Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 211, NWS Rapid City, SD
NWS Rapid City, SD issued this severe thunderstorm warning at Aug 31, 2021, 1:57 AM CDT for Mellette County, Todd County, Tripp County, South Dakota. It was in force for 63 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
- Aug 31, 2021, 1:57 AM CDT (06:57 UTC)
- Expired
- Aug 31, 2021, 3:00 AM CDT
- In force
- 63 min
- Issued by
- NWS Rapid City, SD
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Mellette County, SD, Todd County, SD, Tripp County, SD
The radar
The North Platte radar (KLNX), 154 km from the middle of the area, began a volume at 06:57 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 31, 2:10 AM CDT | TSTM WND GST 56 | 15 Sse Mission, SD | |
| Aug 31, 2:15 AM CDT | TSTM WND GST 60 | 4 Nnw Keyapaha, SD | DELAYED REPORT. POWER OUT FOR ABOUT THREE HOURS. ALSO TWO INCHES OF RAINFALL. TIME ESTIMATED FROM RADAR. |
| Aug 31, 2:50 AM CDT | TSTM WND GST 52 | Wewela, SD |
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 one storm report to this severe thunderstorm warning; the first came 18 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 |
|---|---|---|---|
| Aug 30, 9:57 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Aberdeen, SD (KABR), launched 00:00Z, 7.0 hours before the alert went out and 226 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
- 205 J/kg
- Mixed-layer CIN
- -60 J/kg
- Mixed-layer LCL
- 1953 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- 126 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
413
WUUS53 KUNR 310657
SVRUNR
SDC095-121-123-310800-
/O.NEW.KUNR.SV.W.0211.210831T0657Z-210831T0800Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Rapid City SD
157 AM CDT Tue Aug 31 2021
The National Weather Service in Rapid City has issued a
* Severe Thunderstorm Warning for...
Eastern Todd County in south central South Dakota...
Tripp County in south central South Dakota...
Southeastern Mellette County in south central South Dakota...
* Until 300 AM CDT.
* At 157 AM CDT, severe thunderstorms were located along a line
extending from 6 miles north of Mosher to near Hidden Timber to 8
miles east of Kilgore, moving east at 45 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.
* Severe thunderstorms will be near...
Mosher and Hidden Timber around 200 AM CDT.
Sicangu Village around 210 AM CDT.
Witten around 215 AM CDT.
Other locations in the path of these severe thunderstorms include
Keyapaha, Ideal, Clearfield, Winner, Millboro, Ideal South Housing,
Dog Ear Lake and Wewela.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4300 10096 4332 10059 4365 10049 4352 9962
4350 9962 4350 9954 4299 9954
TIME...MOT...LOC 0657Z 291DEG 36KT 4356 10029 4322 10040 4295 10078
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Richards3 follow-up statements
239
WWUS53 KUNR 310722
SVSUNR
Severe Weather Statement
National Weather Service Rapid City SD
222 AM CDT Tue Aug 31 2021
SDC095-121-123-310800-
/O.CON.KUNR.SV.W.0211.000000T0000Z-210831T0800Z/
Todd SD-Tripp SD-Mellette SD-
222 AM CDT Tue Aug 31 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 AM CDT
FOR EASTERN TODD...TRIPP AND SOUTHEASTERN MELLETTE COUNTIES...
At 222 AM CDT, severe thunderstorms were located along a line
extending from 6 miles east of Witten to 3 miles southeast of
Keyapaha to 11 miles west of Norden, moving southeast at 45 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Millboro, Winner, Ideal South Housing, Wewela and Colome.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4300 10054 4312 10041 4355 10030 4346 9954
4299 9954
TIME...MOT...LOC 0722Z 300DEG 40KT 4345 9996 4308 10007 4281 10029
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Richards006
WWUS53 KUNR 310740
SVSUNR
Severe Weather Statement
National Weather Service Rapid City SD
240 AM CDT Tue Aug 31 2021
SDC095-121-310749-
/O.CAN.KUNR.SV.W.0211.000000T0000Z-210831T0800Z/
Todd SD-Mellette SD-
240 AM CDT Tue Aug 31 2021
...THE SEVERE THUNDERSTORM WARNING FOR EASTERN TODD AND SOUTHEASTERN
MELLETTE COUNTIES IS CANCELLED...
The storms which prompted the warning have moved out of the warned
area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 500 AM CDT for
south central South Dakota.
