Alert archive / Nebraska / Mesoscale Discussions in 2009

Mesoscale Discussion 1809

August 7, 200937 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2009, 1:23 AM CDT for 37 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 7, 2009, 1:23 AM CDT (06:23 UTC)
Expired: Aug 7, 2009, 3:30 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 37 counties

Adams County, NE, Antelope County, NE, Boone County, NE, Buffalo County, NE, Butler County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dawson County, NE, Fillmore County, NE, Garfield County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Holt County, NE, Howard County, NE, Kearney County, NE, Knox County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Phelps County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Rock County, NE, Saline County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Stanton County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE, York County, NE

The radar

The North Platte radar (KLNX), 133 km from the middle of the area, began a volume at 06:23 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, 6.4 hours before the alert went out and 140 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: 1404 J/kg
Mixed-layer CIN: -193 J/kg
Mixed-layer LCL: 1264 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 232 m²/s²
0-3 km storm-relative helicity: 266 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 8.1

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 6, 8:34 PM CDT	Mesoscale Discussion	SPC	Arthur, Box Butte, Cherry, Cheyenne, Dawes, Deuel and 4 more	86 min
Aug 6, 9:15 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Brown, Buffalo, Chase, Cherry and 20 more	6 hr
Aug 7, 3:55 PM CDT	Mesoscale Discussion	SPC	Adams, Antelope, Boone, Buffalo, Burt, Butler and 35 more	95 min
Aug 7, 6:37 PM CDT	Mesoscale Discussion	SPC	Arthur, Banner, Box Butte, Cheyenne, Dawes, Deuel and 7 more	113 min

Nearby

Mesoscale Discussions in Nebraska, 2009 Every mesoscale discussion in 2009

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.