Alert archive / South Dakota / Mesoscale Discussions in 2012

Mesoscale Discussion 1285

June 25, 201210 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2012, 11:38 PM CDT for 10 counties in South Dakota. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: Jun 25, 2012, 11:38 PM CDT (04:38 UTC)
Expired: Jun 26, 2012, 12:45 AM CDT
In force: 67 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Beadle County, SD, Brown County, SD, Clark County, SD, Edmunds County, SD, Faulk County, SD, Hand County, SD, Hyde County, SD, Potter County, SD, Spink County, SD, Walworth County, SD

The radar

The Aberdeen radar (KABR), 52 km from the middle of the area, began a volume at 04:41 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 00:00Z, 4.6 hours before the alert went out and 47 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: 1647 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 220 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.

581 
ACUS11 KWNS 260438
SWOMCD
SPC MCD 260438 
SDZ000-260545-

MESOSCALE DISCUSSION 1285
NWS STORM PREDICTION CENTER NORMAN OK
1138 PM CDT MON JUN 25 2012

AREAS AFFECTED...CNTRL AND NERN SD

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 260438Z - 260545Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED OCCURRENCES SEVERE HAIL WILL BE POSSIBLE WITH
ELEVATED TSTMS.  A WW IS NOT ANTICIPATED.

DISCUSSION...A BAND OF TSTMS HAS RECENTLY DEVELOPED OVER PARTS OF
POTTER...SULLY...HYDE...AND HAND COUNTIES IN CNTRL SD ALONG ERN
FRINGE OF DECAYING MCS MOVING TOWARD THE MO RIVER.  THIS ACTIVITY IS
LIKELY ELEVATED ABOVE A PRONOUNCED CAP AND FORCED BY A COMBINATION
OF UPLIFT ALONG COLD POOL ATTENDANT TO DECAYING MCS...AND INCREASING
ISENTROPIC ASCENT ALONG STRENGTHENING NOCTURNAL LOW-LEVEL WIND
MAXIMUM.  THE PRESENCE OF STEEP MIDLEVEL LAPSE RATES WILL SUPPORT
VIGOROUS UPDRAFT GROWTH WITH A RISK FOR ISOLATED OCCURRENCES OF
SEVERE HAIL.  A MORE ROBUST SEVERE WEATHER THREAT WILL LIKELY BE
MODULATED BY WEAK CLOUD-BEARING SHEAR AND A GRADUAL PROGRESSION OF
STORMS AWAY FROM LOW-LEVEL INSTABILITY AXIS.

..MEAD.. 06/26/2012

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

ATTN...WFO...FSD...ABR...

LAT...LON   44920016 45450030 45729994 45759918 45789844 45689801
            45339766 44869761 44539781 44379836 44299909 44920016

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 25, 8:37 PM CDT	Mesoscale Discussion	SPC	Bennett, Corson, Dewey, Haakon, Hughes, Jackson and 11 more	83 min
Jun 26, 3:06 PM CDT	Mesoscale Discussion	SPC	Butte, Corson, Harding, Meade, Pennington, Perkins and 1 more	54 min

Nearby

Mesoscale Discussions in South Dakota, 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.