Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 116, NWS Grand Forks, ND

September 16, 2021Polk County, Red Lake County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Sep 16, 2021, 12:42 AM CDT for Polk County, Red Lake County, Minnesota. It was in force for 33 min. 2 reports 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
Sep 16, 2021, 12:42 AM CDT (05:42 UTC)
Expired
Sep 16, 2021, 1:15 AM CDT
In force
33 min
Issued by
NWS Grand Forks, ND
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Polk County, MN, Red Lake County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 94 km from the middle of the area, began a volume at 05:44 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
Sep 16, 12:42 AM CDTHAIL 12 Sse Gentilly, MNPUBLIC REPORT OF HAIL ESTIMATED TO BE AROUND QUARTER SIZED, POSSIBLY UP TO GOLF BALL SIZED BUT COULD NOT CONFIRM.
Sep 16, 12:42 AM CDTHAIL 12 Sse Gentilly, MNREPORT OF HAIL TO BE AROUND QUARTER SIZED, POSSIBLY UP TO GOLF BALL SIZED BUT COULD NOT CONFIRM.

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 00:00Z, 5.7 hours before the alert went out and 227 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.

196 
WUUS53 KFGF 160542
SVRFGF
MNC119-125-160615-
/O.NEW.KFGF.SV.W.0116.210916T0542Z-210916T0615Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Grand Forks ND
1242 AM CDT Thu Sep 16 2021

The National Weather Service in Grand Forks has issued a

* Severe Thunderstorm Warning for...
  Southeastern Red Lake County in northwestern Minnesota...
  East central Polk County in northwestern Minnesota...

* Until 115 AM CDT.

* At 1241 AM CDT, a severe thunderstorm was located near Marcoux, or
  26 miles south of Thief River Falls, moving east at 55 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...
  Marcoux, Perault and Dugdale around 1245 AM CDT.
  Mentor around 1250 AM CDT.
  Terrebonne around 1255 AM CDT.
  Brooks and Plummer around 100 AM CDT.

Other locations in the path of this severe thunderstorm include
Oklee.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4773 9577 4766 9637 4772 9647 4782 9644
      4797 9591
TIME...MOT...LOC 0541Z 249DEG 47KT 4775 9635 

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

$$

Lynch
1 follow-up statement
966 
WWUS53 KFGF 160558
SVSFGF

Severe Weather Statement
National Weather Service Grand Forks ND
1258 AM CDT Thu Sep 16 2021

MNC119-125-160615-
/O.CON.KFGF.SV.W.0116.000000T0000Z-210916T0615Z/
Red Lake MN-Polk MN-
1258 AM CDT Thu Sep 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 AM CDT
FOR CENTRAL RED LAKE AND EAST CENTRAL POLK COUNTIES...

At 1258 AM CDT, a severe thunderstorm was located near Terrebonne, or
22 miles south of Thief River Falls, moving east at 45 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...
  Brooks, Plummer and Oklee.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4773 9577 4769 9614 4777 9624 4789 9620
      4797 9591
TIME...MOT...LOC 0558Z 251DEG 38KT 4780 9609 

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

$$

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, 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, 1:59 AM CDTSevere Thunderstorm WarningFGFBeltrami, Clearwater, Hubbard, Mahnomen, Polk49 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.