Alert archive / South Dakota / Mesoscale Discussions in 2017

Mesoscale Discussion 1353

July 19, 2017Boyd County, Nebraska; 5 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 19, 2017, 2:52 PM CDT for Boyd County, Nebraska; 5 counties in South Dakota. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Jul 19, 2017, 2:52 PM CDT (19:52 UTC)
Expired: Jul 19, 2017, 4:15 PM CDT
In force: 83 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Boyd County, NE, Charles Mix County, SD, Douglas County, SD, Gregory County, SD, Mellette County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 175 km from the middle of the area, began a volume at 19:54 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 422Jul 19, 4:50 PM CDT

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 7.9 hours before the alert went out and 196 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: 1451 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 91 m²/s²
0-3 km storm-relative helicity: 208 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
Jul 18, 7:58 PM CDT	Mesoscale Discussion	SPC	Box Butte, Dawes, Sheridan, Sioux	2 hr
Jul 19, 4:52 PM CDT	Severe Thunderstorm Watch	SPC	Antelope, Boyd, Brown, Cedar, Cherry, Dakota and 8 more	6 hr
Jul 19, 7:01 AM CDT	Mesoscale Discussion	SPC	Brown, Campbell, Corson, Day, Dewey, Edmunds and 13 more	119 min
Jul 19, 9:55 AM CDT	Mesoscale Discussion	SPC	Beadle, Brookings, Clark, Codington, Day, Deuel and 6 more	2 hr
Jul 19, 10:24 AM CDT	Severe Thunderstorm Watch	SPC	Aurora, Beadle, Brookings, Clark, Codington, Davison and 15 more	4 hr
Jul 19, 12:11 PM CDT	Mesoscale Discussion	SPC	Lake, Lincoln, McCook, Minnehaha, Moody, Turner	2 hr

Nearby

Mesoscale Discussions in South Dakota, 2017 Mesoscale Discussions in Nebraska, 2017 Every mesoscale discussion in 2017

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.