Alert archive / Nebraska / Mesoscale Discussions in 2007

Mesoscale Discussion 1248

June 21, 200727 counties in Nebraska; 4 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 21, 2007, 9:45 PM CDT for 27 counties in Nebraska; 4 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 21, 2007, 9:45 PM CDT (02:45 UTC)
Expired: Jun 21, 2007, 11:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 31 counties

Antelope County, NE, Boone County, NE, Boyd County, NE, Burt County, NE, Butler County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Garfield County, NE, Greeley County, NE, Holt County, NE, Knox County, NE, Loup County, NE, Madison County, NE, Nance County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Rock County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE, Bon Homme County, SD, Clay County, SD, Union County, SD, Yankton County, SD

The radar

The Omaha radar (KOAX), 178 km from the middle of the area, began a volume at 02:45 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 nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 2.8 hours before the alert went out and 235 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: 3305 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 1841 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: 126 m²/s²
0-3 km storm-relative helicity: 332 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
Jun 21, 7:15 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Buffalo, Clay, Dawson, Fillmore, Franklin and 19 more	6 hr
Jun 22, 2:21 PM CDT	Mesoscale Discussion	SPC	Adams, Boone, Burt, Butler, Cass, Clay and 36 more	114 min
Jun 22, 2:56 PM CDT	Severe Thunderstorm Watch	SPC	Burt, Butler, Cass, Clay, Colfax, Dodge and 13 more	6 hr
Jun 22, 3:00 PM CDT	Mesoscale Discussion	SPC	Banner, Chase, Cheyenne, Deuel, Dundy, Kimball	3 hr

Nearby

Mesoscale Discussions in Nebraska, 2007 Mesoscale Discussions in South Dakota, 2007 Every mesoscale discussion in 2007

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.