Alert archive / Nebraska / Mesoscale Discussions in 2015

Mesoscale Discussion 495

May 3, 2015Nemaha County, Kansas; 16 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 3, 2015, 7:06 PM CDT for Nemaha County, Kansas; 16 counties in Nebraska. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: May 3, 2015, 7:06 PM CDT (00:06 UTC)
Expired: May 3, 2015, 8:30 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Nemaha County, KS, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Sarpy County, NE, Saunders County, NE, Washington County, NE

The radar

The Omaha radar (KOAX), 55 km from the middle of the area, began a volume at 00:09 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.

Tornado Watch 127May 3, 9:15 PM CDT

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.1 hours before the alert went out and 54 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: 552 J/kg
Mixed-layer CIN: -245 J/kg
Mixed-layer LCL: 2278 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 45 m²/s²
0-3 km storm-relative helicity: 113 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

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
May 3, 9:13 PM CDT	Tornado Watch	SPC	Brown, Doniphan, Marshall, Nemaha	118 min
May 4, 2:56 PM CDT	Mesoscale Discussion	SPC	Atchison, Barton, Brown, Clay, Cloud, Dickinson and 44 more	2 hr
May 4, 3:26 PM CDT	Severe Thunderstorm Watch	SPC	Atchison, Barton, Brown, Clay, Cloud, Dickinson and 26 more	6 hr
May 4, 6:30 PM CDT	Mesoscale Discussion	SPC	Atchison, Barton, Brown, Clay, Cloud, Dickinson and 33 more	90 min
May 3, 10:22 PM CDT	Mesoscale Discussion	SPC	Gage, Johnson, Nemaha, Pawnee, Richardson	83 min

Nearby

Mesoscale Discussions in Nebraska, 2015 Mesoscale Discussions in Kansas, 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.