LAT...LON 4300 10013 4344 9999 4338 9954 4299 9954
TIME...MOT...LOC 0739Z 288DEG 34KT 4327 9980 4304 9985 4274 10005
$$
SDC123-310800-
/O.CON.KUNR.SV.W.0211.000000T0000Z-210831T0800Z/
Tripp SD-
240 AM CDT Tue Aug 31 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 AM CDT
FOR SOUTHEASTERN TRIPP COUNTY...
At 239 AM CDT, severe thunderstorms were located along a line
extending from 4 miles west of Colome to 4 miles northwest of Wewela
to 9 miles south of Norden, moving east at 40 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Winner, Colome, Millboro, Ideal South Housing, Clearfield, Wewela and
Dog Ear Lake.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4300 10013 4344 9999 4338 9954 4299 9954
TIME...MOT...LOC 0739Z 288DEG 34KT 4327 9980 4304 9985 4274 10005
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Richards311
WWUS53 KUNR 310759
SVSUNR
Severe Weather Statement
National Weather Service Rapid City SD
259 AM CDT Tue Aug 31 2021
SDC123-310809-
/O.EXP.KUNR.SV.W.0211.000000T0000Z-210831T0800Z/
Tripp SD-
259 AM CDT Tue Aug 31 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN TRIPP COUNTY WILL
EXPIRE AT 300 AM CDT...
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire.
A Severe Thunderstorm Watch remains in effect until 500 AM CDT for
south central South Dakota.
LAT...LON 4300 10013 4344 9999 4338 9954 4299 9954
TIME...MOT...LOC 0759Z 291DEG 36KT 4321 9960 4298 9965 4268 9985
$$
RichardsWhat 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 Aug 31, 12:01 AM CDT, 1 hour 56 minutes earlier.
Area forecast discussion, Aug 31, 12:01 AM CDT, 1 hour 56 minutes before
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1101 PM MDT Mon Aug 30 2021
.DISCUSSION...(This Evening Through Monday)
Issued at 227 PM MDT Mon Aug 30 2021
Vis/IR imagery this aftn shows deepening cu across the Black Hills,
with some glaciated updrafts apparent based on the day cloud phase
RGB. These updrafts do appear to be struggling in recent minutes,
potentially as a result of a deep layer of dry air atop a shallow
but moist BL sampled by 18z KUNR RAOB. With continued convergence
owing to upslope flow along the ern periphery of the hills coupled
with the arrival of a subtle midlevel wave passing east of the
Bighorns per WV, think sustained convection will become increasingly
likely by mid-aftn. A second cu field extends from swrn ND/nwrn SD
thru s cntrl SD along an axis of enhanced satellite-derived 850-700
mb PWATs and sfc dew points of 60-65 F.
Given a broad unstable sector across wrn/cntrl SD characterized by
MLCAPE of 1.5-3 kJ/kg, effective bulk shear of 35-40 kt (locally
enhanced near the Black Hills), midlevel lapse rates of 7-8 K/km,
and DCAPE in excess of 1000 J/kg, any sustained updraft will have
the potential of developing supercell characteristics. Fairly
straight-line hodographs will support splitting supercells, as well,
with primarily a large hail threat in left movers and large hail,
damaging wind, and potentially locally heavy rain threats in the
slow-moving right movers. As aformentioned wave approaches, could
see coverage of convection expand, particularly from nwrn to s cntrl
SD. Further upscale growth is likely across cntrl/s cntrl SD this
evening as LLJ strengthens and MUCAPE increases. Cannot rule out a
tornado threat as low-level shear/hodograph curvature increases this
evening. Would not be a surprise if elevated severe storms capable
of large hail persisted into the night given strong WAA/LLJ forcing
and favorable thermodynamic/kinematic profiles. With above normal
PWATs, if we do see upscale growth in the vicinity of the LLJ
tonight, will have to monitor potential for training/locally heavy
rainfall, mainly over s cntrl SD.
Shortwave ridging builds across the High Plains tomorrow, leading to
generally very warm/hot and dry conditions. A dryline will mix
eastward thru nern WY by late AM/early PM, bringing the potential
for critical fire weather conditions (more below in the Fire Wx
section). Broader mid-upper trof and attendant front approach the
area Tuesday night/Wednesday and slowly cross the region thru the
remainder of the week, bringing slightly cooler and more unsettled
conditions.
