Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 117, NWS Grand Forks, ND

September 16, 20215 counties in Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Sep 16, 2021, 1:59 AM CDT for 5 counties in Minnesota. It was in force for 49 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
Sep 16, 2021, 1:59 AM CDT (06:59 UTC)
Expired
Sep 16, 2021, 2:48 AM CDT
In force
49 min
Issued by
NWS Grand Forks, ND
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Beltrami County, MN, Clearwater County, MN, Hubbard County, MN, Mahnomen County, MN, Polk County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 137 km from the middle of the area, began a volume at 06:59 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 00:00Z, 7.0 hours before the alert went out and 201 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 00:00Z on 2021-09-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 00:00Z on 2021-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 110 square meters per square second.19395878Sfc1 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
6 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
1751 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
110 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

568 
WUUS53 KFGF 160659
SVRFGF
MNC007-029-057-087-119-160800-
/O.NEW.KFGF.SV.W.0117.210916T0659Z-210916T0800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Forks ND
159 AM CDT Thu Sep 16 2021

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Northwestern Hubbard County in north central Minnesota...
  Southeastern Polk County in northwestern Minnesota...
  South central Beltrami County in north central Minnesota...
  Northeastern Mahnomen County in northwestern Minnesota...
  Central Clearwater County in northwestern Minnesota...

* Until 300 AM CDT.

* At 158 AM CDT, a severe thunderstorm was located near Fosston, or
  37 miles west of Bemidji, moving east at 40 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...
  Lengby and Weme around 205 AM CDT.
  Ebro around 210 AM CDT.

Other locations in the path of this severe thunderstorm include
Bagley, Shevlin, Pinewood and Alida.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4747 9588 4761 9580 4769 9557 4760 9480
      4731 9507
TIME...MOT...LOC 0658Z 286DEG 33KT 4759 9566 

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

$$

Lynch
1 follow-up statement
050 
WWUS53 KFGF 160748
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
248 AM CDT Thu Sep 16 2021

MNC007-029-057-087-119-160757-
/O.CAN.KFGF.SV.W.0117.000000T0000Z-210916T0800Z/
Hubbard MN-Polk MN-Beltrami MN-Mahnomen MN-Clearwater MN-
248 AM CDT Thu Sep 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN HUBBARD...
SOUTHEASTERN POLK...SOUTH CENTRAL BELTRAMI...NORTHEASTERN MAHNOMEN
AND CENTRAL CLEARWATER 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 and
gusty winds are still possible with this thunderstorm.

LAT...LON 4747 9588 4761 9580 4769 9557 4760 9480
      4731 9507
TIME...MOT...LOC 0745Z 286DEG 33KT 4746 9501 

$$

Lynch

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 15, 10:38 PM CDTSevere Thunderstorm WarningFGFKittson, Marshall52 min
Sep 15, 10:47 PM CDTSevere Thunderstorm WarningFGFMarshall, Polk43 min
Sep 15, 11:25 PM CDTSevere Thunderstorm WarningFGFMarshall, Pennington, Polk50 min
Sep 15, 11:27 PM CDTSpecial Weather StatementFGFMarshall48 min
Sep 15, 11:45 PM CDTSevere Thunderstorm WarningFGFPolk60 min
Sep 16, 12:14 AM CDTSpecial Weather StatementFGFPennington46 min
Sep 16, 12:22 AM CDTSpecial Weather StatementFGFPolk, Red Lake38 min
Sep 16, 12:42 AM CDTSevere Thunderstorm WarningFGFPolk, Red Lake33 min
Sep 16, 1:13 AM CDTSpecial Weather StatementFGFRed Lake32 min
Sep 16, 1:23 AM CDTSpecial Weather StatementFGFMahnomen37 min
Sep 16, 1:51 AM CDTSpecial Weather StatementFGFBeltrami, Clearwater54 min
Sep 16, 2:44 AM CDTSpecial Weather StatementFGFHubbard46 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.