Alert archive / Nebraska / Mesoscale Discussions in 2013

Mesoscale Discussion 1587

August 1, 201317 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Aug 1, 2013, 6:02 PM CDT for 17 counties in Nebraska. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Aug 1, 2013, 6:02 PM CDT (23:02 UTC)
Expired: Aug 1, 2013, 7:00 PM CDT
In force: 58 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

Counties Butler County, NE, Cass County, NE, Clay County, NE, Fillmore County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nuckolls County, NE, Otoe County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, York County, NE

The radar

The Omaha radar (KOAX), 83 km from the middle of the area, began a volume at 23:02 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 459Aug 1, 6:10 PM CDT

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.0 hours before the alert went out and 82 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: 580 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 1047 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 37 m²/s²
0-3 km storm-relative helicity: 5 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

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
Aug 1, 8:16 AM CDT	Mesoscale Discussion	SPC	Antelope, Boone, Boyd, Butler, Cedar, Colfax and 23 more	59 min
Aug 1, 12:53 PM CDT	Mesoscale Discussion	SPC	Adams, Arthur, Blaine, Boone, Box Butte, Brown and 52 more	2 hr
Aug 1, 1:22 PM CDT	Tornado Watch	SPC	Antelope, Blaine, Boone, Boyd, Brown, Buffalo and 26 more	9 hr
Aug 1, 2:08 PM CDT	Severe Thunderstorm Watch	SPC	Burt, Cedar, Colfax, Cuming, Dakota, Dixon and 9 more	8 hr
Aug 1, 3:25 PM CDT	Mesoscale Discussion	SPC	Adams, Antelope, Arthur, Blaine, Boone, Box Butte and 57 more	95 min
Aug 1, 3:59 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Banner, Box Butte, Chase, Cheyenne, Dawes and 11 more	9 hr
Aug 1, 5:06 PM CDT	Mesoscale Discussion	SPC	Chase, Dundy, Hitchcock	54 min
Aug 1, 5:09 PM CDT	Severe Thunderstorm Watch	SPC	Dundy, Hitchcock	5 hr
Aug 1, 6:07 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Buffalo, Butler, Cass, Clay, Dawson and 26 more	7 hr
Aug 1, 6:49 PM CDT	Mesoscale Discussion	SPC	Blaine, Brown, Cherry, Custer, Garfield, Grant and 13 more	86 min

Nearby

Mesoscale Discussions in Nebraska, 2013 Every mesoscale discussion in 2013

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.