Alert archive / Nebraska / Mesoscale Discussions in 2021

Mesoscale Discussion 1604

August 26, 202112 counties in Nebraska; 6 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 26, 2021, 3:10 AM CDT for 12 counties in Nebraska; 6 counties in South Dakota. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Aug 26, 2021, 3:10 AM CDT (08:10 UTC)
Expired: Aug 26, 2021, 5:45 AM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

Counties Antelope County, NE, Boyd County, NE, Cedar County, NE, Dixon County, NE, Garfield County, NE, Holt County, NE, Knox County, NE, Loup County, NE, Pierce County, NE, Rock County, NE, Wayne County, NE, Wheeler County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Hutchinson County, SD, Turner County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 175 km from the middle of the area, began a volume at 08:10 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

Omaha, NE (KOAX), launched 00:00Z, 8.2 hours before the alert went out and 208 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: 1609 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 1502 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: -22 m²/s²
0-3 km storm-relative helicity: 66 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.7

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
Aug 26, 5:34 PM CDT	Mesoscale Discussion	SPC	Antelope, Boone, Burt, Butler, Cedar, Colfax and 24 more	116 min
Aug 26, 2:35 AM CDT	Mesoscale Discussion	SPC	Brown, Campbell, Corson, Dewey, Edmunds, Faulk and 6 more	2 hr
Aug 26, 8:36 AM CDT	Mesoscale Discussion	SPC	Beadle, Brookings, Buffalo, Clark, Codington, Day and 10 more	84 min
Aug 26, 9:05 AM CDT	Severe Thunderstorm Watch	SPC	Beadle, Brookings, Clark, Codington, Deuel, Grant and 7 more	4 hr
Aug 26, 10:43 AM CDT	Mesoscale Discussion	SPC	Brookings, Deuel, Moody	92 min

Nearby

Mesoscale Discussions in Nebraska, 2021 Mesoscale Discussions in South Dakota, 2021 Every mesoscale discussion in 2021

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.