Alert archive / South Dakota / Mesoscale Discussions in 2021
Mesoscale Discussion 915
The Storm Prediction Center issued this mesoscale discussion at Jun 10, 2021, 10:07 PM MDT for 4 counties in Nebraska; 6 counties in North Dakota; 14 counties in South Dakota. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- Jun 10, 2021, 10:07 PM MDT (04:07 UTC)
- Expired
- Jun 10, 2021, 11:30 PM MDT
- In force
- 83 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 253...254
All 24 counties
Adams County, ND, Bowman County, ND, Grant County, ND, Hettinger County, ND, Slope County, ND, Stark County, ND, Box Butte County, NE, Dawes County, NE, Sheridan County, NE, Sioux County, NE, Bennett County, SD, Butte County, SD, Corson County, SD, Custer County, SD, Dewey County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD
The radar
The Rapid City radar (KUDX), 60 km from the middle of the area, began a volume at 04:09 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.
The nearest sounding before it
Rapid City, SD (KUNR), launched 00:00Z, 4.1 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
- 1559 J/kg
- Mixed-layer CIN
- -71 J/kg
- Mixed-layer LCL
- 2700 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 88 m²/s²
- 0-3 km storm-relative helicity
- 177 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 15.0
The text
As transmitted.
489
ACUS11 KWNS 110408
SWOMCD
SPC MCD 110407 COR
SDZ000-NEZ000-NDZ000-MTZ000-110530-
Mesoscale Discussion 0915
NWS Storm Prediction Center Norman OK
1107 PM CDT Thu Jun 10 2021
Areas affected...Northwest NE...Western SD...Southwest ND
Concerning...Severe Thunderstorm Watch 253...254...
Valid 110407Z - 110530Z
CORRECTED FOR GEOGRAPHIC HEADLINE
The severe weather threat for Severe Thunderstorm Watch 253, 254
continues.
SUMMARY...Developing thunderstorm clusters will increase the
damaging wind threat through 06Z, with some hail also possible.
DISCUSSION...Storm coverage has increased substantially across
western SD and northwest NE over the last hour, with a few reports
of severe hail and wind already noted across western SD. A
well-defined outflow has emerged across northwest SD, with
additional development noted along its leading flank. Steep midlevel
lapse rates and strong MUCAPE (2500-3500 J/kg) will favor intense
updrafts, even with convection that is slightly elevated behind the
outflow. Additional southward development may occur as the low-level
jet continues to increase and an accelerating cold front moves into
the region.
Increasing midlevel flow and effective shear with time will support
organized convection, and steep lapse rates through a deep layer
just above a nocturnal inversion will favor outflow production and
an increasing threat of more widespread severe wind with time.
Embedded supercell structures capable of hail will also be possible
for at least another 2-3 hours, before convective mode becomes
increasingly linear with time.
..Dean.. 06/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ABR...BIS...LBF...UNR...CYS...BYZ...
LAT...LON 44240082 43590098 42330186 42020342 42160402 42790391
43850363 45050349 45930393 46560419 46840332 46820224
46410133 45850084 44940076 44240082SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 10, 7:28 PM MDT | Mesoscale Discussion | SPC | Arthur, Banner, Blaine, Box Butte, Brown, Cherry and 12 more | 92 min |
| Jun 10, 8:08 PM MDT | Severe Thunderstorm Watch | SPC | Arthur, Banner, Blaine, Box Butte, Brown, Cherry and 12 more | 6 hr |
| Jun 10, 11:52 PM MDT | Mesoscale Discussion | SPC | Antelope, Boyd, Cedar, Holt, Keya Paha, Knox and 4 more | 53 min |
| Jun 11, 1:15 AM MDT | Severe Thunderstorm Watch | SPC | Dakota, Dixon | 5 hr |
| Jun 11, 4:36 AM MDT | Severe Thunderstorm Watch | SPC | Antelope, Boone, Burt, Butler, Cedar, Colfax and 22 more | 5 hr |
| Jun 11, 6:28 AM MDT | Mesoscale Discussion | SPC | Boone, Burt, Butler, Cass, Colfax, Cuming and 18 more | 92 min |
| Jun 11, 7:30 AM MDT | Severe Thunderstorm Watch | SPC | Cass, Gage, Jefferson, Johnson, Nemaha, Otoe and 2 more | 7 hr |
| Jun 11, 9:28 AM MDT | Mesoscale Discussion | SPC | Gage, Johnson, Nemaha, Otoe, Pawnee, Richardson | 2 hr |
| Jun 10, 7:30 PM MDT | Mesoscale Discussion | SPC | Billings, Burke, Divide, Golden Valley, McKenzie, Mountrail and 1 more | 2 hr |
| Jun 10, 8:54 PM MDT | Severe Thunderstorm Watch | SPC | Adams, Billings, Bottineau, Bowman, Burke, Burleigh and 24 more | 5 hr |
| Jun 10, 10:21 PM MDT | Mesoscale Discussion | SPC | Bottineau, Burke, Divide, McHenry, McKenzie, Mountrail and 3 more | 114 min |
| Jun 11, 12:58 AM MDT | Severe Thunderstorm Watch | SPC | Barnes, Benson, Cass, Cavalier, Dickey, Eddy and 17 more | 5 hr |
| Jun 11, 3:37 AM MDT | Mesoscale Discussion | SPC | Barnes, Cass, Cavalier, Grand Forks, Griggs, Nelson and 8 more | 83 min |
| Jun 10, 10:50 PM MDT | Mesoscale Discussion | SPC | Dewey, Haakon, Jackson, Jones, Meade, Mellette and 5 more | 85 min |
Nearby
Mesoscale Discussions in South Dakota, 2021Mesoscale Discussions in North Dakota, 2021Mesoscale Discussions in Nebraska, 2021Every mesoscale discussion 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.