Alert archive / Nebraska / Mesoscale Discussions in 2012

Mesoscale Discussion 1686

August 2, 201218 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 2, 2012, 4:37 PM MDT for 18 counties in Nebraska. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Aug 2, 2012, 4:37 PM MDT (22:37 UTC)
Expired: Aug 2, 2012, 6:00 PM MDT
In force: 83 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Arthur County, NE, Buffalo County, NE, Custer County, NE, Dawson County, NE, Deuel County, NE, Garden County, NE, Gosper County, NE, Grant County, NE, Hooker County, NE, Kearney County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Phelps County, NE, Thomas County, NE

The radar

The North Platte radar (KLNX), 103 km from the middle of the area, began a volume at 22:37 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 12:00Z, 10.6 hours before the alert went out and 72 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: 452 J/kg
Mixed-layer CIN: -322 J/kg
Mixed-layer LCL: 1193 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: 0 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
Aug 1, 7:19 PM MDT	Mesoscale Discussion	SPC	Antelope, Boone, Boyd, Cedar, Colfax, Cuming and 17 more	56 min
Aug 1, 10:08 PM MDT	Mesoscale Discussion	SPC	Adams, Buffalo, Clay, Fillmore, Franklin, Furnas and 13 more	2 hr

Nearby

Mesoscale Discussions in Nebraska, 2012 Every mesoscale discussion in 2012

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.