Alert archive / Nebraska / Mesoscale Discussions in 2017

Mesoscale Discussion 1490

August 13, 20176 states

The Storm Prediction Center issued this mesoscale discussion at Aug 13, 2017, 6:38 PM MDT for 6 states. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Aug 13, 2017, 6:38 PM MDT (00:38 UTC)
Expired: Aug 13, 2017, 8:15 PM MDT
In force: 97 min
Issued by: the Storm Prediction Center

All 71 counties

Cheyenne County, CO, Kit Carson County, CO, Yuma County, CO, Lyon County, IA, Sioux County, IA, Cheyenne County, KS, Decatur County, KS, Logan County, KS, Norton County, KS, Rawlins County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS, Nobles County, MN, Rock County, MN, Antelope County, NE, Blaine County, NE, Boone County, NE, Boyd County, NE, Buffalo County, NE, Cedar County, NE, Chase County, NE, Custer County, NE, Dawson County, NE, Dixon County, NE, Dundy County, NE, Frontier County, NE, Furnas County, NE, Garfield County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Harlan County, NE, Hayes County, NE, Hitchcock County, NE, Holt County, NE, Howard County, NE, Kearney County, NE, Knox County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Perkins County, NE, Phelps County, NE, Pierce County, NE, Platte County, NE, Red Willow County, NE, Rock County, NE, Sherman County, NE, Stanton County, NE, Thomas County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Hanson County, SD, Hutchinson County, SD, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Grand Island radar (KUEX), 130 km from the middle of the area, began a volume at 00:39 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, 0.6 hours before the alert went out and 73 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: 1439 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 1852 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: 107 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 3.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 13, 8:13 PM MDT	Mesoscale Discussion	SPC	Baca, Bent, Kiowa, Prowers	92 min
Aug 14, 2:32 PM MDT	Mesoscale Discussion	SPC	Baca	2 hr
Aug 13, 10:10 PM MDT	Mesoscale Discussion	SPC	Graham, Norton, Phillips, Rooks, Smith	95 min
Aug 14, 4:36 PM MDT	Mesoscale Discussion	SPC	Butte, Custer, Haakon, Jackson, Lawrence, Meade and 2 more	114 min

Nearby

Mesoscale Discussions in Nebraska, 2017 Mesoscale Discussions in South Dakota, 2017 Mesoscale Discussions in Kansas, 2017 Every mesoscale discussion in 2017

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.