Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1882

August 7, 201111 counties in Nebraska; 7 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2011, 12:23 PM MDT for 11 counties in Nebraska; 7 counties in South Dakota. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: Aug 7, 2011, 12:23 PM MDT (18:23 UTC)
Expired: Aug 7, 2011, 1:30 PM MDT
In force: 67 min
Issued by: the Storm Prediction Center

Counties Arthur County, NE, Blaine County, NE, Brown County, NE, Cherry County, NE, Custer County, NE, Grant County, NE, Hooker County, NE, Logan County, NE, McPherson County, NE, Sheridan County, NE, Thomas County, NE, Bennett County, SD, Custer County, SD, Jackson County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Todd County, SD

The radar

The North Platte radar (KLNX), 135 km from the middle of the area, began a volume at 18:23 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 736Aug 7, 2:00 PM MDT

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 6.4 hours before the alert went out and 166 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: 561 J/kg
Mixed-layer CIN: -335 J/kg
Mixed-layer LCL: 1423 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Aug 6, 7:10 PM MDT	Mesoscale Discussion	SPC	Boone, Burt, Butler, Cass, Colfax, Cuming and 23 more	2 hr
Aug 7, 9:48 AM MDT	Mesoscale Discussion	SPC	Nuckolls, Thayer	117 min
Aug 7, 1:58 PM MDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Brown, Buffalo, Cherry, Custer and 21 more	8 hr
Aug 7, 5:35 PM MDT	Mesoscale Discussion	SPC	Adams, Arthur, Blaine, Boyd, Brown, Buffalo and 25 more	115 min

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.