Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 1401

September 1, 20189 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Sep 1, 2018, 2:30 AM CDT for 9 counties in Nebraska. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: Sep 1, 2018, 2:30 AM CDT (07:30 UTC)
Expired: Sep 1, 2018, 4:00 AM CDT
In force: 90 min
Issued by: the Storm Prediction Center
Chance of a watch: 5%

Counties Butler County, NE, Colfax County, NE, Dodge County, NE, Hamilton County, NE, Merrick County, NE, Nance County, NE, Platte County, NE, Polk County, NE, York County, NE

The radar

The Omaha radar (KOAX), 102 km from the middle of the area, began a volume at 07:33 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

Omaha, NE (KOAX), launched 00:00Z, 7.5 hours before the alert went out and 102 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: 2615 J/kg
Mixed-layer CIN: -112 J/kg
Mixed-layer LCL: 1197 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 186 m²/s²
0-3 km storm-relative helicity: 306 m²/s²
Significant tornado parameter: 2.2
Supercell composite: 24.5

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 31, 8:47 PM CDT	Mesoscale Discussion	SPC	Burt, Butler, Cass, Dodge, Douglas, Gage and 10 more	118 min
Sep 1, 2:45 PM CDT	Mesoscale Discussion	SPC	Adams, Franklin, Furnas, Harlan, Kearney, Nuckolls and 2 more	2 hr
Sep 1, 4:47 PM CDT	Severe Thunderstorm Watch	SPC	Cass, Clay, Douglas, Fillmore, Gage, Jefferson and 13 more	6 hr
Sep 1, 5:37 PM CDT	Mesoscale Discussion	SPC	Arthur, Chase, Cheyenne, Deuel, Dundy, Garden and 4 more	113 min
Sep 1, 6:34 PM CDT	Mesoscale Discussion	SPC	Burt, Cass, Douglas, Sarpy, Washington	56 min
Sep 1, 6:38 PM CDT	Mesoscale Discussion	SPC	Cass, Clay, Douglas, Fillmore, Gage, Jefferson and 12 more	2 hr

Nearby

Mesoscale Discussions in Nebraska, 2018 Every mesoscale discussion in 2018

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.