Alert archive / South Dakota / Tornado Warnings in 2021

Tornado Warning 11, NWS Aberdeen, SD

October 9, 2021Brown County, Day County, Marshall County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Oct 9, 2021, 4:57 PM CDT for Brown County, Day County, Marshall County, South Dakota. It was in force for 18 min. 3 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: Oct 9, 2021, 4:57 PM CDT (21:57 UTC)
Expired: Oct 9, 2021, 5:15 PM CDT
In force: 18 min
Issued by: NWS Aberdeen, SD
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Brown County, SD, Day County, SD, Marshall County, SD

The radar

The Aberdeen radar (KABR), 34 km from the middle of the area, began a volume at 21:59 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.

What was reported inside it

Time	Report	Where	Remark
Oct 9, 5:10 PM CDT	TSTM WND GST 66	Andover, SD	CORRECTS PREVIOUS NON-TSTM WND GST REPORT FROM ANDOVER. MESONET STATION 45 ANDOVER (SDDOT).
Oct 9, 5:10 PM CDT	NON-TSTM WND GST 66	Andover, SD	MESONET STATION 45 ANDOVER (SDDOT).
Oct 9, 5:12 PM CDT	TORNADO	3 W Langford, SD

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
Oct 9, 2:56 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 10.0 hours before the alert went out and 74 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: 4 J/kg
Mixed-layer CIN: -89 J/kg
Mixed-layer LCL: 713 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 97 m²/s²
0-3 km storm-relative helicity: 200 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

045 
WFUS53 KABR 092157
TORABR
SDC013-037-091-092215-
/O.NEW.KABR.TO.W.0011.211009T2157Z-211009T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Aberdeen SD
457 PM CDT Sat Oct 9 2021

The National Weather Service in Aberdeen has issued a

* Tornado Warning for...
  Northwestern Day County in northeastern South Dakota...
  Southwestern Marshall County in northeastern South Dakota...
  Southeastern Brown County in northeastern South Dakota...

* Until 515 PM CDT.
    
* At 445 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Groton, moving northeast at 40 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 dangerous storm will be near...
  Andover around 455 PM CDT.
  Pierpont around 505 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Langford.

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 4563 9785 4545 9763 4526 9800 4537 9813
      4546 9832 4567 9812
TIME...MOT...LOC 2145Z 218DEG 34KT 4542 9809 

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

$$

Connelly

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 9, 12:05 PM CDT	Severe Thunderstorm Warning	ABR	Jones, Lyman	27 min
Oct 9, 1:57 PM CDT	Special Weather Statement	ABR	Lyman	33 min
Oct 9, 4:10 PM CDT	Tornado Warning	ABR	Brown, Spink	35 min
Oct 9, 4:30 PM CDT	Tornado Warning	ABR	Brown	15 min
Oct 9, 4:33 PM CDT	Severe Thunderstorm Warning	ABR	Brown, Clark, Codington, Day, Hamlin, Spink	42 min
Oct 9, 4:33 PM CDT	Tornado Warning Tornado observed	ABR	Brown, Day, Spink	27 min
Oct 9, 5:16 PM CDT	Tornado Warning	ABR	Day, Marshall	29 min
Oct 9, 5:17 PM CDT	Tornado Warning	ABR	Brown, Day, Marshall	28 min
Oct 9, 5:18 PM CDT	Severe Thunderstorm Warning	ABR	Brown, Clark, Codington, Day, Grant, Hamlin and 2 more	57 min
Oct 9, 5:44 PM CDT	Tornado Warning	ABR	Brown, Marshall	31 min
Oct 9, 5:47 PM CDT	Tornado Warning	ABR	Day, Marshall, Roberts	28 min
Oct 9, 6:07 PM CDT	Tornado Warning Tornado observed	ABR	Day, Roberts	23 min
Oct 9, 6:14 PM CDT	Tornado Warning	ABR	Marshall, Roberts	31 min
Oct 9, 6:15 PM CDT	Severe Thunderstorm Warning	ABR	Codington, Day, Deuel, Grant, Hamlin, Marshall and 1 more	60 min
Oct 9, 6:28 PM CDT	Tornado Warning	ABR	Roberts	21 min

Nearby

Tornado Warnings in South Dakota, 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.