Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1754

July 26, 20114 counties in Colorado; 10 counties in Nebraska; Mellette County, Todd County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2011, 4:06 PM MDT for 4 counties in Colorado; 10 counties in Nebraska; Mellette County, Todd County, South Dakota. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jul 26, 2011, 4:06 PM MDT (22:06 UTC)
Expired: Jul 26, 2011, 5:30 PM MDT
In force: 84 min
Issued by: the Storm Prediction Center

Counties Kit Carson County, CO, Phillips County, CO, Sedgwick County, CO, Yuma County, CO, Arthur County, NE, Chase County, NE, Cherry County, NE, Deuel County, NE, Dundy County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Perkins County, NE, Mellette County, SD, Todd County, SD

The radar

The North Platte radar (KLNX), 120 km from the middle of the area, began a volume at 22:08 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 690Jul 26, 4:45 PM MDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 10.1 hours before the alert went out and 109 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: 1007 J/kg
Mixed-layer CIN: -230 J/kg
Mixed-layer LCL: 982 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 206 m²/s²
0-3 km storm-relative helicity: 311 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 7.6

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
Jul 26, 4:43 PM MDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Boyd, Brown, Chase, Cherry and 19 more	7 hr
Jul 25, 8:33 PM MDT	Mesoscale Discussion	SPC	Beadle, Brookings, Buffalo, Hamlin, Hand, Hughes and 9 more	57 min
Jul 26, 9:45 AM MDT	Mesoscale Discussion	SPC	Campbell, Edmunds, Faulk, Hand, McPherson	60 min
Jul 26, 2:59 PM MDT	Mesoscale Discussion	SPC	Aurora, Beadle, Brown, Brule, Buffalo, Campbell and 27 more	2 hr
Jul 26, 4:21 PM MDT	Tornado Watch	SPC	Brown, Buffalo, Campbell, Corson, Dewey, Edmunds and 12 more	5 hr

Nearby

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