Alert archive / Nebraska / Mesoscale Discussions in 2016

Mesoscale Discussion 1637

September 4, 20168 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Sep 4, 2016, 7:50 PM CDT for 8 counties in Nebraska. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Sep 4, 2016, 7:50 PM CDT (00:50 UTC)
Expired: Sep 4, 2016, 9:45 PM CDT
In force: 115 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Blaine County, NE, Buffalo County, NE, Custer County, NE, Dawson County, NE, Logan County, NE, Loup County, NE, Sherman County, NE, Valley County, NE

The radar

The North Platte radar (KLNX), 92 km from the middle of the area, began a volume at 00:54 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 467Sep 4, 10:40 PM CDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 0.8 hours before the alert went out and 74 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: 2563 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 1408 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 118 m²/s²
0-3 km storm-relative helicity: 237 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 13.6

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
Sep 4, 8:57 PM CDT	Mesoscale Discussion	SPC	Arthur, Chase, Cherry, Dundy, Frontier, Grant and 10 more	93 min
Sep 4, 10:40 PM CDT	Severe Thunderstorm Watch	SPC	Antelope, Blaine, Boone, Boyd, Cedar, Custer and 10 more	4 hr
Sep 5, 1:10 AM CDT	Mesoscale Discussion	SPC	Dakota, Dixon, Thurston	2 hr
Sep 5, 3:08 PM CDT	Mesoscale Discussion	SPC	Blaine, Boyd, Garfield, Holt, Knox, Loup and 3 more	2 hr
Sep 5, 3:30 PM CDT	Mesoscale Discussion	SPC	Frontier, Furnas, Gosper, Harlan, Hitchcock, Phelps and 1 more	90 min
Sep 5, 6:06 PM CDT	Mesoscale Discussion	SPC	Antelope, Blaine, Boone, Buffalo, Custer, Dawson and 18 more	84 min
Sep 5, 6:09 PM CDT	Mesoscale Discussion	SPC	Box Butte, Dawes, Garden, Morrill, Scotts Bluff, Sioux	3 hr

Nearby

Mesoscale Discussions in Nebraska, 2016 Every mesoscale discussion in 2016

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.