Alert archive / Nebraska / Mesoscale Discussions in 2015

Mesoscale Discussion 1784

September 9, 201513 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Sep 9, 2015, 12:47 PM CDT for 13 counties in Nebraska. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Sep 9, 2015, 12:47 PM CDT (17:47 UTC)
Expired: Sep 9, 2015, 2:15 PM CDT
In force: 88 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Adams County, NE, Buffalo County, NE, Garfield County, NE, Greeley County, NE, Hall County, NE, Howard County, NE, Kearney County, NE, Loup County, NE, Merrick County, NE, Phelps County, NE, Sherman County, NE, Valley County, NE, Wheeler County, NE

The radar

The Grand Island radar (KUEX), 106 km from the middle of the area, began a volume at 17:47 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, 5.8 hours before the alert went out and 127 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: 463 J/kg
Mixed-layer CIN: -127 J/kg
Mixed-layer LCL: 850 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 246 m²/s²
0-3 km storm-relative helicity: 255 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.6

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
Sep 9, 2:33 PM CDT	Mesoscale Discussion	SPC	Blaine, Brown, Buffalo, Custer, Dawson, Frontier and 9 more	87 min
Sep 9, 5:10 PM CDT	Mesoscale Discussion	SPC	Antelope, Buffalo, Cedar, Dawson, Furnas, Garfield and 7 more	2 hr

Nearby

Mesoscale Discussions in Nebraska, 2015 Every mesoscale discussion in 2015

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.