Alert archive / Nebraska / Mesoscale Discussions in 2024

Mesoscale Discussion 856

May 20, 202430 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 20, 2024, 6:06 PM CDT for 30 counties in Nebraska. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: May 20, 2024, 6:06 PM CDT (23:06 UTC)
Expired: May 20, 2024, 8:00 PM CDT
In force: 114 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 60%

All 30 counties

Adams County, NE, Buffalo County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Douglas County, NE, Fillmore County, NE, Franklin County, NE, Gage County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Jefferson County, NE, Johnson County, NE, Kearney County, NE, Lancaster County, NE, Merrick County, NE, Nance County, NE, Nuckolls County, NE, Otoe County, NE, Phelps County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, Washington County, NE, Webster County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 62 km from the middle of the area, began a volume at 23:06 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 271May 20, 6:30 PM CDT

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 11.1 hours before the alert went out and 274 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1732 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 79 m²/s²
0-3 km storm-relative helicity: 133 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

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
May 20, 3:47 PM CDT	Mesoscale Discussion	SPC	Banner, Cheyenne, Deuel, Kimball	2 hr
May 20, 5:07 PM CDT	Tornado Watch	SPC	Dundy	7 hr
May 20, 5:16 PM CDT	Severe Thunderstorm Watch	SPC	Banner, Cheyenne, Kimball, Morrill, Scotts Bluff	6 hr
May 20, 6:31 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Boone, Buffalo, Burt, Butler, Cass and 37 more	5 hr

Nearby

Mesoscale Discussions in Nebraska, 2024 Every mesoscale discussion in 2024

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.