Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 927

June 28, 20186 counties in Nebraska; 5 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2018, 5:10 PM MDT for 6 counties in Nebraska; 5 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 28, 2018, 5:10 PM MDT (23:10 UTC)
Expired: Jun 28, 2018, 7:15 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Arthur County, NE, Cherry County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Sheridan County, NE, Bennett County, SD, Jackson County, SD, Mellette County, SD, Oglala Lakota County, SD, Todd County, SD

The radar

The North Platte radar (KLNX), 128 km from the middle of the area, began a volume at 23:13 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 (KRAP), launched 12:00Z, 11.2 hours before the alert went out and 180 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: 2626 J/kg
Mixed-layer CIN: -339 J/kg
Mixed-layer LCL: 1551 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 223 m²/s²
0-3 km storm-relative helicity: 234 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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
Jun 28, 6:20 AM MDT	Mesoscale Discussion	SPC	Antelope, Boone, Burt, Butler, Cass, Colfax and 26 more	2 hr
Jun 28, 7:12 AM MDT	Severe Thunderstorm Watch	SPC	Burt, Butler, Cass, Colfax, Cuming, Dodge and 7 more	6 hr
Jun 28, 6:40 AM MDT	Mesoscale Discussion	SPC	Campbell, Corson, McPherson	3 hr
Jun 28, 3:42 PM MDT	Tornado Watch	SPC	Harding, Perkins	7 hr
Jun 28, 5:59 PM MDT	Mesoscale Discussion	SPC	Corson, Harding, Perkins	91 min

Nearby

Mesoscale Discussions in Nebraska, 2018 Mesoscale Discussions in South Dakota, 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.