Alert archive / South Dakota / Mesoscale Discussions in 2012

Mesoscale Discussion 712

May 5, 201216 counties in Minnesota; 19 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 5, 2012, 9:50 AM CDT for 16 counties in Minnesota; 19 counties in South Dakota. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
May 5, 2012, 9:50 AM CDT (14:50 UTC)
Expired
May 5, 2012, 10:45 AM CDT
In force
55 min
Issued by
the Storm Prediction Center
All 35 counties

Brown County, MN, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Renville County, MN, Rock County, MN, Sibley County, MN, Watonwan County, MN, Yellow Medicine County, MN, Aurora County, SD, Beadle County, SD, Brookings County, SD, Brule County, SD, Buffalo County, SD, Davison County, SD, Douglas County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hyde County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD

The radar

The Sioux Falls radar (KFSD), 92 km from the middle of the area, began a volume at 14:53 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 2.8 hours before the alert went out and 106 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-pSkew-T log-p diagram, Aberdeen, SD at 12:00Z on 2012-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 12:00Z on 2012-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
554 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
60 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.

992 
ACUS11 KWNS 051450
SWOMCD
SPC MCD 051450 
MNZ000-IAZ000-SDZ000-051545-

MESOSCALE DISCUSSION 0712
NWS STORM PREDICTION CENTER NORMAN OK
0950 AM CDT SAT MAY 05 2012

AREAS AFFECTED...CNTRL/SERN SD...SWRN MN...NWRN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 247...

VALID 051450Z - 051545Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 247
CONTINUES.

SUMMARY...HAIL REMAINS LIKELY WITH MCS ACTIVITY AS IT SPREADS ACROSS
CNTRL/SERN SD INTO THE UPPER MS VALLEY.  NEW SEVERE THUNDERSTORM
WATCH WILL LIKELY BE REQUIRED INTO PORTIONS OF SRN MN IN THE NEXT
HOUR.

DISCUSSION...TWO MCS CLUSTERS HAVE EVOLVED ACROSS SD THIS MORNING. 
THE LEAD MCS IS SPREADING EWD ACROSS CNTRL PORTIONS OF WW247 AND
EXHIBITS SEVERAL STOUT UPDRAFTS THAT ARE LIKELY PRODUCING VERY LARGE
HAIL OVER MCCOOK AND DAVISON COUNTIES.  THE SECOND MCS WILL SOON
SPREAD INTO THE WRN PARTS OF THE WATCH.  THIS ACTIVITY HAS EVOLVED
WITHIN A ZONE OF FAVORABLE LOW LEVEL WARM ADVECTION AND THE
LIKELIHOOD OF MCS MAINTENANCE IS HIGH GIVEN THAT THE LLJ SHOULD
STRENGTHEN ACROSS SERN SD INTO THE EARLY AFTERNOON HOURS.  WITH TIME
SEVERE ELEVATED STORMS SHOULD PROGRESS INTO SWRN MN...PERHAPS
DEVELOPING INTO THE EXTREME NWRN PARTS OF IA.

..DARROW.. 05/05/2012

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

ATTN...WFO...MPX...DMX...FSD...ABR...UNR...

LAT...LON   44709978 44739402 43499427 43329971 44709978

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 5, 6:49 AM CDTSevere Thunderstorm WatchSPCCottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more7 hr
May 5, 11:38 AM CDTSevere Thunderstorm WatchSPCBlue Earth, Brown, Carver, Dakota, Dodge, Faribault and 20 more6 hr
May 5, 2:58 PM CDTMesoscale DiscussionSPCBlue Earth, Brown, Cottonwood, Dakota, Dodge, Faribault and 20 more62 min
May 5, 6:46 PM CDTSevere Thunderstorm WatchSPCLincoln, Pipestone, Rock6 hr
May 4, 9:54 PM CDTMesoscale DiscussionSPCUnion96 min
May 5, 3:06 AM CDTMesoscale DiscussionSPCCuster, Fall River, Haakon, Hughes, Hyde, Jackson and 9 more84 min
May 5, 3:19 AM CDTSevere Thunderstorm WatchSPCBennett, Buffalo, Butte, Custer, Dewey, Fall River and 17 more9 hr
May 5, 2:09 PM CDTMesoscale DiscussionSPCUnion96 min
May 5, 3:52 PM CDTMesoscale DiscussionSPCClay, Lincoln, Union, Yankton83 min
May 5, 5:31 PM CDTTornado WatchSPCBon Homme, Clay, Union, Yankton5 hr
May 5, 6:21 PM CDTMesoscale DiscussionSPCAurora, Beadle, Bon Homme, Brule, Charles Mix, Davison and 15 more84 min

Nearby

Mesoscale Discussions in South Dakota, 2012Mesoscale Discussions in Minnesota, 2012Every 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.