Alert archive / South Dakota / Mesoscale Discussions in 2012

Mesoscale Discussion 1176

June 15, 2012Cherry County, Sheridan County, Nebraska; 13 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 15, 2012, 3:59 PM MDT for Cherry County, Sheridan County, Nebraska; 13 counties in South Dakota. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: Jun 15, 2012, 3:59 PM MDT (21:59 UTC)
Expired: Jun 15, 2012, 5:30 PM MDT
In force: 91 min
Issued by: the Storm Prediction Center

Counties Cherry County, NE, Sheridan County, NE, Bennett County, SD, Haakon County, SD, Hughes County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD

The radar

The Rapid City radar (KUDX), 137 km from the middle of the area, began a volume at 22:01 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.

Severe Thunderstorm Watch 397Jun 15, 4:15 PM MDT

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 10.0 hours before the alert went out and 138 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: 1967 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 277 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

776 
ACUS11 KWNS 152200
SWOMCD
SPC MCD 152159
SDZ000-NEZ000-152330-

MESOSCALE DISCUSSION 1176
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT FRI JUN 15 2012

AREAS AFFECTED...NCNTRL NEB AND CNTRL SD

CONCERNING...SEVERE THUNDERSTORM WATCH 395...

VALID 152159Z - 152330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 395
CONTINUES.

SUMMARY...A SEVERE THREAT WILL MOVE GRADUALLY ENEWD ACROSS NRN NEB
AND INTO CNTRL SD EARLY THIS EVENING. LARGE HAIL AND ISOLATED WIND
DAMAGE WILL BE THE PRIMARY THREATS AND WW ISSUANCE WILL BE NEEDED TO
THE EAST OF WW 395.

DISCUSSION...A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS IS ONGOING
JUST SOUTH OF THE RAPID CITY AREA IN A POCKET OF MODERATE
INSTABILITY WHERE MLCAPE IS ESTIMATED IN THE 1000 TO 2000 J/KG
RANGE. IN ADDITION TO THE INSTABILITY...THE WSR-88D VWP AT RAPID
CITY SHOWS STRONG DIRECTIONAL SHEAR BELOW 3 KM WITH 40 KT IN THE
MID-LEVELS. THE STRONG VERTICAL SHEAR WILL BE FAVORABLE FOR SEVERE
STORMS AND A SUPERCELL OR TWO MAY DEVELOP AS STORMS MOVE NEWD EARLY
THIS EVENING. STEEP MID-LEVEL LAPSE RATES WILL BE SUFFICIENT FOR
LARGE HAIL. LAPSE RATES ARE ALSO VERY STEEP AT LOW-LEVELS WITH 0-3
KM LAPSE RATES ESTIMATED ABOVE 9.0 C/KM ACROSS MUCH OF CNTRL SD.
THIS MAY HELP THE WIND DAMAGE TO INCREASE EARLY THIS EVENING.

..BROYLES/CARBIN.. 06/15/2012

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

ATTN...WFO...FSD...ABR...LBF...UNR...CYS...

LAT...LON   44650257 43630307 43010302 42480238 42360159 42490083
            43009990 43429951 43959933 44929958 45090083 44650257

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 15, 12:54 PM MDT	Mesoscale Discussion	SPC	Banner, Box Butte, Cheyenne, Dawes, Deuel, Kimball and 3 more	96 min
Jun 15, 1:35 PM MDT	Severe Thunderstorm Watch	SPC	Banner, Box Butte, Cheyenne, Dawes, Kimball, Morrill and 2 more	7 hr
Jun 15, 4:14 PM MDT	Severe Thunderstorm Watch	SPC	Brown, Cherry, Keya Paha, Sheridan	6 hr

Nearby

Mesoscale Discussions in South 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.