Alert archive / South Dakota / Mesoscale Discussions in 2018

Mesoscale Discussion 1479

September 19, 2018Big Stone County, Lac qui Parle County, Lincoln County, Minnesota; 18 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Sep 19, 2018, 3:47 AM CDT for Big Stone County, Lac qui Parle County, Lincoln County, Minnesota; 18 counties in South Dakota. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Sep 19, 2018, 3:47 AM CDT (08:47 UTC)
Expired: Sep 19, 2018, 6:45 AM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 5%

All 21 counties

Big Stone County, MN, Lac qui Parle County, MN, Lincoln County, MN, Beadle County, SD, Brookings County, SD, Clark County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Dewey County, SD, Edmunds County, SD, Faulk County, SD, Grant County, SD, Hamlin County, SD, Hand County, SD, Hyde County, SD, Kingsbury County, SD, Potter County, SD, Spink County, SD, Sully County, SD, Walworth County, SD

The radar

The Aberdeen radar (KABR), 62 km from the middle of the area, began a volume at 08:49 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

Bismarck Municip, ND (KBIS), launched 00:00Z, 8.8 hours before the alert went out and 280 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: 1699 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: -54 m²/s²
0-3 km storm-relative helicity: 158 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 19, 2:40 AM CDT	Mesoscale Discussion	SPC	Cottonwood, Jackson, Martin, Murray, Nobles, Pipestone and 2 more	3 hr

Nearby

Mesoscale Discussions in South Dakota, 2018 Mesoscale Discussions in Minnesota, 2018 Every mesoscale discussion in 2018

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.