Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 119, NWS Grand Forks, ND

October 8, 2021Norman County, Polk County, Minnesota; Traill County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Oct 8, 2021, 5:26 PM CDT for Norman County, Polk County, Minnesota; Traill County, North Dakota. It was in force for 52 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, 5:26 PM CDT (22:26 UTC)
Expired
Oct 8, 2021, 6:18 PM CDT
In force
52 min
Issued by
NWS Grand Forks, ND
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Norman County, MN, Polk County, MN, Traill County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 33 km from the middle of the area, began a volume at 22:28 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, 10.4 hours before the alert went out and 292 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.

329 
WUUS53 KFGF 082226
SVRFGF
MNC107-119-NDC097-082330-
/O.NEW.KFGF.SV.W.0119.211008T2226Z-211008T2330Z/

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

The National Weather Service in Grand Forks has issued a

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

* Until 630 PM CDT.

* At 526 PM CDT, a severe thunderstorm was located near Caledonia, or
  31 miles south of Grand Forks, 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...
  Caledonia around 545 PM CDT.

Other locations in the path of this severe thunderstorm include
Shelly, Nielsville, Climax and Eldred.

This includes Interstate 29 between mile markers 108 and 109.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4738 9698 4746 9709 4772 9683 4752 9654
TIME...MOT...LOC 2226Z 228DEG 10KT 4745 9698 

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

$$

Perroux
2 follow-up statements
400 
WWUS53 KFGF 082247
SVSFGF

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

MNC107-119-NDC097-082330-
/O.CON.KFGF.SV.W.0119.000000T0000Z-211008T2330Z/
Norman MN-Polk MN-Traill ND-
547 PM CDT Fri Oct 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CDT
FOR NORTHWESTERN NORMAN...SOUTHWESTERN POLK AND NORTHEASTERN TRAILL
COUNTIES...

At 547 PM CDT, a severe thunderstorm was located over Caledonia, or
29 miles south of Grand Forks, 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.

Locations impacted include...
  Shelly, Nielsville, Climax and Eldred.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4741 9695 4748 9707 4772 9683 4752 9654
TIME...MOT...LOC 2247Z 228DEG 10KT 4749 9691 

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

$$

Perroux
745 
WWUS53 KFGF 082318
SVSFGF

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

MNC107-119-NDC097-082327-
/O.CAN.KFGF.SV.W.0119.000000T0000Z-211008T2330Z/
Norman MN-Polk MN-Traill ND-
618 PM CDT Fri Oct 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN NORMAN...
SOUTHWESTERN POLK AND NORTHEASTERN 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 4741 9695 4748 9707 4772 9683 4752 9654
TIME...MOT...LOC 2316Z 228DEG 10KT 4755 9682 

$$

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, 5:31 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, 6:21 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, 2021Severe 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.