Alert archive / South Dakota / Mesoscale Discussions in 2015

Mesoscale Discussion 1513

July 23, 2015Lake County, Miner County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 23, 2015, 10:17 PM CDT for Lake County, Miner County, South Dakota. It was in force for 28 min.

The area

The outline as issued.

The facts

Issued: Jul 23, 2015, 10:17 PM CDT (03:17 UTC)
Expired: Jul 23, 2015, 10:45 PM CDT
In force: 28 min
Issued by: the Storm Prediction Center
Chance of a watch: 5%

Counties Lake County, SD, Miner County, SD

The radar

The Sioux Falls radar (KFSD), 77 km from the middle of the area, began a volume at 03:17 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, 3.3 hours before the alert went out and 122 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: 3528 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1264 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 129 m²/s²
0-3 km storm-relative helicity: 209 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 12.1

Open this sounding in Storm Lab

The text

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

084 
ACUS11 KWNS 240317
SWOMCD
SPC MCD 240317 
SDZ000-240345-

MESOSCALE DISCUSSION 1513
NWS STORM PREDICTION CENTER NORMAN OK
1017 PM CDT THU JUL 23 2015

AREAS AFFECTED...A SMALL PART OF ERN SD

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 240317Z - 240345Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...A SUPERCELL IN MINER COUNTY WILL POSE THE RISK FOR ALL SVR
HAZARDS AS IT TRACKS EWD/ESEWD IN THE SHORT-TERM. SUCH POTENTIAL
WILL REMAIN TOO ISOLATED AND SHORT-DURATION FOR WW ISSUANCE.

DISCUSSION...A SUPERCELL IS MOVING EWD/ESEWD ACROSS MINER COUNTY IN
A STRONGLY UNSTABLE ENVIRONMENT. HIGH THETA-E IN THE BOUNDARY LAYER
CHARACTERIZED BY SFC DEWPOINTS IN THE LOWER/MIDDLE 70S HAS ALLOWED
MLCINH TO BE SLOW TO INCREASE...WHILE THE FSD VWP HAS INDICATED A
STRONG INCREASE IN LOW-LEVEL SRH DURING THE PAST FEW HOURS IN
ASSOCIATION WITH THE NOCTURNAL BOUNDARY-LAYER WIND MAX. THE
SUPERCELL CONTINUES TO SUPPORT POTENTIAL FOR ALL SEVERE HAZARDS
/WIND...HAIL...AND TORNADO/...AND RADAR DATA SUGGEST MODERATE-STRONG
LOW-LEVEL ROTATION ASSOCIATED WITH THIS STORM. THIS STORM WILL
LIKELY POSE SIMILAR RISKS IN THE NEXT HOUR OR SO BEFORE IT ADVANCES
INTO COOLER AIR WITH RELATED INHIBITION ENHANCED BY DIABATIC SFC
COOLING.

..COHEN/HART.. 07/24/2015

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

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

LAT...LON   44049782 44209744 44129698 43909710 43899742 43959772
            44049782

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 23, 10:28 PM CDT	Mesoscale Discussion	SPC	Brown, Day, Marshall, Roberts	32 min
Jul 24, 12:41 AM CDT	Mesoscale Discussion	SPC	Brown, Day, Marshall, Roberts	2 hr
Jul 24, 2:23 AM CDT	Mesoscale Discussion	SPC	Deuel, Grant	67 min

Nearby

Mesoscale Discussions in South Dakota, 2015 Every mesoscale discussion in 2015

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.