&&
.AVIATION...(For the 06Z TAFS Through 06Z Tuesday Night)
Issued At 1030 PM MDT Mon Aug 30 2021
Thunderstorms will move out of south central SD and diminish by
09Z or so. Several models are showing low stratus spreading over
much of the western SD plains, lasting into mid to late morning.
Conditions will be favorable for the development of fog around the
southern Black Hills, also diminishing mid morning. MVFR/IFR
conditions in low stratus/fog will improve to VFR by midday, when
skies will clear.
&&
.FIRE WEATHER...
Issued at 227 PM MDT Mon Aug 30 2021
Hot and dry conditions are anticipated across northeastern WY
tomorrow behind a dryline. Relative humidity values will fall into
the single digits as temperatures climb into the low to mid 90s.
Confidence in the strength of winds behind the dryline remains
relatively low; thus, have maintained the Fire Weather Watch at
this time.
As noted in the prior discussion, depending on the eastward
advancement of the dryline tomorrow and the strength of winds in
its wake, critical fire weather conditions may be possible as far
east as southwestern SD. However, confidence is higher in the
potential across northeastern WY for now.
Slightly cooler and less dry conditions are expected for the rest
of the week, with multiple chances for precipitation.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...Fire Weather Watch from Tuesday morning through Tuesday evening
for WYZ314>317.
&&
DISCUSSION...Sherburn
AVIATION...Pojorlie
FIRE WEATHER...SherburnHazardous weather outlook, Aug 30, 6:31 AM CDT, 19 hours 26 minutes before
Hazardous Weather Outlook National Weather Service Rapid City SD 531 AM MDT Mon Aug 30 2021 WYZ054>058-071-311145- Northern Campbell-Southern Campbell-Western Crook- Wyoming Black Hills-Weston-Northeastern Crook- 531 AM MDT Mon Aug 30 2021 This Hazardous Weather Outlook is for portions of northeast Wyoming...and the Black Hills of Wyoming. .DAY ONE...Today and Tonight A few thunderstorms are possible this afternoon, with a strong storm or two possible. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Non-severe thunderstorms are possible on Wednesday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today. && Stay tuned to NOAA weather radio for further updates...or check our web site at weather.gov/rapidcity SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-311145- 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- 531 AM MDT Mon Aug 30 2021 /631 AM CDT Mon Aug 30 2021/ This Hazardous Weather Outlook is for portions of western South Dakota and northeastern Wyoming. .DAY ONE...Today and Tonight There is a slight risk of severe thunderstorms late this afternoon and evening, with large hail and damaging winds being the main threats. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday There is a marginal risk of severe thunderstorms on Wednesday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today. && Stay tuned to NOAA weather radio for further updates...or check our web site at weather.gov/rapidcity
In the hours before
Special weather statement, Aug 31, 12:06 AM CDT, 1 hour 51 minutes before
Special Weather Statement
National Weather Service Rapid City SD
1106 PM MDT Mon Aug 30 2021
SDZ032-043-046-310600-
Jackson SD-Haakon SD-Mellette SD-
1106 PM MDT Mon Aug 30 2021
...A strong thunderstorm will impact portions of southeastern Haakon,
northwestern Mellette and northeastern Jackson Counties through
MIDNIGHT MDT/100 AM CDT/...
At 1106 PM MDT/1206 AM CDT/, Doppler radar was tracking a strong
thunderstorm 5 miles southwest of Nowlin, or 12 miles northeast of
Kadoka, moving southeast at 35 mph.
HAZARD...Wind gusts up to 50 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Kadoka, Norris, Midland, Belvidere, Cedar Butte, Black Pipe, Corn
Creek, Nowlin and Intersection of Highway 73 and White River.
This includes Interstate 90 in South Dakota between Mile Markers 145
and 174.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Severe Thunderstorm Watch remains in effect until 400 AM MDT/500 AM
CDT/ for south central, southwestern and west central South Dakota.
