Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1916

August 9, 2011Logan County, Phillips County, Sedgwick County, Colorado; 9 counties in Nebraska; Goshen County, Platte County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Aug 9, 2011, 12:47 PM MDT for Logan County, Phillips County, Sedgwick County, Colorado; 9 counties in Nebraska; Goshen County, Platte County, Wyoming. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: Aug 9, 2011, 12:47 PM MDT (18:47 UTC)
Expired: Aug 9, 2011, 2:45 PM MDT
In force: 118 min
Issued by: the Storm Prediction Center

Counties Logan County, CO, Phillips County, CO, Sedgwick County, CO, Banner County, NE, Chase County, NE, Cheyenne County, NE, Deuel County, NE, Dundy County, NE, Kimball County, NE, Morrill County, NE, Perkins County, NE, Scotts Bluff County, NE, Goshen County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 143 km from the middle of the area, began a volume at 18:51 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 754Aug 9, 1:55 PM MDT

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 6.8 hours before the alert went out and 142 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: 245 J/kg
Mixed-layer CIN: -295 J/kg
Mixed-layer LCL: 1813 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 91 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 9, 1:51 PM MDT	Tornado Watch	SPC	Logan, Morgan, Phillips, Sedgwick, Washington, Weld and 1 more	7 hr
Aug 9, 5:02 PM MDT	Mesoscale Discussion	SPC	Logan, Morgan, Phillips, Sedgwick, Washington, Weld and 1 more	118 min
Aug 9, 9:25 AM MDT	Mesoscale Discussion	SPC	Arthur, Box Butte, Cherry, Dawes, Garden, Grant and 6 more	95 min

Nearby

Mesoscale Discussions in Nebraska, 2011 Mesoscale Discussions in Colorado, 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.