Alert archive / Minnesota / Tornado Warnings in 2021

Tornado Warning 16, NWS Sioux Falls, SD

August 28, 2021Cottonwood County, Minnesota

NWS Sioux Falls, SD issued this tornado warning at Aug 28, 2021, 6:01 PM CDT for Cottonwood County, Minnesota. It was in force for 30 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 28, 2021, 6:01 PM CDT (23:01 UTC)
Expired: Aug 28, 2021, 6:31 PM CDT
In force: 30 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Cottonwood County, MN

The radar

The Sioux Falls radar (KFSD), 136 km from the middle of the area, began a volume at 23:03 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

Time	Report	Where	Remark
Aug 28, 6:03 PM CDT	TSTM WND DMG	Jeffers, MN	LARGE TREE, ROUGHLY ONE TO TWO FEET IN DIAMETER, SNAPPED IN HALF. PICTURE VIA SOCIAL MEDIA.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 28, 3:44 PM CDT	Tornado Watch	SPC	5 hr
Aug 28, 3:57 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.0 hours before the alert went out and 152 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1550 J/kg
Mixed-layer CIN: -130 J/kg
Mixed-layer LCL: 676 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 139 m²/s²
0-3 km storm-relative helicity: 193 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted.

078 
WFUS53 KFSD 282301
TORFSD
MNC033-282345-
/O.NEW.KFSD.TO.W.0016.210828T2301Z-210828T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
601 PM CDT Sat Aug 28 2021

The National Weather Service in Sioux Falls has issued a

* Tornado Warning for...
  Northern Cottonwood County in southwestern Minnesota...

* Until 645 PM CDT.

* At 601 PM CDT, severe thunderstorms capable of producing both 
  tornadoes and extensive straight line wind damage were located 
  just north of Storden, or 16 miles northwest of Windom, moving 
  northeast at 50 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* These dangerous storms will be near...
  Jeffers around 605 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4397 9542 4420 9546 4419 9511 4411 9510
      4410 9486 4401 9486
TIME...MOT...LOC 2301Z 244DEG 43KT 4408 9528 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Kalin

2 follow-up statements

073 
WWUS53 KFSD 282325
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
625 PM CDT Sat Aug 28 2021

MNC033-282345-
/O.CON.KFSD.TO.W.0016.000000T0000Z-210828T2345Z/
Cottonwood MN-
625 PM CDT Sat Aug 28 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR NORTHERN
COTTONWOOD COUNTY...

At 624 PM CDT, a severe squall line capable of producing both
tornadoes and extensive straight line wind damage was located near
Springfield, or 21 miles north of Windom, moving northeast at 35 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornadic thunderstorm will remain over mainly rural areas of
northern Cottonwood County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4404 9511 4420 9546 4419 9511 4411 9510
      4410 9486 4401 9486
TIME...MOT...LOC 2324Z 241DEG 29KT 4418 9502 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Kalin

313 
WWUS53 KFSD 282331
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
631 PM CDT Sat Aug 28 2021

MNC033-282340-
/O.CAN.KFSD.TO.W.0016.000000T0000Z-210828T2345Z/
Cottonwood MN-
631 PM CDT Sat Aug 28 2021

...THE TORNADO WARNING FOR NORTHERN COTTONWOOD COUNTY IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota.

LAT...LON 4404 9511 4420 9546 4419 9511 4411 9510
      4410 9486 4401 9486
TIME...MOT...LOC 2329Z 244DEG 43KT 4421 9492 

$$

Kalin

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 4:45 PM CDT	Tornado Warning	FSD	Rock	30 min
Aug 28, 4:49 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Nobles, Rock	41 min
Aug 28, 5:00 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Nobles, Rock	45 min
Aug 28, 5:06 PM CDT	Tornado Warning	FSD	Murray, Nobles, Pipestone, Rock	24 min
Aug 28, 5:24 PM CDT	Tornado Warning	FSD	Nobles	36 min
Aug 28, 5:26 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Cottonwood, Jackson, Murray, Nobles, Pipestone, Rock	34 min
Aug 28, 5:26 PM CDT	Tornado Warning	FSD	Cottonwood, Murray	34 min
Aug 28, 5:29 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Cottonwood, Jackson, Murray, Nobles, Pipestone, Rock	31 min
Aug 28, 5:34 PM CDT	Severe Thunderstorm Warning	FSD	Rock	17 min
Aug 28, 5:43 PM CDT	Tornado Warning	FSD	Cottonwood, Murray	32 min
Aug 28, 5:45 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Cottonwood, Jackson, Murray, Nobles	45 min
Aug 28, 5:49 PM CDT	Tornado Warning	FSD	Cottonwood, Jackson, Murray, Nobles	26 min
Aug 28, 6:15 PM CDT	Severe Thunderstorm Warning	FSD	Pipestone, Rock	45 min
Aug 28, 6:53 PM CDT	Severe Thunderstorm Warning	FSD	Rock	52 min

Nearby

Tornado Warnings in Minnesota, 2021 Every tornado warning in 2021 Tornadoes 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.