Alert archive / South Dakota / Mesoscale Discussions in 2022
Mesoscale Discussion 1237
The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2022, 4:14 PM MDT for 13 counties in South Dakota. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Jun 20, 2022, 4:14 PM MDT (22:14 UTC)
- Expired
- Jun 20, 2022, 5:45 PM MDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 393...395
Counties Bennett County, SD, Edmunds County, SD, Faulk County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Todd County, SD
The radar
The Rapid City radar (KUDX), 161 km from the middle of the area, began a volume at 22:15 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 12:00Z, 10.2 hours before the alert went out and 164 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
- 7 J/kg
- Mixed-layer CIN
- -379 J/kg
- Mixed-layer LCL
- 1196 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 21 m²/s²
- 0-3 km storm-relative helicity
- 38 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
575 ACUS11 KWNS 202215 SWOMCD SPC MCD 202214 SDZ000-NEZ000-202345- Mesoscale Discussion 1237 NWS Storm Prediction Center Norman OK 0514 PM CDT Mon Jun 20 2022 Areas affected...parts of northwestern Nebraska through central South Dakota Concerning...Severe Thunderstorm Watch 393...395... Valid 202214Z - 202345Z The severe weather threat for Severe Thunderstorm Watch 393, 395 continues. SUMMARY...Thunderstorms are expected to intensify and organize further while spreading across the central South Dakota Missouri Valley, including the Pierre vicinity, through 7-9 PM CDT. This may be accompanied by increasing potential for strong to locally severe wind gusts. DISCUSSION...Thunderstorms have been generally maintaining strength as they begin to spread northeast of the Black Hills and Nebraska Panhandle vicinity. Activity is accompanying forcing for ascent with a short wave impulse, and an associated mid-level speed maximum (including 30-50+ kt in the 700-500 mb layer) which is forecast to nose north-northeastward (near/northwest of Valentine NE) through much of central South Dakota by 01-02Z. Although low/mid-level lapse rates within the more moist post-frontal regime are not particularly steep, profiles are supportive of moderate CAPE on the order of 1500-2500 J/kg. Given the background environment flow and shear, northerly to northeasterly inflow of this air probably will support further thunderstorm intensification and organization during the next few hours. As this occurs, the risk for strong convective gusts, including a few exceeding severe limits, seems likely to increase. ..Kerr.. 06/20/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...LBF...UNR... LAT...LON 43800173 44860061 45589891 43479973 42200228 43800173
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 19, 6:09 PM MDT | Severe Thunderstorm Watch | SPC | Butte, Harding, Perkins | 7 hr |
| Jun 20, 11:55 AM MDT | Mesoscale Discussion | SPC | Corson, Dewey, Haakon, Potter, Stanley, Sully and 1 more | 95 min |
| Jun 20, 12:15 PM MDT | Mesoscale Discussion | SPC | Bennett, Custer, Fall River, Haakon, Jackson, Meade and 4 more | 2 hr |
| Jun 20, 12:37 PM MDT | Severe Thunderstorm Watch | SPC | Bennett, Butte, Custer, Fall River, Haakon, Jackson and 9 more | 6 hr |
| Jun 20, 12:49 PM MDT | Mesoscale Discussion | SPC | Brown, Day, Edmunds, McPherson, Marshall, Roberts | 2 hr |
| Jun 20, 2:26 PM MDT | Mesoscale Discussion | SPC | Bennett, Jackson | 2 hr |
| Jun 20, 2:36 PM MDT | Severe Thunderstorm Watch | SPC | Aurora, Beadle, Brookings, Brown, Brule, Buffalo and 36 more | 8 hr |
| Jun 20, 4:59 PM MDT | Mesoscale Discussion | SPC | Bon Homme, Brookings, Deuel, Hanson, Hutchinson, Lake and 3 more | 2 hr |
Nearby
Mesoscale Discussions in South Dakota, 2022Every mesoscale discussion in 2022
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.