Alert archive / South Dakota / Tornado Warnings in 2021

Tornado Warning 5, NWS Rapid City, SD

May 23, 2021Custer County, South Dakota

NWS Rapid City, SD issued this tornado warning at May 23, 2021, 3:59 PM MDT for Custer County, South Dakota. It was in force for 31 min. 9 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: May 23, 2021, 3:59 PM MDT (21:59 UTC)
Expired: May 23, 2021, 4:30 PM MDT
In force: 31 min
Issued by: NWS Rapid City, SD
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

County Custer County, SD

The radar

The Rapid City radar (KUDX), 70 km from the middle of the area, began a volume at 22:02 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
May 23, 4:00 PM MDT	TSTM WND DMG	5 N Pringle, SD	OVER 100 TREES DOWN
May 23, 4:00 PM MDT	TORNADO	5 N Pringle, SD	BASED ON PICTURES, THE TREE DAMAGE APPEARS TO BE CAUSED BY A TORNADO.
May 23, 4:02 PM MDT	HAIL 1.25	1 Ssw Custer, SD
May 23, 4:04 PM MDT	TORNADO	2 Ne Custer, SD	NUMEROUS TREES SNAPPED AND UPROOTED. RATING EF1. PATH LENGTH 5.4 MILES.
May 23, 4:05 PM MDT	TSTM WND GST 68	2 Ssw Custer, SD
May 23, 4:08 PM MDT	HAIL 0.75	1 Ene Custer, SD
May 23, 4:10 PM MDT	TSTM WND DMG	4 Ne Custer, SD	TREES DOWN ON ROCKY ROAD
May 23, 4:10 PM MDT	TSTM WND DMG	5 Ene Custer, SD	MULTIPLE TREES DOWN. DELAYED REPORT. TIME ESTIMATED FROM RADAR.
May 23, 4:30 PM MDT	TSTM WND DMG	Hermosa, SD	TWO TREES DOWN. DELAYED REPORT. TIME ESTIMATED FROM RADAR.

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
May 23, 1:50 PM MDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 10.0 hours before the alert went out and 64 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 549 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 271 m²/s²
0-3 km storm-relative helicity: 339 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

806 
WFUS53 KUNR 232159
TORUNR
SDC033-232230-
/O.NEW.KUNR.TO.W.0005.210523T2159Z-210523T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Rapid City SD
359 PM MDT Sun May 23 2021

The National Weather Service in Rapid City has issued a

* Tornado Warning for...
  North central Custer County in southwestern South Dakota...

* Until 430 PM MDT.

* At 359 PM MDT, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located 4
  miles south of Custer, moving northeast at 40 mph.

  HAZARD...Tornado and quarter size hail.

  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...
  Stockade Lake and Mount Coolidge around 405 PM MDT.
  Legion Lake, State Game Lodge and Custer State Park around 410 PM 
  MDT.
  Black Hills Playhouse and Center Lake around 415 PM MDT.

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 4370 10373 4386 10351 4386 10313 4358 10354
TIME...MOT...LOC 2159Z 219DEG 36KT 4371 10358 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Carstens

2 follow-up statements

007 
WWUS53 KUNR 232206
SVSUNR

Severe Weather Statement
National Weather Service Rapid City SD
406 PM MDT Sun May 23 2021

SDC033-232230-
/O.CON.KUNR.TO.W.0005.000000T0000Z-210523T2230Z/
Custer SD-
406 PM MDT Sun May 23 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 430 PM MDT FOR NORTH
CENTRAL CUSTER COUNTY...

At 406 PM MDT, a severe squall line capable of producing both
tornadoes and extensive straight line wind damage was located over
northwestern Custer State Park, or 5 miles east of Custer, moving
northeast at 45 mph.

HAZARD...Tornado and quarter size hail.

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...
  Center Lake, Black Hills Playhouse and State Game Lodge around 410 
  PM MDT.

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 4375 10358 4386 10351 4386 10319 4368 10353
TIME...MOT...LOC 2206Z 222DEG 40KT 4377 10349 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Carstens

286 
WWUS53 KUNR 232221
SVSUNR

Severe Weather Statement
National Weather Service Rapid City SD
421 PM MDT Sun May 23 2021

SDC033-232230-
/O.EXP.KUNR.TO.W.0005.000000T0000Z-210523T2230Z/
Custer SD-
421 PM MDT Sun May 23 2021

...THE TORNADO WARNING FOR NORTH CENTRAL CUSTER COUNTY WILL EXPIRE AT
430 PM MDT...
    
The tornado threat has diminished and the Tornado Warning has been
cancelled. However, large hail and damaging winds remain likely and a
Severe Thunderstorm Warning remains in effect for the area. 

A Tornado Watch remains in effect until 900 PM MDT for southwestern
and west central South Dakota.

Remember, a Severe Thunderstorm Warning still remains in effect for
central Custer County until 430 pm MDT.

LAT...LON 4375 10358 4386 10351 4386 10319 4368 10353
TIME...MOT...LOC 2220Z 219DEG 36KT 4387 10338 

$$

Carstens

The office that day

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

Issued	Product	Office	Counties	Lasted
May 23, 3:20 AM MDT	Special Weather Statement	UNR	Oglala Lakota	40 min
May 23, 4:57 AM MDT	Special Weather Statement	UNR	Meade	33 min
May 23, 5:23 AM MDT	Special Weather Statement	UNR	Jackson	37 min
May 23, 1:40 PM MDT	Special Weather Statement	UNR	Fall River	35 min
May 23, 2:00 PM MDT	Special Weather Statement	UNR	Custer	30 min
May 23, 2:02 PM MDT	Special Weather Statement	UNR	Meade	28 min
May 23, 2:16 PM MDT	Special Weather Statement	UNR	Pennington	29 min
May 23, 2:45 PM MDT	Tornado Warning	UNR	Meade	30 min
May 23, 3:13 PM MDT	Tornado Warning	UNR	Meade, Perkins	47 min
May 23, 3:34 PM MDT	Special Weather Statement	UNR	Fall River	26 min
May 23, 3:53 PM MDT	Severe Thunderstorm Warning	UNR	Custer	37 min
May 23, 3:58 PM MDT	Tornado Warning	UNR	Perkins	47 min
May 23, 4:14 PM MDT	Tornado Warning	UNR	Custer, Pennington	13 min
May 23, 4:26 PM MDT	Severe Thunderstorm Warning	UNR	Custer, Lawrence, Meade, Pennington	49 min
May 23, 4:26 PM MDT	Severe Thunderstorm Warning	UNR	Butte, Meade, Pennington	33 min
May 23, 5:04 PM MDT	Severe Thunderstorm Warning	UNR	Butte, Meade, Pennington	30 min
May 23, 5:35 PM MDT	Special Weather Statement	UNR	Perkins	40 min
May 23, 5:53 PM MDT	Severe Thunderstorm Warning	UNR	Haakon, Meade, Pennington, Ziebach	67 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.