Alert archive / Minnesota / Mesoscale Discussions in 2021
Mesoscale Discussion 1977
The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2021, 12:27 PM CST for 7 counties in Iowa; 14 counties in Minnesota; 12 counties in South Dakota. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 10, 2021, 12:27 PM CST (18:27 UTC)
- Expired
- Dec 10, 2021, 4:30 PM CST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Heavy snow
All 33 counties
Clay County, IA, Dickinson County, IA, Emmet County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Sioux County, IA, Blue Earth County, MN, Brown County, MN, Cottonwood County, MN, Faribault County, MN, Jackson County, MN, Martin County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Rock County, MN, Waseca County, MN, Watonwan County, MN, Bon Homme County, SD, Clay County, SD, Hanson County, SD, Hutchinson County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Moody County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Sioux Falls radar (KFSD), 38 km from the middle of the area, began a volume at 18:27 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, 6.5 hours before the alert went out and 224 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
- 2000 m above ground
- 0-6 km bulk shear
- 79 kt
- 0-1 km storm-relative helicity
- -67 m²/s²
- 0-3 km storm-relative helicity
- -9 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
614
ACUS11 KWNS 101827
SWOMCD
SPC MCD 101827
MNZ000-IAZ000-SDZ000-NEZ000-102230-
Mesoscale Discussion 1977
NWS Storm Prediction Center Norman OK
1227 PM CST Fri Dec 10 2021
Areas affected...Far Northeast NE...Southeast
SD...Southwest/South-Central MN...Northwest IA
Concerning...Heavy snow
Valid 101827Z - 102230Z
SUMMARY...Snowfall rates are expected to increase from northeast NE
across southeast SD and northwest IA and into southern MN over the
next few hours. One inch per hour rates will be common, with some
isolated areas briefly experiencing two inch per hour rates.
DISCUSSION...Regional radar imagery shows a consolidating band of
moderate to occasionally heavy snowfall stretching from
north-central NE into southern MN. Observational trends and recent
guidance both suggest this band will persist across the region for
the next several hours, with some additional
intensification/organization possible as the western branch of warm
conveyor continues to wrap around the low-level cyclone. This
intensification should lead to a greater prevalence of heavy snow
fall, with 1" per hour rates becoming more common/widespread.
Isolated instances of 2" per hour rates are possible, particularly
later this afternoon in the vicinity of SD/MN/IA border
intersection.
..Mosier.. 12/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...DMX...FSD...OAX...LBF...
LAT...LON 43359842 44169700 44529509 44349351 43629345 42859582
42609834 43359842SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 10, 3:31 PM CST | Mesoscale Discussion | SPC | Clay, Dickinson, Emmet, Kossuth, Lyon, Osceola and 2 more | 4 hr |
| Dec 9, 9:49 PM CST | Mesoscale Discussion | SPC | Bennett, Fall River, Gregory, Todd | 5 hr |
| Dec 10, 2:39 AM CST | Mesoscale Discussion | SPC | Bennett, Custer, Fall River, Jackson, Mellette, Oglala Lakota and 2 more | 4 hr |
| Dec 10, 9:10 AM CST | Mesoscale Discussion | SPC | Aurora, Bon Homme, Brule, Charles Mix, Davison, Douglas and 11 more | 4 hr |
Nearby
Mesoscale Discussions in Minnesota, 2021Mesoscale Discussions in South Dakota, 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.