Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 95, NWS Grand Forks, ND

August 20, 20215 counties in Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 20, 2021, 1:53 PM CDT for 5 counties in Minnesota. It was in force for 67 min. 1 report 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 20, 2021, 1:53 PM CDT (18:53 UTC)
Expired
Aug 20, 2021, 3:00 PM CDT
In force
67 min
Issued by
NWS Grand Forks, ND
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Beltrami County, MN, Clearwater County, MN, Lake of the Woods County, MN, Marshall County, MN, Pennington County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 161 km from the middle of the area, began a volume at 18:57 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 20, 1:55 PM CDTTSTM WND DMG5 Ese High Landing, MNTIN ROOF PANEL BLOWN OFF A SHED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 6.9 hours before the alert went out and 161 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 2021-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 347 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 2021-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.193958Sfc1 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
347 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
1086 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

286 
WUUS53 KFGF 201853
SVRFGF
MNC007-029-077-089-113-202000-
/O.NEW.KFGF.SV.W.0095.210820T1853Z-210820T2000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Forks ND
153 PM CDT Fri Aug 20 2021

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Southeastern Marshall County in northwestern Minnesota...
  Northern Beltrami County in north central Minnesota...
  Eastern Pennington County in northwestern Minnesota...
  Southwestern Lake of the Woods County in north central Minnesota...
  Northwestern Clearwater County in northwestern Minnesota...

* Until 300 PM CDT.

* At 153 PM CDT, a severe thunderstorm was located 7 miles east of
  Roland, or 27 miles east of Thief River Falls, moving northeast at
  45 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Northwestern Red Lake Nation around 200 PM CDT.

Other locations in the path of this severe thunderstorm include
Jelle, Thorhult, Fourtown and Oaks Corner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm. 
Move indoors immediately. Lightning is one of nature's leading 
killers. Remember, if you can hear thunder, you are close enough to 
be struck by lightning.

If on or near Upper and Lower Red Lakes, get away from the water and 
move indoors or inside a vehicle. Remember, lightning can strike out 
to 15 miles from the parent thunderstorm. If you can hear thunder, 
you are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4784 9558 4793 9558 4794 9571 4796 9571
      4797 9583 4814 9589 4854 9540 4854 9534
      4859 9534 4871 9519 4847 9460 4803 9452
TIME...MOT...LOC 1853Z 227DEG 37KT 4799 9562 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CJ
2 follow-up statements
333 
WWUS53 KFGF 201926
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
226 PM CDT Fri Aug 20 2021

MNC089-113-201935-
/O.CAN.KFGF.SV.W.0095.000000T0000Z-210820T2000Z/
Marshall MN-Pennington MN-
226 PM CDT Fri Aug 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MARSHALL AND
EASTERN PENNINGTON COUNTIES 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 1000 PM CDT for
north central and northwestern Minnesota.

LAT...LON 4791 9516 4802 9545 4838 9559 4854 9540
      4854 9534 4859 9534 4871 9519 4847 9460
      4803 9452
TIME...MOT...LOC 1925Z 227DEG 37KT 4822 9525 

$$

MNC007-029-077-202000-
/O.CON.KFGF.SV.W.0095.000000T0000Z-210820T2000Z/
Beltrami MN-Lake of the Woods MN-Clearwater MN-
226 PM CDT Fri Aug 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR NORTHERN BELTRAMI...SOUTHWESTERN LAKE OF THE WOODS AND NORTH
CENTRAL CLEARWATER COUNTIES...

At 225 PM CDT, a severe thunderstorm was located over Thorhult, or 42
miles east of Thief River Falls, moving northeast at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  Oaks Corner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near Upper and Lower Red Lakes, get away from the water and 
move indoors or inside a vehicle. Remember, lightning can strike out 
to 15 miles from the parent thunderstorm. If you can hear thunder, 
you are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4791 9516 4802 9545 4838 9559 4854 9540
      4854 9534 4859 9534 4871 9519 4847 9460
      4803 9452
TIME...MOT...LOC 1925Z 227DEG 37KT 4822 9525 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CJ
932 
WWUS53 KFGF 201954
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
254 PM CDT Fri Aug 20 2021

MNC007-029-077-202003-
/O.EXP.KFGF.SV.W.0095.000000T0000Z-210820T2000Z/
Beltrami MN-Lake of the Woods MN-Clearwater MN-
254 PM CDT Fri Aug 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN BELTRAMI...
SOUTHWESTERN LAKE OF THE WOODS AND NORTH CENTRAL CLEARWATER COUNTIES
WILL EXPIRE AT 300 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 gusty
winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
north central and northwestern Minnesota.

LAT...LON 4791 9516 4802 9545 4838 9559 4854 9540
      4854 9534 4859 9534 4871 9519 4847 9460
      4803 9452
TIME...MOT...LOC 1953Z 227DEG 37KT 4840 9495 

$$

CJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 9:47 AM CDTSpecial Weather StatementFGFMarshall, Pennington, Polk, Red Lake28 min
Aug 20, 11:04 AM CDTAreal Flood AdvisoryFGFPolk4 hr
Aug 20, 12:28 PM CDTSpecial Weather StatementFGFNorman, Polk32 min
Aug 20, 1:02 PM CDTSpecial Weather StatementFGFPennington, Red Lake28 min
Aug 20, 1:09 PM CDTSevere Thunderstorm WarningFGFPennington, Polk, Red Lake51 min
Aug 20, 2:00 PM CDTSpecial Weather StatementFGFRoseau60 min
Aug 20, 2:52 PM CDTSpecial Weather StatementFGFLake of the Woods53 min
Aug 20, 3:31 PM CDTSpecial Weather StatementFGFGrant59 min
Aug 20, 4:12 PM CDTSpecial Weather StatementFGFWadena33 min
Aug 20, 4:19 PM CDTSpecial Weather StatementFGFBeltrami26 min
Aug 20, 4:20 PM CDTSpecial Weather StatementFGFBeltrami25 min
Aug 20, 4:22 PM CDTSpecial Weather StatementFGFClay53 min
Aug 20, 4:43 PM CDTSpecial Weather StatementFGFBeltrami32 min
Aug 20, 4:49 PM CDTSevere Thunderstorm WarningFGFNorman, Polk26 min
Aug 20, 5:07 PM CDTSevere Thunderstorm WarningFGFOtter Tail, Wadena38 min
Aug 20, 5:13 PM CDTSevere Thunderstorm Warning Considerable damage threatFGFPennington, Polk, Red Lake39 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.