Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 10, NWS Rapid City, SD
NWS Rapid City, SD issued this severe thunderstorm warning at May 23, 2021, 3:53 PM MDT for Custer County, South Dakota. It was in force for 37 min. 11 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, 3:53 PM MDT (21:53 UTC)
- Expired
- May 23, 2021, 4:30 PM MDT
- In force
- 37 min
- Issued by
- NWS Rapid City, SD
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County Custer County, SD
The radar
The Rapid City radar (KUDX), 74 km from the middle of the area, began a volume at 21:56 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, 3:55 PM MDT | TORNADO | 4 N Pringle, SD | NUMEROUS TREES SNAPPED AND UPROOTED. RATING EF1. PATH LENGTH 6.5 MILES. PATH WIDTH 20 YARDS. |
| May 23, 4:00 PM MDT | TSTM WND DMG | 5 N Pringle, SD | OVER 100 TREES DOWN |
| May 23, 4:00 PM MDT | TSTM WND GST 60 | Pringle, SD | |
| 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.
Did it verify
Verified. The Iowa Environmental Mesonet's Cow matched 7 storm reports to this severe thunderstorm warning; the first came 7 minutes after it went out.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
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, 9.9 hours before the alert went out and 67 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.
- 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
The text
As transmitted.
799
WUUS53 KUNR 232153
SVRUNR
SDC033-232230-
/O.NEW.KUNR.SV.W.0010.210523T2153Z-210523T2230Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Rapid City SD
353 PM MDT Sun May 23 2021
The National Weather Service in Rapid City has issued a
* Severe Thunderstorm Warning for...
Central Custer County in southwestern South Dakota...
* Until 430 PM MDT.
* At 353 PM MDT, a severe thunderstorm was located over Pringle, or 9
miles south of Custer, moving northeast 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...
Blue Bell around 400 PM MDT.
Legion Lake, Mount Coolidge, Stockade Lake and Buffalo Corrals
around 405 PM MDT.
State Game Lodge, Black Hills Playhouse and Center Lake around 410
PM MDT.
Other locations in the path of this severe thunderstorm include
Hermosa.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 900 PM MDT for southwestern
and west central South Dakota.
&&
LAT...LON 4363 10377 4386 10357 4386 10295 4347 10357
TIME...MOT...LOC 2153Z 227DEG 50KT 4363 10360
HAIL...1.00IN
WIND...60MPH
$$
Carstens2 follow-up statements
565
WWUS53 KUNR 232205
SVSUNR
Severe Weather Statement
National Weather Service Rapid City SD
405 PM MDT Sun May 23 2021
SDC033-232230-
/O.CON.KUNR.SV.W.0010.000000T0000Z-210523T2230Z/
Custer SD-
405 PM MDT Sun May 23 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MDT
FOR CENTRAL CUSTER COUNTY...
At 404 PM MDT, severe thunderstorms were located along a line
extending from near Custer to near Blue Bell to Wind Cave National
Park, moving northeast at 55 mph.
HAZARD...70 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect considerable
tree damage. Wind damage is also likely to mobile homes,
roofs, and outbuildings.
These severe storms will be near...
Legion Lake, Custer State Park, Sylvan Lake and State Game Lodge
around 410 PM MDT.
Other locations in the path of these severe thunderstorms include
Black Hills Playhouse, Center Lake and Hermosa.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 900 PM MDT for southwestern
and west central South Dakota.
&&
LAT...LON 4371 10370 4386 10357 4386 10295 4351 10351
TIME...MOT...LOC 2204Z 216DEG 46KT 4378 10363 4372 10352 4357 10345
TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
$$
Carstens743
WWUS53 KUNR 232215
SVSUNR
Severe Weather Statement
National Weather Service Rapid City SD
415 PM MDT Sun May 23 2021
SDC033-232230-
/O.CON.KUNR.SV.W.0010.000000T0000Z-210523T2230Z/
Custer SD-
415 PM MDT Sun May 23 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MDT
FOR CENTRAL CUSTER COUNTY...
At 415 PM MDT, severe thunderstorms were located along a line
extending from Horse Thief Lake to Custer State Park to 3 miles east
of Buffalo Corrals, moving northeast at 60 mph.
HAZARD...70 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect considerable
tree damage. Wind damage is also likely to mobile homes,
roofs, and outbuildings.
Locations impacted include...
Hermosa.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 900 PM MDT for southwestern
and west central South Dakota.
&&
LAT...LON 4386 10357 4386 10295 4356 10345 4378 10364
TIME...MOT...LOC 2215Z 227DEG 50KT 4388 10348 4382 10337 4367 10330
TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
$$
CarstensWhat forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Rapid City, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at May 23, 2:11 PM MDT, 1 hour 42 minutes earlier.
