Alert archive / South Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 1504

July 4, 201134 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 4, 2011, 7:59 PM CDT for 34 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 4, 2011, 7:59 PM CDT (00:59 UTC)
Expired
Jul 4, 2011, 10:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 34 counties

Beadle County, SD, Bennett County, SD, Brown County, SD, Brule County, SD, Buffalo County, SD, Campbell County, SD, Clark County, SD, Day County, SD, Dewey County, SD, Edmunds County, SD, Fall River County, SD, Faulk County, SD, Haakon County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jerauld County, SD, Jones County, SD, Lyman County, SD, Marshall County, SD, McPherson County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Potter County, SD, Roberts County, SD, Spink County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Aberdeen radar (KABR), 199 km from the middle of the area, began a volume at 01:02 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 00:00Z, 1.0 hours before the alert went out and 161 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 00:00Z on 2011-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3256 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, Aberdeen, SD at 00:00Z on 2011-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.19395878Sfc1 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
3256 J/kg
Mixed-layer CIN
-52 J/kg
Mixed-layer LCL
1088 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
1.3
Supercell composite
9.4

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 11:14 PM CDTMesoscale DiscussionSPCAurora, Beadle, Bon Homme, Brown, Brule, Buffalo and 32 more91 min
Jul 4, 11:41 PM CDTSevere Thunderstorm WatchSPCAurora, Beadle, Brookings, Brown, Brule, Buffalo and 32 more5 hr
Jul 5, 2:17 PM CDTMesoscale DiscussionSPCBennett, Custer, Fall River, Jackson, Mellette, Oglala Lakota and 1 more73 min
Jul 5, 3:32 PM CDTMesoscale DiscussionSPCClay, Lincoln, Turner, Union88 min

Nearby

Mesoscale Discussions in South Dakota, 2011Every mesoscale discussion in 2011

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.