Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1578

July 11, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Jul 11, 2011, 1:50 PM MDT for 4 states. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Jul 11, 2011, 1:50 PM MDT (19:50 UTC)
Expired: Jul 11, 2011, 3:15 PM MDT
In force: 85 min
Issued by: the Storm Prediction Center

All 32 counties

Carter County, MT, Fallon County, MT, Powder River County, MT, Arthur County, NE, Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Keith County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Butte County, SD, Custer County, SD, Fall River County, SD, Harding County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Campbell County, WY, Converse County, WY, Crook County, WY, Goshen County, WY, Niobrara County, WY, Platte County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 55 km from the middle of the area, began a volume at 19:53 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.

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 7.8 hours before the alert went out and 48 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1860 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: -49 m²/s²
0-3 km storm-relative helicity: 74 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
Jul 11, 2:53 PM MDT	Mesoscale Discussion	SPC	Beaverhead, Broadwater, Deer Lodge, Gallatin, Jefferson, Madison and 4 more	97 min
Jul 10, 6:21 PM MDT	Mesoscale Discussion	SPC	Adams, Blaine, Brown, Buffalo, Chase, Custer and 29 more	84 min
Jul 10, 6:24 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Blaine, Boyd, Brown, Buffalo, Chase and 38 more	6 hr
Jul 10, 9:27 PM MDT	Mesoscale Discussion	SPC	Antelope, Boone, Buffalo, Burt, Butler, Cedar and 27 more	63 min
Jul 10, 9:57 PM MDT	Severe Thunderstorm Watch	SPC	Antelope, Boone, Burt, Butler, Cedar, Colfax and 14 more	4 hr
Jul 10, 10:56 PM MDT	Severe Thunderstorm Watch	SPC	Dakota, Dixon	4 hr
Jul 11, 2:07 PM MDT	Severe Thunderstorm Watch	SPC	Banner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 5 more	7 hr
Jul 11, 4:01 PM MDT	Mesoscale Discussion	SPC	Cherry, Dawes, Sheridan	29 min
Jul 11, 4:06 PM MDT	Tornado Watch	SPC	Box Butte, Cherry, Dawes, Sheridan, Sioux	5 hr

Nearby

Mesoscale Discussions in Nebraska, 2011 Mesoscale Discussions in South Dakota, 2011 Mesoscale Discussions in Wyoming, 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.