Alert archive / South Dakota / Mesoscale Discussions in 2011
Mesoscale Discussion 113
The Storm Prediction Center issued this mesoscale discussion at Feb 20, 2011, 9:17 AM CST for 33 counties in Minnesota; 7 counties in North Dakota; 34 counties in South Dakota. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 20, 2011, 9:17 AM CST (15:17 UTC)
- Expired
- Feb 20, 2011, 1:45 PM CST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
All 74 counties
Anoka County, MN, Benton County, MN, Big Stone County, MN, Carver County, MN, Chippewa County, MN, Douglas County, MN, Grant County, MN, Hennepin County, MN, Isanti County, MN, Kanabec County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Lincoln County, MN, Lyon County, MN, McLeod County, MN, Meeker County, MN, Mille Lacs County, MN, Morrison County, MN, Pope County, MN, Ramsey County, MN, Redwood County, MN, Renville County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Traverse County, MN, Wilkin County, MN, Wright County, MN, Yellow Medicine County, MN, Dickey County, ND, Emmons County, ND, McIntosh County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Sioux County, ND, Beadle County, SD, Brookings County, SD, Brown County, SD, Buffalo County, SD, Campbell County, SD, Clark County, SD, Codington County, SD, Corson County, SD, Day County, SD, Deuel County, SD, Dewey County, SD, Edmunds County, SD, Faulk County, SD, Grant County, SD, Haakon County, SD, Hamlin County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jones County, SD, Kingsbury County, SD, Lyman County, SD, Marshall County, SD, McPherson County, SD, Meade County, SD, Mellette County, SD, Perkins County, SD, Potter County, SD, Roberts County, SD, Spink County, SD, Stanley County, SD, Sully County, SD, Walworth County, SD, Ziebach County, SD
The radar
The Aberdeen radar (KABR), 49 km from the middle of the area, began a volume at 15:22 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, 3.3 hours before the alert went out and 36 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
- 656 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 212 m²/s²
- 0-3 km storm-relative helicity
- 442 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
748
ACUS11 KWNS 201517
SWOMCD
SPC MCD 201517
MNZ000-SDZ000-NDZ000-201945-
MESOSCALE DISCUSSION 0113
NWS STORM PREDICTION CENTER NORMAN OK
0917 AM CST SUN FEB 20 2011
AREAS AFFECTED...MUCH OF SD AND FAR SOUTHERN ND TO SOUTH-CENTRAL MN
CONCERNING...HEAVY SNOW
VALID 201517Z - 201945Z
HEAVY SNOWFALL WILL CONTINUE TO DEVELOP/INTENSIFY IN A GENERAL
WEST-EAST CORRIDOR ACROSS SD /MAINLY NORTH OF I-90/ AND EXTREME
SOUTHERN ND INTO SOUTH-CENTRAL MN INCLUDING THE TWIN CITIES.
LOCALIZED SNOWFALL RATES OF 1-2 IN/HR ARE LIKELY...ALONG WITH
BLIZZARD CONDITIONS AT TIMES ESPECIALLY ACROSS PORTIONS OF EASTERN
SD/SOUTHEAST ND AND SOUTHWEST MN.
AS A LEAD SHORTWAVE TROUGH CONTINUES TO PIVOT NORTHEASTWARD OVER THE
NORTHERN HIGH PLAINS...CONSIDERABLE DEEP FORCING FOR ASCENT OWING TO
DPVA...A COUPLED JET ALOFT...AND STRONG LOW LEVEL WARM
ADVECTION/ISENTROPIC LIFT WILL CONTRIBUTE TO A FAVORABLE SCENARIO
FOR HEAVY SNOWFALL WITH AN ARCTIC AIRMASS IN PLACE ACROSS THE
REGION. WITH SLANTWISE/SOME UPRIGHT CAPE AS EVIDENCED BY ONGOING
LIGHTNING THIS MORNING ACROSS FAR SOUTHERN MN/MUCH OF IA...AND STEEP
LAPSE RATES/WEAK ELEVATED BUOYANCY NOTED IN UPSTREAM OBSERVED RAOBS
SUCH AS 12Z RAPID CITY/NORTH PLATTE...PROXIMITY OF WEAK STATIC
STABILITY/STEEPENING LAPSE RATES ALOFT WILL CONTRIBUTE TO ENHANCED
SNOWFALL RATES WITH OTHERWISE FAVORABLE THERMODYNAMIC PROFILES FOR
AMPLE DENDRITIC/AGGREGATE SNOW GROWTH PER 12Z NAM/RUC FORECAST
SOUNDINGS. IN ADDITION...STRONG NORTHEASTERLY WINDS WILL CONTRIBUTE
TO BLIZZARD CONDITIONS AT TIMES...ESPECIALLY ACROSS EASTERN
SD/SOUTHEAST ND/SOUTHWEST MN TO THE EAST/NORTHEAST OF A DEVELOPING
INVERTED SURFACE TROUGH.
..GUYER.. 02/20/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MPX...FGF...FSD...ABR...BIS...UNR...
LAT...LON 45440348 46180202 46489752 46009324 45059293 44419385
44339762 43510071 44120282 45440348SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 19, 11:25 PM CST | Mesoscale Discussion | SPC | Cottonwood, Faribault, Jackson, Martin, Murray, Nobles and 3 more | 5 hr |
| Feb 20, 4:35 AM CST | Mesoscale Discussion | SPC | Blue Earth, Cottonwood, Dodge, Faribault, Fillmore, Freeborn and 10 more | 6 hr |
| Feb 20, 10:49 AM CST | Mesoscale Discussion | SPC | Dodge, Faribault, Fillmore, Freeborn, Houston, Jackson and 6 more | 4 hr |
| Feb 20, 4:36 AM CST | Mesoscale Discussion | SPC | Aurora, Beadle, Brule, Buffalo, Clark, Codington and 29 more | 4 hr |
Nearby
Mesoscale Discussions in South Dakota, 2011Mesoscale Discussions in Minnesota, 2011Mesoscale Discussions in North Dakota, 2011Every mesoscale discussion in 2011
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.