Area forecast discussion, May 23, 2:11 PM MDT, 1 hour 42 minutes before
Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 211 PM MDT Sun May 23 2021 .DISCUSSION...(This Evening Through Sunday) Issued at 123 PM MDT Sun May 23 2021 20Z analysis shows a surface low near the Bighorns in northeastern Wyoming with another low pressure center over northeastern Colorado. A surface trough/warm front extends northeastward from that low into western South Dakota, currently extending roughly from Custer to Rapid City to Faith. Extensive low stratus and cooler temperatures remain in place to the northwest of the front in South Dakota, with much warmer temperatures and greater surface based instability to the southeast of the front. Expect to see the front push a little farther to the northwest this afternoon. Upper low over southwestern Montana will swing a shortwave trough across the region, increasing synoptic scale lift and coverage of showers and thunderstorms during the rest of the afternoon and evening. SBCAPE has risen to 1000-2000J/KG in the warm sector to the south of the front and 0-6km bulk shear has increased to 40-60kts. Low LCL heights and SRH values in the range of 200-300m2/s2 exist along and to the north of the front, particularly in northwestern South Dakota. Convective mode may later transition from discrete storms with large hail and possible tornadoes to a squall line/bow echo complex with the potential for significant damaging winds and large hail. Monday will be windy and drier with 30kt west/southwest boundary layer flow. High temperatures will be mainly in the 70s. Rest of week looks like typical late May weather. Showers/storms possible mid-week and then next weekend as a couple of disturbances move along the US/Canadian border. && .AVIATION...(For the 18Z TAFS Through 18Z Monday) Issued At 1110 AM MDT Sun May 23 2021 MVFR/IFR/LIFR conditions in low clouds/fog are expected to improve early this afternoon. Then a round of showers/storms will develop across northeastern WY and much of western SD. This activity will evolve into a line of strong to severe storms, with damaging winds, large hail, and tornadoes possible. MVFR conditions will be possible in showers/storms. Behind the storms, conditions will improve to VFR overnight. Southwesterly winds will become breezy Monday morning. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && DISCUSSION...10 AVIATION...Pojorlie
Hazardous weather outlook, May 23, 9:26 AM MDT, 6 hours 27 minutes before
Hazardous Weather Outlook National Weather Service Rapid City SD 926 AM MDT Sun May 23 2021 SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058- 071-241300- Harding-Perkins-Butte-Northern Meade Co Plains-Ziebach- Northern Black Hills-Northern Foot Hills-Rapid City- Southern Foot Hills-Central Black Hills-Southern Black Hills- Custer Co Plains-Pennington Co Plains-Haakon-Fall River- Oglala Lakota-Jackson-Bennett-Mellette-Todd-Tripp- Sturgis/Piedmont Foot Hills-Southern Meade Co Plains- Hermosa Foot Hills-Northern Campbell-Southern Campbell- Western Crook-Wyoming Black Hills-Weston-Northeastern Crook- 926 AM MDT Sun May 23 2021 /1026 AM CDT Sun May 23 2021/ This Hazardous Weather Outlook is for portions of western South Dakota and northeastern Wyoming. .DAY ONE...Today and Tonight Numerous to widespread strong to severe thunderstorms are expected this afternoon and evening. Storms will develop over northeastern WY and western SD in the early afternoon, then shift northward and eastward through the afternoon and evening. Damaging straight-line winds, large hail, and tornadoes will all be possible, especially over western SD. Storms will move into central SD late this evening. .DAYS TWO THROUGH SEVEN...Monday through Saturday Chances for thunderstorms return on Wednesday, but widespread severe weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today. && Monitor NOAA Weather Radio for the latest information, forecasts, and warnings.
In the hours before
Special weather statement, May 23, 1:40 PM MDT, 2 hours 13 minutes before
Special Weather Statement National Weather Service Rapid City SD 140 PM MDT Sun May 23 2021 SDZ027-029-041-074-232015- Fall River SD-Hermosa Foot Hills SD-Southern Foot Hills SD- Southern Black Hills SD- 140 PM MDT Sun May 23 2021 ...STRONG THUNDERSTORM OVER SOUTH CENTRAL CUSTER AND NORTH CENTRAL FALL RIVER COUNTIES... At 140 PM MDT, Doppler radar was tracking a strong thunderstorm 3 miles southeast of Cascade Falls, or 9 miles south of Hot Springs, moving north at 40 mph. Half inch hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Hot Springs, southern Wind Cave National Park, Cottonwood Springs Dam, Cascade Falls, Maverick Junction, Cold Brook Reservoir and Angostura Reservoir. PRECAUTIONARY/PREPAREDNESS ACTIONS... This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 4321 10343 4321 10362 4359 10364 4360 10329 TIME...MOT...LOC 1940Z 181DEG 36KT 4330 10350 Eagan
Special weather statement, May 23, 2:00 PM MDT, 1 hour 53 minutes before
Special Weather Statement
National Weather Service Rapid City SD
200 PM MDT Sun May 23 2021
SDZ026-028-029-074-232030-
Hermosa Foot Hills SD-Central Black Hills SD-Southern Black Hills SD-
Rapid City SD-
200 PM MDT Sun May 23 2021
...STRONG THUNDERSTORM OVER NORTH CENTRAL CUSTER AND SOUTH CENTRAL
PENNINGTON COUNTIES...
