Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 1071

July 17, 20185 counties in Nebraska; Bennett County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 17, 2018, 10:04 PM MDT for 5 counties in Nebraska; Bennett County, South Dakota. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Jul 17, 2018, 10:04 PM MDT (04:04 UTC)
Expired: Jul 17, 2018, 11:30 PM MDT
In force: 86 min
Issued by: the Storm Prediction Center

Counties Box Butte County, NE, Dawes County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Bennett County, SD

The radar

The Rapid City radar (KUDX), 163 km from the middle of the area, began a volume at 04:03 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, 4.1 hours before the alert went out and 157 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: 680 J/kg
Mixed-layer CIN: -83 J/kg
Mixed-layer LCL: 1476 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 75 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

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, 12:57 AM MDT	Mesoscale Discussion	SPC	Arthur, Garden, Grant, Hooker, Keith, McPherson and 2 more	2 hr
Jul 18, 12:39 PM MDT	Mesoscale Discussion	SPC	Boyd, Brown, Holt, Keya Paha, Rock	2 hr
Jul 18, 2:43 PM MDT	Tornado Watch	SPC	Antelope, Boyd, Brown, Cedar, Garfield, Holt and 5 more	7 hr
Jul 18, 3:59 PM MDT	Mesoscale Discussion	SPC	Blaine, Brown, Buffalo, Cherry, Custer, Dawson and 15 more	91 min
Jul 18, 4:16 PM MDT	Mesoscale Discussion	SPC	Antelope, Boyd, Cedar, Dixon, Holt, Keya Paha and 5 more	119 min
Jul 18, 5:14 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Antelope, Blaine, Boone, Boyd, Brown and 52 more	7 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.