Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1945

August 11, 20119 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2011, 3:15 PM MDT for 9 counties in Nebraska. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: Aug 11, 2011, 3:15 PM MDT (21:15 UTC)
Expired: Aug 11, 2011, 4:15 PM MDT
In force: 60 min
Issued by: the Storm Prediction Center

Counties Arthur County, NE, Cherry County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Logan County, NE, McPherson County, NE, Sheridan County, NE, Thomas County, NE

The radar

The North Platte radar (KLNX), 55 km from the middle of the area, began a volume at 21:18 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.

Tornado Watch 767Aug 11, 3:35 PM MDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 9.3 hours before the alert went out and 128 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: 783 J/kg
Mixed-layer CIN: -249 J/kg
Mixed-layer LCL: 815 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 168 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

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 10, 6:50 PM MDT	Severe Thunderstorm Watch	SPC	Dundy, Hitchcock, Red Willow	3 hr
Aug 10, 9:10 PM MDT	Mesoscale Discussion	SPC	Arthur, Chase, Deuel, Dundy, Frontier, Hayes and 7 more	95 min
Aug 11, 3:38 PM MDT	Tornado Watch	SPC	Blaine, Boyd, Brown, Cherry, Custer, Garfield and 9 more	9 hr
Aug 11, 5:38 PM MDT	Mesoscale Discussion	SPC	Antelope, Boone, Burt, Cedar, Colfax, Cuming and 13 more	97 min

Nearby

Mesoscale Discussions in Nebraska, 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.