Alert archive / South Dakota / Mesoscale Discussions in 2016

Mesoscale Discussion 1733

September 23, 20169 counties in Nebraska; 11 counties in South Dakota; 4 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at Sep 23, 2016, 5:35 PM MDT for 9 counties in Nebraska; 11 counties in South Dakota; 4 counties in Wyoming. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Sep 23, 2016, 5:35 PM MDT (23:35 UTC)
Expired: Sep 23, 2016, 7:00 PM MDT
In force: 85 min
Issued by: the Storm Prediction Center

All 24 counties

Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD, Goshen County, WY, Laramie County, WY, Niobrara County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 39 km from the middle of the area, began a volume at 23:36 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

Rapid City, SD (KRAP), launched 12:00Z, 11.6 hours before the alert went out and 33 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: 3 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 468 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 133 m²/s²
0-3 km storm-relative helicity: 149 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

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
Sep 23, 1:23 PM MDT	Mesoscale Discussion	SPC	Banner, Box Butte, Dawes, Kimball, Morrill, Scotts Bluff and 1 more	67 min
Sep 23, 2:21 PM MDT	Severe Thunderstorm Watch	SPC	Banner, Box Butte, Dawes, Scotts Bluff, Sioux	8 hr

Nearby

Mesoscale Discussions in South Dakota, 2016 Mesoscale Discussions in Nebraska, 2016 Mesoscale Discussions in Wyoming, 2016 Every mesoscale discussion in 2016

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.