Alert archive / Nebraska / Mesoscale Discussions in 2014

Mesoscale Discussion 515

May 7, 201421 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 7, 2014, 6:54 PM CDT for 21 counties in Nebraska. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: May 7, 2014, 6:54 PM CDT (23:54 UTC)
Expired: May 7, 2014, 8:00 PM CDT
In force: 66 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 21 counties

Adams County, NE, Antelope County, NE, Boone County, NE, Buffalo County, NE, Custer County, NE, Dawson County, NE, Garfield County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Howard County, NE, Kearney County, NE, Loup County, NE, Merrick County, NE, Nance County, NE, Phelps County, NE, Sherman County, NE, Valley County, NE, Wheeler County, NE

The radar

The Grand Island radar (KUEX), 111 km from the middle of the area, began a volume at 23:55 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.

Severe Thunderstorm Watch 127May 7, 7:25 PM CDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 11.9 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: 120 J/kg
Mixed-layer CIN: -383 J/kg
Mixed-layer LCL: 799 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: -31 m²/s²
0-3 km storm-relative helicity: 78 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

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
May 6, 7:06 PM CDT	Mesoscale Discussion	SPC	Banner, Scotts Bluff	54 min
May 7, 12:52 AM CDT	Mesoscale Discussion	SPC	Arthur, Cheyenne, Deuel, Garden, Keith, Kimball and 1 more	2 hr
May 7, 12:59 PM CDT	Mesoscale Discussion	SPC	Arthur, Banner, Chase, Cheyenne, Deuel, Dundy and 6 more	2 hr
May 7, 1:37 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Banner, Chase, Cheyenne, Deuel, Dundy and 16 more	7 hr
May 7, 5:05 PM CDT	Mesoscale Discussion	SPC	Arthur, Banner, Chase, Cheyenne, Deuel, Dundy and 8 more	85 min

Nearby

Mesoscale Discussions in Nebraska, 2014 Every mesoscale discussion in 2014

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.