Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1698

July 22, 201123 counties in Nebraska; 7 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 22, 2011, 5:22 PM MDT for 23 counties in Nebraska; 7 counties in South Dakota. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: Jul 22, 2011, 5:22 PM MDT (23:22 UTC)
Expired: Jul 22, 2011, 6:15 PM MDT
In force: 53 min
Issued by: the Storm Prediction Center

All 30 counties

Arthur County, NE, Blaine County, NE, Boyd County, NE, Brown County, NE, Chase County, NE, Cherry County, NE, Custer County, NE, Dawson County, NE, Frontier County, NE, Gosper County, NE, Hayes County, NE, Hitchcock County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Perkins County, NE, Red Willow County, NE, Rock County, NE, Thomas County, NE, Brule County, SD, Buffalo County, SD, Gregory County, SD, Lyman County, SD, Mellette County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 39 km from the middle of the area, began a volume at 23:24 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, 11.4 hours before the alert went out and 127 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: 121 J/kg
Mixed-layer CIN: -417 J/kg
Mixed-layer LCL: 1740 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 6:10 PM MDT	Mesoscale Discussion	SPC	Arthur, Blaine, Brown, Chase, Cherry, Custer and 17 more	95 min
Jul 21, 6:47 PM MDT	Severe Thunderstorm Watch	SPC	Dundy, Franklin, Furnas, Harlan, Hitchcock, Nuckolls and 2 more	4 hr
Jul 21, 9:16 PM MDT	Mesoscale Discussion	SPC	Adams, Clay, Fillmore, Franklin, Furnas, Gage and 13 more	89 min
Jul 21, 9:44 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Butler, Cass, Clay, Douglas, Fillmore and 19 more	89 min
Jul 22, 10:05 AM MDT	Mesoscale Discussion	SPC	Corson, Harding, Perkins	55 min
Jul 22, 2:00 PM MDT	Mesoscale Discussion	SPC	Beadle, Brookings, Clark, Codington, Day, Deuel and 12 more	90 min
Jul 22, 4:17 PM MDT	Mesoscale Discussion	SPC	Butte, Harding, Perkins	88 min
Jul 22, 4:35 PM MDT	Tornado Watch	SPC	Campbell, Corson, Dewey, Edmunds, Harding, McPherson and 3 more	8 hr
Jul 22, 4:46 PM MDT	Mesoscale Discussion	SPC	Brown, Campbell, Clark, Codington, Day, Deuel and 10 more	89 min
Jul 22, 5:14 PM MDT	Tornado Watch	SPC	Brown, Day, Grant, Marshall, Roberts	8 hr

Nearby

Mesoscale Discussions in Nebraska, 2011 Mesoscale Discussions in South Dakota, 2011 Every mesoscale discussion in 2011

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.