Alert archive / Nebraska / Mesoscale Discussions in 2023

Mesoscale Discussion 554

April 18, 20237 counties in Kansas; 16 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2023, 5:37 PM CDT for 7 counties in Kansas; 16 counties in Nebraska. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Apr 18, 2023, 5:37 PM CDT (22:37 UTC)
Expired: Apr 18, 2023, 9:00 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

All 23 counties

Graham County, KS, Jewell County, KS, Norton County, KS, Phillips County, KS, Republic County, KS, Rooks County, KS, Smith County, KS, Adams County, NE, Buffalo County, NE, Clay County, NE, Dawson County, NE, Fillmore County, NE, Franklin County, NE, Furnas County, NE, Gosper County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Kearney County, NE, Nuckolls County, NE, Phelps County, NE, Thayer County, NE, Webster County, NE

The radar

The Grand Island radar (KUEX), 19 km from the middle of the area, began a volume at 22:38 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

Topeka, KS (KTOP), launched 12:00Z, 10.6 hours before the alert went out and 282 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: 1783 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 339 m²/s²
0-3 km storm-relative helicity: 376 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
Apr 18, 5:46 PM CDT	Mesoscale Discussion	SPC	Box Butte, Dawes, Scotts Bluff, Sheridan, Sioux	2 hr

Nearby

Mesoscale Discussions in Nebraska, 2023 Mesoscale Discussions in Kansas, 2023 Every mesoscale discussion in 2023

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.