&&
LAT...LON 4392 10174 4422 10118 4417 10116 4416 10106
4414 10104 4386 10106 4384 10102 4385 10099
4381 10096 4383 10093 4379 10089 4375 10079
4344 10120
TIME...MOT...LOC 0506Z 314DEG 28KT 4399 10137
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH
HelgesonLocal storm report, Aug 31, 12:35 AM CDT, 1 hour 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
1135 PM MDT MON AUG 30 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1051 PM TSTM WND GST 3 E PHILIP 44.05N 101.60W
08/30/2021 M51 MPH HAAKON SD ASOS
1110 PM TSTM WND GST 4 E CACTUS FLAT 43.84N 101.82W
08/30/2021 M50 MPH JACKSON SD MESONET
1115 PM TSTM WND GST 4 E CACTUS FLAT 43.84N 101.82W
08/30/2021 M57 MPH JACKSON SD MESONET
1120 PM TSTM WND GST 9 ENE BELVIDERE 43.90N 101.10W
08/30/2021 M56 MPH JACKSON SD MESONET
&&
WFO UNRLocal storm report, Aug 31, 12:37 AM CDT, 1 hour 20 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
1137 PM MDT MON AUG 30 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1125 PM TSTM WND GST 1 NE MIDLAND 44.08N 101.14W
08/30/2021 M65 MPH HAAKON SD MESONET
&&
DYELocal storm report, Aug 31, 12:52 AM CDT, 1 hour 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
1152 PM MDT MON AUG 30 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1140 PM TSTM WND GST 9 ENE BELVIDERE 43.90N 101.10W
08/30/2021 M72 MPH JACKSON SD MESONET
&&
DYELocal storm report, Aug 31, 1:08 AM CDT, 49 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
1208 AM MDT TUE AUG 31 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1140 PM TSTM WND GST 7 E WANBLEE 43.58N 101.52W
08/30/2021 M52 MPH JACKSON SD MESONET
1150 PM TSTM WND GST 9 ENE BELVIDERE 43.90N 101.10W
08/30/2021 M56 MPH JACKSON SD MESONET
&&
WFO UNRLocal storm report, Aug 31, 1:41 AM CDT, 16 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
1241 AM MDT TUE AUG 31 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1209 AM TSTM WND GST 5 SW NEMO 44.14N 103.58W
08/31/2021 M53 MPH LAWRENCE SD MESONET
TIME ESTIMATED BY RADAR
1220 AM TSTM WND GST 11 SW PARMELEE 43.23N 101.20W
08/31/2021 M54 MPH TODD SD MESONET
1220 AM TSTM WND GST 9 ENE BELVIDERE 43.90N 101.10W
08/31/2021 M51 MPH JACKSON SD MESONET
&&
WFO UNRThe office that day
Everything else NWS Rapid City, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 30, 7:42 PM CDT | Severe Thunderstorm Warning | UNR | Meade, Perkins, Ziebach | 63 min |
| Aug 30, 7:56 PM CDT | Severe Thunderstorm Warning | UNR | Perkins | 64 min |
| Aug 30, 8:41 PM CDT | Severe Thunderstorm Warning | UNR | Haakon, Meade, Ziebach | 64 min |
| Aug 30, 9:19 PM CDT | Special Weather Statement | UNR | Perkins | 41 min |
| Aug 30, 9:30 PM CDT | Severe Thunderstorm Warning | UNR | Meade, Pennington | 60 min |
| Aug 30, 9:33 PM CDT | Special Weather Statement | UNR | Ziebach | 42 min |
| Aug 30, 9:40 PM CDT | Severe Thunderstorm Warning | UNR | Ziebach | 40 min |
| Aug 30, 9:46 PM CDT | Severe Thunderstorm Warning | UNR | Haakon, Ziebach | 59 min |
| Aug 30, 10:08 PM CDT | Severe Thunderstorm Warning | UNR | Meade, Perkins | 35 min |
| Aug 30, 10:26 PM CDT | Severe Thunderstorm Warning | UNR | Haakon, Pennington | 64 min |
| Aug 30, 10:35 PM CDT | Special Weather Statement | UNR | Todd | 40 min |
| Aug 30, 11:02 PM CDT | Special Weather Statement | UNR | Tripp | 58 min |
| Aug 30, 11:53 PM CDT | Special Weather Statement | UNR | Todd | 67 min |
| Aug 31, 12:06 AM CDT | Special Weather Statement | UNR | Jackson | 54 min |
| Aug 31, 12:29 AM CDT | Severe Thunderstorm Warning | UNR | Bennett, Jackson, Mellette, Todd | 61 min |
| Aug 31, 1:02 AM CDT | Severe Thunderstorm Warning | UNR | Mellette, Todd, Tripp | 58 min |
| Aug 31, 1:19 AM CDT | Severe Thunderstorm Warning | UNR | Mellette, Todd, Tripp | 56 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.