Alert archive / Nebraska / Mesoscale Discussions in 2009

Mesoscale Discussion 809

May 13, 200926 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 13, 2009, 12:46 AM CDT for 26 counties in Nebraska. It was in force for 29 min.

The area

The outline as issued.

The facts

Issued: May 13, 2009, 12:46 AM CDT (05:46 UTC)
Expired: May 13, 2009, 1:15 AM CDT
In force: 29 min
Issued by: the Storm Prediction Center

All 26 counties

Antelope County, NE, Blaine County, NE, Boone County, NE, Buffalo County, NE, Cedar County, NE, Custer County, NE, Dawson County, NE, Dixon County, NE, Garfield County, NE, Greeley County, NE, Holt County, NE, Howard County, NE, Knox County, NE, Lincoln County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Pierce County, NE, Platte County, NE, Rock County, NE, Sherman County, NE, Stanton County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE

The radar

The North Platte radar (KLNX), 137 km from the middle of the area, began a volume at 05:50 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, 5.8 hours before the alert went out and 141 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: 276 J/kg
Mixed-layer CIN: -348 J/kg
Mixed-layer LCL: 1901 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 57 m²/s²
0-3 km storm-relative helicity: 177 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
May 12, 7:08 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Blaine, Boyd, Brown, Cherry, Custer and 13 more	7 hr
May 12, 8:42 PM CDT	Mesoscale Discussion	SPC	Boyd, Brown, Cedar, Holt, Keya Paha, Knox and 1 more	93 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.