Alert archive / South Dakota / Mesoscale Discussions in 2021
Mesoscale Discussion 611
The Storm Prediction Center issued this mesoscale discussion at May 14, 2021, 4:58 PM CDT for Lyon County, Iowa; 14 counties in Minnesota; 21 counties in South Dakota. It was in force for 92 min.
The area
The outline as issued.
The facts
- Issued
- May 14, 2021, 4:58 PM CDT (21:58 UTC)
- Expired
- May 14, 2021, 6:30 PM CDT
- In force
- 92 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 36 counties
Lyon County, IA, Big Stone County, MN, Chippewa County, MN, Douglas County, MN, Grant County, MN, Lac qui Parle County, MN, Lincoln County, MN, Lyon County, MN, Pipestone County, MN, Pope County, MN, Rock County, MN, Stevens County, MN, Swift County, MN, Traverse County, MN, Yellow Medicine County, MN, Brookings County, SD, Clay County, SD, Codington County, SD, Davison County, SD, Deuel County, SD, Douglas County, SD, Grant County, SD, Hamlin County, SD, Hanson County, SD, Hutchinson County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Roberts County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Sioux Falls radar (KFSD), 92 km from the middle of the area, began a volume at 21:59 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
Aberdeen, SD (KABR), launched 12:00Z, 10.0 hours before the alert went out and 124 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
- 1771 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 101 m²/s²
- 0-3 km storm-relative helicity
- 92 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
030
ACUS11 KWNS 142159
SWOMCD
SPC MCD 142158
MNZ000-IAZ000-SDZ000-NDZ000-NEZ000-142330-
Mesoscale Discussion 0611
NWS Storm Prediction Center Norman OK
0458 PM CDT Fri May 14 2021
Areas affected...Eastern SD...Southwest MN...Extreme northwest IA
Concerning...Severe potential...Watch unlikely
Valid 142158Z - 142330Z
Probability of Watch Issuance...5 percent
SUMMARY...A few strong thunderstorms are possible into early
evening, with some threat of hail and strong wind gusts.
DISCUSSION...A cluster of thunderstorms has recently developed
across extreme west-central MN, near a weak surface low over
northeast SD, with other scattered storms trying to develop
southwestward across eastern SD along a surface trough. While
low-level moisture is generally limited, afternoon heating and
relatively cold temperatures aloft (around -20C) are supporting
SBCAPE of 500-1000 J/kg, per recent objective mesoanalyses. Modest
west-northwesterly midlevel flow is supporting 25-35 kt of effective
shear, which will support the potential for organized multicells or
perhaps a supercell with any sustained convection. The primary
threat will likely be hail, though isolated strong wind gusts will
also be possible in areas where stronger boundary-layer
heating/mixing has occurred.
..Dean/Grams.. 05/14/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...FGF...FSD...OAX...ABR...
LAT...LON 43809816 44829751 45769700 46149670 46279596 46149548
45279533 43949584 42869633 42749702 42969758 43369851
43629847 43809816Nearby
Mesoscale Discussions in South Dakota, 2021Mesoscale Discussions in Minnesota, 2021Mesoscale Discussions in Iowa, 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.