Alert archive / South Dakota / Mesoscale Discussions in 2012

Mesoscale Discussion 2111

November 10, 2012Boyd County, Cherry County, Keya Paha County, Nebraska; 26 counties in North Dakota; 41 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Nov 10, 2012, 5:10 PM CST for Boyd County, Cherry County, Keya Paha County, Nebraska; 26 counties in North Dakota; 41 counties in South Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Nov 10, 2012, 5:10 PM CST (23:10 UTC)
Expired: Nov 10, 2012, 9:45 PM CST
In force: 5 hr
Issued by: the Storm Prediction Center

All 70 counties

Barnes County, ND, Benson County, ND, Cass County, ND, Cavalier County, ND, Dickey County, ND, Eddy County, ND, Emmons 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, Pembina County, ND, Ramsey County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Towner County, ND, Traill County, ND, Walsh County, ND, Wells County, ND, Boyd County, NE, Cherry County, NE, Keya Paha County, NE, Aurora County, SD, Beadle County, SD, Bennett County, SD, Brown County, SD, Brule County, SD, Buffalo County, SD, Campbell County, SD, Charles Mix County, SD, Clark County, SD, Codington County, SD, Davison County, SD, Day County, SD, Dewey County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Grant County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jerauld County, SD, Jones County, SD, Kingsbury County, SD, Lyman County, SD, Marshall County, SD, McPherson County, SD, Mellette County, SD, Miner County, SD, Potter County, SD, Roberts County, SD, Sanborn County, SD, Spink County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD

The radar

The Aberdeen radar (KABR), 75 km from the middle of the area, began a volume at 23:12 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, 11.2 hours before the alert went out and 132 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 511 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 256 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

173 
ACUS11 KWNS 102311
SWOMCD
SPC MCD 102310
MNZ000-SDZ000-NDZ000-NEZ000-110345-

MESOSCALE DISCUSSION 2111
NWS STORM PREDICTION CENTER NORMAN OK
0510 PM CST SAT NOV 10 2012

AREAS AFFECTED...FAR NRN NEB...CNTRL AND ERN SD/ND

CONCERNING...HEAVY SNOW

VALID 102310Z - 110345Z

SUMMARY...A BAND OF MODERATE TO HEAVY SNOW EXTENDING N-NEWD FROM
NWRN NEB INTO CNTRL ND WILL SHIFT EWD ACROSS FAR NRN NEB AND THE ERN
DAKOTAS THIS EVENING/TONIGHT. A BRIEF PERIOD OF FREEZING RAIN AND
SLEET MAY OCCUR BEFORE THE ARRIVAL OF THE SNOW BAND...PARTICULARLY
WITH ANY CONVECTIVE ELEMENTS THAT RESIDE ALONG/BEHIND A SURFACE COLD
FRONT.

DISCUSSION...AT 23Z...SURFACE OBSERVATIONS SHOW AN AREA OF LOW
PRESSURE LOCATED OVER FAR NERN SD AND W-CNTRL MN...WITH A COLD FRONT
EXTENDING SWWD INTO CNTRL NEB. INCREASING LARGE-SCALE ASCENT
ASSOCIATED WITH A SHORTWAVE TROUGH OVER THE CNTRL HIGH PLAINS IS
AIDING IN THE DEVELOPMENT OF THUNDERSTORMS ALONG THE FRONT OVER
NEB...WHILE LOW AND MIDLEVEL FRONTOGENESIS IS FOCUSING A BAND OF
MODERATE TO HEAVY SNOW BEHIND THE FRONT FROM NWRN NEB INTO CNTRL ND.
AS THE EVENING/NIGHT PROGRESSES...THE COLD FRONT/FRONTOGENETIC ZONE
WILL CONTINUE TO SHIFT EWD ACROSS NRN NEB AND THE ERN DAKOTAS. THE
PLUME OF LARGE-SCALE ASCENT COMBINED WITH THE FRONTAL CIRCULATION
WILL AID IN SNOWFALL RATES NEAR 1 IN/HR. IN ADDITION...A BRIEF
PERIOD OF FREEZING RAIN OR SLEET MAY OCCUR NEAR THE
FRONT...PARTICULARLY WITH ANY CONVECTIVE ELEMENTS THAT LIFT NEWD
ACROSS THE AREA.

..GARNER.. 11/10/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FGF...FSD...OAX...ABR...BIS...LBF...UNR...

LAT...LON   49049762 48189697 45369666 42789816 42180079 42750223
            45910081 48989949 49049762

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 10, 12:11 PM CST	Mesoscale Discussion	SPC	Dawes, Sioux	4 hr
Nov 10, 1:53 PM CST	Mesoscale Discussion	SPC	Adams, Burt, Butler, Clay, Colfax, Cuming and 22 more	2 hr
Nov 10, 3:36 PM CST	Severe Thunderstorm Watch	SPC	Adams, Burt, Butler, Cass, Clay, Colfax and 28 more	7 hr
Nov 9, 6:17 PM CST	Mesoscale Discussion	SPC	Adams, Benson, Billings, Bottineau, Bowman, Burke and 21 more	4 hr

Nearby

Mesoscale Discussions in South Dakota, 2012 Mesoscale Discussions in North Dakota, 2012 Mesoscale Discussions in Nebraska, 2012 Every mesoscale discussion in 2012

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.