At 159 PM MDT, Doppler radar was tracking a strong thunderstorm over
eastern Custer State Park, or 11 miles east of Custer, moving north
at 40 mph.
Half inch hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Southwestern Rapid City, Keystone, Hisega, Hayward, Rockerville,
Mount Rushmore National Memorial, Keystone Wye, Bear Country, Hart
Ranch, Legion Lake, State Game Lodge, Center Lake, Custer State Park,
Black Gap, Reptile Gardens, Black Hills Playhouse and Sheridan Lake.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
A Tornado Watch remains in effect until 900 PM MDT for southwestern
and west central South Dakota.
LAT...LON 4371 10348 4407 10346 4401 10311 4400 10310
4368 10333
TIME...MOT...LOC 1959Z 190DEG 37KT 4376 10337
EaganSpecial weather statement, May 23, 2:02 PM MDT, 1 hour 51 minutes before
Special Weather Statement National Weather Service Rapid City SD 202 PM MDT Sun May 23 2021 SDZ013-031-073-232030- Pennington Co Plains SD-Southern Meade Co Plains SD- Northern Meade Co Plains SD- 202 PM MDT Sun May 23 2021 ...STRONG THUNDERSTORM OVER SOUTHEASTERN MEADE AND NORTHEASTERN PENNINGTON COUNTIES... At 201 PM MDT, Doppler radar was tracking a strong thunderstorm 9 miles north of Creighton, or 37 miles northwest of Philip, moving north at 45 mph. Nickel size hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Plainview and Marcus. PRECAUTIONARY/PREPAREDNESS ACTIONS... This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && A Tornado Watch remains in effect until 900 PM MDT for west central South Dakota. LAT...LON 4430 10218 4431 10236 4471 10241 4470 10204 TIME...MOT...LOC 2001Z 179DEG 41KT 4438 10226 Eagan
Special weather statement, May 23, 2:16 PM MDT, 1 hour 37 minutes before
Special Weather Statement
National Weather Service Rapid City SD
216 PM MDT Sun May 23 2021
SDZ026-031-073-232045-
Pennington Co Plains SD-Southern Meade Co Plains SD-Rapid City SD-
216 PM MDT Sun May 23 2021
...STRONG THUNDERSTORM OVER SOUTH CENTRAL MEADE AND CENTRAL
PENNINGTON COUNTIES...
At 216 PM MDT, Doppler radar was tracking a strong thunderstorm 3
miles southeast of Box Elder, or 9 miles east of Rapid City, moving
north at 45 mph.
Pea to dime size hail and winds in excess of 40 mph will be possible
with this storm.
Locations impacted include...
Eastern Rapid Valley, Ellsworth Air Force Base, Box Elder, Hereford
and Rapid City Airport.
This includes Interstate 90 in South Dakota between Mile Markers 63
and 71.
A Tornado Watch remains in effect until 900 PM MDT for west central
South Dakota.
LAT...LON 4414 10314 4415 10312 4417 10314 4440 10319
4440 10287 4401 10301 4401 10311
TIME...MOT...LOC 2016Z 179DEG 39KT 4409 10304
EaganSpecial weather statement, May 23, 3:34 PM MDT, 19 minutes before
Special Weather Statement National Weather Service Rapid City SD 334 PM MDT Sun May 23 2021 SDZ027-029-041-074-232200- Fall River SD-Hermosa Foot Hills SD-Southern Foot Hills SD- Southern Black Hills SD- 334 PM MDT Sun May 23 2021 ...STRONG THUNDERSTORM OVER SOUTH CENTRAL CUSTER AND NORTHWESTERN FALL RIVER COUNTIES... At 334 PM MDT, Doppler radar was tracking a strong thunderstorm 6 miles north of Edgemont, moving northeast at 45 mph. Penny size hail and wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Hot Springs, Edgemont, Argyle, Wind Cave National Park, Cottonwood Springs Dam, Cascade Falls, Maverick Junction, Cold Brook Reservoir and Angostura Reservoir. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. If on or near Angostura Reservoir, get out of the water and move indoors or inside a vehicle. Remember, lightning can strike out to 10 miles from the parent thunderstorm. If you can hear thunder, you are close enough to be struck by lightning. Move to safe shelter now! Do not be caught on the water in a thunderstorm. && A Tornado Watch remains in effect until 900 PM MDT for southwestern South Dakota. LAT...LON 4325 10381 4343 10396 4365 10345 4328 10326 TIME...MOT...LOC 2134Z 240DEG 41KT 4339 10379 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, 3:58 PM MDT | Tornado Warning | UNR | Perkins | 47 min |
| May 23, 3:59 PM MDT | Tornado Warning | UNR | Custer | 31 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
Severe Thunderstorm Warnings in South Dakota, 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.