Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 506

May 23, 201816 counties in Nebraska; 11 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 23, 2018, 7:28 PM MDT for 16 counties in Nebraska; 11 counties in South Dakota. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: May 23, 2018, 7:28 PM MDT (01:28 UTC)
Expired: May 23, 2018, 9:00 PM MDT
In force: 92 min
Issued by: the Storm Prediction Center

All 27 counties

Arthur County, NE, Box Butte County, NE, Brown County, NE, Cherry County, NE, Cheyenne County, NE, Dawes County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keya Paha County, NE, McPherson County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Thomas County, NE, Bennett County, SD, Fall River County, SD, Haakon County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Oglala Lakota County, SD, Stanley County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 146 km from the middle of the area, began a volume at 01:28 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 00:00Z, 1.5 hours before the alert went out and 163 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: 255 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 2269 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 82 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
May 24, 1:36 PM MDT	Mesoscale Discussion	SPC	Boyd	2 hr

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.