Alert archive / Nebraska / Mesoscale Discussions in 2017

Mesoscale Discussion 1166

June 27, 201733 counties in Nebraska; 7 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 27, 2017, 8:12 PM CDT for 33 counties in Nebraska; 7 counties in South Dakota. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: Jun 27, 2017, 8:12 PM CDT (01:12 UTC)
Expired: Jun 27, 2017, 9:45 PM CDT
In force: 93 min
Issued by: the Storm Prediction Center

All 40 counties

Antelope County, NE, Blaine County, NE, Boone County, NE, Boyd County, NE, Brown County, NE, Buffalo County, NE, Butler County, NE, Cherry County, NE, Custer County, NE, Dawson County, NE, Garfield County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Holt County, NE, Hooker County, NE, Howard County, NE, Keith County, NE, Keya Paha County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Merrick County, NE, Nance County, NE, Platte County, NE, Polk County, NE, Rock County, NE, Sherman County, NE, Thomas County, NE, Valley County, NE, Wheeler County, NE, York County, NE, Gregory County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 44 km from the middle of the area, began a volume at 01:14 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 374Jun 27, 9:00 PM CDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 1.2 hours before the alert went out and 130 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: 2312 J/kg
Mixed-layer CIN: -122 J/kg
Mixed-layer LCL: 2154 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 108 m²/s²
0-3 km storm-relative helicity: 303 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 12.3

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 27, 7:35 PM CDT	Severe Thunderstorm Watch	SPC	Dakota, Dixon	5 hr
Jun 27, 8:56 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Antelope, Boone, Boyd, Buffalo, Butler and 37 more	5 hr
Jun 27, 11:33 PM CDT	Mesoscale Discussion	SPC	Burt, Cass, Dodge, Douglas, Lancaster, Otoe and 4 more	57 min
Jun 28, 2:14 PM CDT	Mesoscale Discussion	SPC	Otoe	2 hr
Jun 28, 2:53 PM CDT	Tornado Watch	SPC	Cass, Douglas, Nemaha, Otoe, Richardson, Sarpy	9 hr
Jun 28, 4:07 PM CDT	Mesoscale Discussion	SPC	Banner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 5 more	113 min
Jun 28, 5:29 PM CDT	Mesoscale Discussion	SPC	Nemaha	91 min
Jun 28, 5:46 PM CDT	Mesoscale Discussion	SPC	Gage, Jefferson, Johnson, Pawnee, Richardson, Thayer	89 min
Jun 27, 7:02 PM CDT	Mesoscale Discussion	SPC	Aurora, Beadle, Brule, Buffalo, Charles Mix, Davison and 18 more	88 min
Jun 28, 3:28 PM CDT	Mesoscale Discussion	SPC	Butte, Custer, Fall River, Lawrence, Oglala Lakota, Pennington	2 hr

Nearby

Mesoscale Discussions in Nebraska, 2017 Mesoscale Discussions in South Dakota, 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.