Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 165, NWS Sioux Falls, SD

September 17, 20215 counties in Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Sep 17, 2021, 1:21 AM CDT for 5 counties in Minnesota. It was in force for 39 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
Sep 17, 2021, 1:21 AM CDT (06:21 UTC)
Expired
Sep 17, 2021, 2:00 AM CDT
In force
39 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Cottonwood County, MN, Jackson County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN

The radar

The Sioux Falls radar (KFSD), 124 km from the middle of the area, began a volume at 06:20 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 17, 1:47 AM CDTTSTM WND DMGMountain Lake, MNSEVERAL 3-4 INCH DIAMETER BRANCHES DOWNED.

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

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 6.4 hours before the alert went out and 250 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, Aberdeen, SD at 00:00Z on 2021-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Aberdeen, SD at 00:00Z on 2021-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -170 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1789 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
-170 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

470 
WUUS53 KFSD 170621
SVRFSD
MNC033-063-083-101-105-170700-
/O.NEW.KFSD.SV.W.0165.210917T0621Z-210917T0700Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
121 AM CDT Fri Sep 17 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Eastern Lyon County in southwestern Minnesota...
  Northern Jackson County in southwestern Minnesota...
  Northern Nobles County in southwestern Minnesota...
  Eastern Murray County in southwestern Minnesota...
  Cottonwood County in southwestern Minnesota...

* Until 200 AM CDT.

* At 120 AM CDT, severe thunderstorms were located along a line
  extending from near Echo to near Walnut Grove to 7 miles northwest
  of Worthington, moving east at 55 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Jeffers around 135 AM CDT.
  Heron Lake around 140 AM CDT.

Other locations in the path of these severe thunderstorms include
Comfrey and Bergen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4420 9559 4419 9511 4411 9510 4411 9486
      4377 9485 4376 9593 4415 9576 4463 9572
      4463 9561
TIME...MOT...LOC 0620Z 265DEG 46KT 4458 9546 4416 9545 4372 9568 

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

$$

SG
2 follow-up statements
269 
WWUS53 KFSD 170632
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
132 AM CDT Fri Sep 17 2021

MNC083-170642-
/O.CAN.KFSD.SV.W.0165.000000T0000Z-210917T0700Z/
Lyon MN-
132 AM CDT Fri Sep 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN LYON COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 4419 9511 4411 9510 4411 9486 4377 9485
      4376 9580 4412 9561 4420 9559
TIME...MOT...LOC 0632Z 270DEG 46KT 4459 9529 4417 9528 4373 9551 

$$

MNC033-063-101-105-170700-
/O.CON.KFSD.SV.W.0165.000000T0000Z-210917T0700Z/
Jackson MN-Nobles MN-Murray MN-Cottonwood MN-
132 AM CDT Fri Sep 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 AM CDT
FOR NORTHERN JACKSON...NORTHEASTERN NOBLES...EASTERN MURRAY AND
COTTONWOOD COUNTIES...

At 132 AM CDT, severe thunderstorms were located along a line
extending from 6 miles east of Echo to near Lamberton to near
Brewster, moving east at 55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

These severe storms will be near...
  Jeffers around 140 AM CDT.

Other locations in the path of these severe thunderstorms include
Comfrey and Bergen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4419 9511 4411 9510 4411 9486 4377 9485
      4376 9580 4412 9561 4420 9559
TIME...MOT...LOC 0632Z 270DEG 46KT 4459 9529 4417 9528 4373 9551 

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

$$

SG
457 
WWUS53 KFSD 170655
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
155 AM CDT Fri Sep 17 2021

MNC033-063-101-105-170704-
/O.EXP.KFSD.SV.W.0165.000000T0000Z-210917T0700Z/
Jackson MN-Nobles MN-Murray MN-Cottonwood MN-
155 AM CDT Fri Sep 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN JACKSON...
NORTHEASTERN NOBLES...EASTERN MURRAY AND COTTONWOOD COUNTIES WILL
EXPIRE AT 200 AM CDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

Remember, a Severe Thunderstorm Warning still remains in effect for 
portions of Jackson and Nobles counties in southwestern Minnesota 
until 230 AM CDT.

LAT...LON 4419 9511 4411 9510 4411 9486 4377 9485
      4376 9580 4412 9561 4420 9559
TIME...MOT...LOC 0654Z 270DEG 46KT 4461 9492 4419 9491 4375 9514 

$$

SG

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 17, 12:10 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDLincoln, Pipestone, Rock35 min
Sep 17, 12:34 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDCottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more56 min
Sep 17, 12:36 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDJackson, Nobles, Rock54 min
Sep 17, 1:23 AM CDTSevere Thunderstorm WarningFSDJackson, Nobles67 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.