Alert archive / Nebraska / Mesoscale Discussions in 2011

Mesoscale Discussion 1682

July 21, 201113 counties in Kansas; 23 counties in Nebraska; 7 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2011, 7:10 PM CDT for 13 counties in Kansas; 23 counties in Nebraska; 7 counties in South Dakota. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Jul 21, 2011, 7:10 PM CDT (00:10 UTC)
Expired
Jul 21, 2011, 8:45 PM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 43 counties

Cheyenne County, KS, Decatur County, KS, Gove County, KS, Greeley County, KS, Logan County, KS, Norton County, KS, Rawlins County, KS, Scott County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS, Wichita County, KS, Arthur County, NE, Blaine County, NE, Brown County, NE, Chase County, NE, Cherry County, NE, Custer County, NE, Dawson County, NE, Dundy County, NE, Frontier County, NE, Furnas County, NE, Gosper County, NE, Grant County, NE, Hayes County, NE, Hitchcock County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Perkins County, NE, Red Willow County, NE, Thomas County, NE, Bennett County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 77 km from the middle of the area, began a volume at 00:12 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

Denver, CO (KDNR), launched 00:00Z, 0.2 hours before the alert went out and 250 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-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2011-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2011-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
3380 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
105 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.

IssuedProductOfficeCountiesLasted
Jul 21, 7:47 PM CDTSevere Thunderstorm WatchSPCCheyenne, Decatur, Ellis, Gove, Graham, Greeley and 19 more4 hr
Jul 21, 10:16 PM CDTMesoscale DiscussionSPCAtchison, Brown, Clay, Cloud, Decatur, Dickinson and 37 more89 min
Jul 21, 10:44 PM CDTSevere Thunderstorm WatchSPCAdams, Butler, Cass, Clay, Douglas, Fillmore and 19 more89 min
Jul 22, 6:22 PM CDTMesoscale DiscussionSPCArthur, Blaine, Boyd, Brown, Chase, Cherry and 17 more53 min
Jul 22, 11:05 AM CDTMesoscale DiscussionSPCCorson, Harding, Perkins55 min
Jul 22, 3:00 PM CDTMesoscale DiscussionSPCBeadle, Brookings, Clark, Codington, Day, Deuel and 12 more90 min
Jul 22, 5:17 PM CDTMesoscale DiscussionSPCButte, Harding, Perkins88 min
Jul 22, 5:35 PM CDTTornado WatchSPCCampbell, Corson, Dewey, Edmunds, Harding, McPherson and 3 more8 hr
Jul 22, 5:46 PM CDTMesoscale DiscussionSPCBrown, Campbell, Clark, Codington, Day, Deuel and 10 more89 min
Jul 22, 6:14 PM CDTTornado WatchSPCBrown, Day, Grant, Marshall, Roberts8 hr

Nearby

Mesoscale Discussions in Nebraska, 2011Mesoscale Discussions in Kansas, 2011Mesoscale Discussions in South Dakota, 2011Every 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.