Alert archive / South Dakota / Mesoscale Discussions in 2021
Mesoscale Discussion 918
The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2021, 12:52 AM CDT for 10 counties in Nebraska; 23 counties in North Dakota; 41 counties in South Dakota. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- Jun 11, 2021, 12:52 AM CDT (05:52 UTC)
- Expired
- Jun 11, 2021, 1:45 AM CDT
- In force
- 53 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...severe thunderstorm watch likely
- Chance of a watch
- 95%
All 74 counties
Barnes County, ND, Benson County, ND, Cass County, ND, Cavalier County, ND, Dickey County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Nelson County, ND, Pierce County, ND, Ramsey County, ND, Ransom County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Towner County, ND, Walsh County, ND, Wells County, ND, Antelope County, NE, Boyd County, NE, Cedar County, NE, Holt County, NE, Keya Paha County, NE, Knox County, NE, Pierce County, NE, Rock County, NE, Wayne County, NE, Wheeler County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Brown County, SD, Brule County, SD, Buffalo County, SD, Campbell County, SD, Charles Mix County, SD, Clark County, SD, Clay County, SD, Codington County, SD, Davison County, SD, Day County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hughes County, SD, Hutchinson County, SD, Hyde County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lyman County, SD, Marshall County, SD, McCook County, SD, McPherson County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Potter County, SD, Roberts County, SD, Sanborn County, SD, Spink County, SD, Turner County, SD, Walworth County, SD, Yankton County, SD
The radar
The Aberdeen radar (KABR), 26 km from the middle of the area, began a volume at 05:56 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.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Aberdeen, SD (KABR), launched 00:00Z, 5.9 hours before the alert went out and 85 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
- 1337 J/kg
- Mixed-layer CIN
- -37 J/kg
- Mixed-layer LCL
- 2725 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 42 m²/s²
- 0-3 km storm-relative helicity
- 91 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.7
The text
As transmitted.
099
ACUS11 KWNS 110553
SWOMCD
SPC MCD 110552
SDZ000-NDZ000-NEZ000-110645-
Mesoscale Discussion 0918
NWS Storm Prediction Center Norman OK
1252 AM CDT Fri Jun 11 2021
Areas affected...eastern SD/ND and northeast NE
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 110552Z - 110645Z
Probability of Watch Issuance...95 percent
SUMMARY...A line of severe thunderstorms with a history of producing
severe thunderstorm wind gusts and hail will continue spreading
eastward across the Dakotas and parts of northern Nebraska
overnight. New severe thunderstorm watches will be needed in the
next 1-2 hours.
DISCUSSION...Well-organized bowing segments with strong rear-inflow
jets have been noted in radar imagery over the past hour, and have
produced numerous severe wind gust reports. This activity will
continue tracking generally eastward at around 40-50 kt the next
several hours. This should bring these storms to edges of WW 253 and
WW 254 between 07z-08z. Moderate to strong instability remains
downstream across the eastern Dakotas into northeast NE, along with
a southerly 850 mb jet around 35-45 kt. While low level inhibition
exists due to nocturnal cooling of the boundary layer, very steep
lapse rates remain between 2-6 km. As a result, a favorable
thermodynamic and kinematic parameter space should continue to
support a well-organized QLCS capable of severe/damaging gusts into
portions of eastern ND/SD and northeast NE during the overnight
hours.
..Leitman/Thompson.. 06/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FGF...FSD...OAX...ABR...BIS...LBF...UNR...
LAT...LON 48420008 48829965 48929895 48839815 48309761 47169705
45319683 43959664 42769680 41979722 41909820 41919898
42249970 43509988 45520016 48130010 48420008SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 10, 8:28 PM CDT | Mesoscale Discussion | SPC | Arthur, Banner, Blaine, Box Butte, Brown, Cherry and 12 more | 92 min |
| Jun 10, 9:08 PM CDT | Severe Thunderstorm Watch | SPC | Arthur, Banner, Blaine, Box Butte, Brown, Cherry and 12 more | 6 hr |
| Jun 10, 11:07 PM CDT | Mesoscale Discussion | SPC | Box Butte, Dawes, Sheridan, Sioux | 83 min |
| Jun 11, 2:15 AM CDT | Severe Thunderstorm Watch | SPC | Dakota, Dixon | 5 hr |
| Jun 11, 5:36 AM CDT | Severe Thunderstorm Watch | SPC | Antelope, Boone, Burt, Butler, Cedar, Colfax and 22 more | 5 hr |
| Jun 11, 7:28 AM CDT | Mesoscale Discussion | SPC | Boone, Burt, Butler, Cass, Colfax, Cuming and 18 more | 92 min |
| Jun 11, 8:30 AM CDT | Severe Thunderstorm Watch | SPC | Cass, Gage, Jefferson, Johnson, Nemaha, Otoe and 2 more | 7 hr |
| Jun 11, 10:28 AM CDT | Mesoscale Discussion | SPC | Gage, Johnson, Nemaha, Otoe, Pawnee, Richardson | 2 hr |
| Jun 10, 8:30 PM CDT | Mesoscale Discussion | SPC | Billings, Burke, Divide, Golden Valley, McKenzie, Mountrail and 1 more | 2 hr |
| Jun 10, 9:54 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Billings, Bottineau, Bowman, Burke, Burleigh and 24 more | 5 hr |
| Jun 10, 11:21 PM CDT | Mesoscale Discussion | SPC | Bottineau, Burke, Divide, McHenry, McKenzie, Mountrail and 3 more | 114 min |
| Jun 11, 1:58 AM CDT | Severe Thunderstorm Watch | SPC | Barnes, Benson, Cass, Cavalier, Dickey, Eddy and 17 more | 5 hr |
| Jun 11, 4:37 AM CDT | Mesoscale Discussion | SPC | Barnes, Cass, Cavalier, Grand Forks, Griggs, Nelson and 8 more | 83 min |
| Jun 10, 11:50 PM CDT | 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.