Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 1046

July 12, 201818 counties in Nebraska; 15 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 12, 2018, 6:36 PM CDT for 18 counties in Nebraska; 15 counties in South Dakota. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jul 12, 2018, 6:36 PM CDT (23:36 UTC)
Expired: Jul 12, 2018, 8:00 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center

All 33 counties

Antelope County, NE, Arthur County, NE, Blaine County, NE, Boyd County, NE, Brown County, NE, Cedar County, NE, Cherry County, NE, Garfield County, NE, Grant County, NE, Holt County, NE, Hooker County, NE, Keya Paha County, NE, Knox County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Rock County, NE, Thomas County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Moody County, SD, Turner County, SD, Yankton County, SD

The radar

The North Platte radar (KLNX), 104 km from the middle of the area, began a volume at 23:40 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 11.6 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: 338 J/kg
Mixed-layer CIN: -214 J/kg
Mixed-layer LCL: 2031 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: -12 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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 12, 2:47 PM CDT	Mesoscale Discussion	SPC	Antelope, Arthur, Blaine, Box Butte, Boyd, Brown and 27 more	2 hr
Jul 12, 3:24 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Boyd, Brown, Cedar, Cherry and 9 more	7 hr
Jul 12, 4:47 PM CDT	Mesoscale Discussion	SPC	Moody	88 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.