SV.W.0120.000000T0000Z-211009T0000Z/
Red Lake MN-
645 PM CDT Fri Oct 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM CDT
FOR WESTERN RED LAKE COUNTY...

At 644 PM CDT, a severe thunderstorm was located near Red Lake Falls,
or 13 miles south of Thief River Falls, 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.

Locations impacted include...
  Terrebonne.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4778 9601 4776 9627 4776 9633 4781 9636
      4785 9635 4785 9637 4787 9638 4796 9622
      4796 9617
TIME...MOT...LOC 2344Z 240DEG 11KT 4792 9624 

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

$$

Perroux
842 
WWUS53 KFGF 082351
SVSFGF

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

MNC125-090001-
/O.EXP.KFGF.SV.W.0120.000000T0000Z-211009T0000Z/
Red Lake MN-
651 PM CDT Fri Oct 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN RED LAKE COUNTY WILL
EXPIRE AT 700 PM CDT...
                
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 will be allowed to expire.  However small hail
is still possible with this thunderstorm.

LAT...LON 4778 9601 4776 9627 4776 9633 4781 9636
      4785 9635 4785 9637 4787 9638 4796 9622
      4796 9617
TIME...MOT...LOC 2351Z 240DEG 11KT 4793 9622 

$$

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, 6:06 PM CDTSpecial Weather StatementFGFNorman24 min
Oct 8, 6:17 PM CDTSpecial Weather StatementFGFPolk28 min
Oct 8, 6:21 PM CDTSevere Thunderstorm WarningFGFBeltrami, Lake of the Woods, Marshall, Roseau32 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.