Alert archive / South Dakota / Mesoscale Discussions in 2012

Mesoscale Discussion 1095

June 7, 20126 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 7, 2012, 4:27 PM MDT for 6 counties in South Dakota. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Jun 7, 2012, 4:27 PM MDT (22:27 UTC)
Expired
Jun 7, 2012, 5:30 PM MDT
In force
63 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Dewey County, SD, Haakon County, SD, Jackson County, SD, Oglala Lakota County, SD, Stanley County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 87 km from the middle of the area, began a volume at 22:27 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

Rapid City, SD (KUNR), launched 12:00Z, 10.5 hours before the alert went out and 90 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, Rapid City, SD at 12:00Z on 2012-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 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, Rapid City, SD at 12:00Z on 2012-06-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 square meters per square second.193958Sfc1 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
2 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
1016 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
108 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.

373 
ACUS11 KWNS 072228
SWOMCD
SPC MCD 072227
SDZ000-072330-

MESOSCALE DISCUSSION 1095
NWS STORM PREDICTION CENTER NORMAN OK
0527 PM CDT THU JUN 07 2012

AREAS AFFECTED...SWRN AND W-CNTRL SD

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 072227Z - 072330Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLD LARGE HAIL AND STRONG-SEVERE WIND GUSTS WILL REMAIN
POSSIBLE FOR THE NEXT FEW HOURS WITH SCTD TSTM ACTIVITY OVER SWRN
AND W-CNTRL SD.

DISCUSSION...RECENT SURFACE-RADAR MESOANALYSIS PLACES A LOW NEAR PHP
WITH A RAPIDLY SURGING GUST FRONT --EFFECTIVE FRONT-- SITUATED FROM
NEAR THE LOW SWWD INTO FAR SWRN SD.  ALONG AND AHEAD OF THE
BOUNDARY...THE AIRMASS HAS DESTABILIZED AS TEMPS WARMED INTO THE
UPPER 80S AND DEWPOINTS IN THE MID 50S.
DEEP LAYER SHEAR /0-6 KM GENERALLY BELOW 30 KTS/ DECREASES WITH EWD
EXTENT ACROSS THE DISCUSSION AREA AND THIS WILL TEND TO LIMIT
OVERALL STORM ORGANIZATION POTENTIAL.  ALTHOUGH SHORT-TERM
CONVECTIVE-THERMODYNAMIC TRENDS WOULD SUGGEST A BRIEF 1-2 HR PERIOD
FOR SEVERE HAIL/WIND PRIOR TO SUBSTANTIAL CONVECTIVE
OVERTURNING...APPRECIABLE LARGE SCALE FORCING FOR ASCENT VIA A
SHORTWAVE TROUGH --MOVING ACROSS NERN WY/SERN MT/WRN DAKOTAS-- WILL
ACT TO AT LEAST SUPPORT SOME RISK FOR SEVERE INTO THE EARLY EVENING
HOURS.

..SMITH/THOMPSON.. 06/07/2012

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

ATTN...WFO...ABR...UNR...

LAT...LON   43240312 44150273 45130160 45170077 44950047 44060059
            43490118 43230216 43240312

Nearby

Mesoscale Discussions in South Dakota, 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.