Alert archive / South Dakota / Mesoscale Discussions in 2020

Mesoscale Discussion 694

May 23, 202019 counties in Nebraska; 23 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 23, 2020, 7:53 PM CDT for 19 counties in Nebraska; 23 counties in South Dakota. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
May 23, 2020, 7:53 PM CDT (00:53 UTC)
Expired
May 23, 2020, 9:30 PM CDT
In force
97 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch likely
Chance of a watch
95%
All 42 counties

Blaine County, NE, Boyd County, NE, Brown County, NE, Cherry County, NE, Custer County, NE, Dawson County, NE, Frontier County, NE, Garfield County, NE, Hayes County, NE, Holt County, NE, Hooker County, NE, Keya Paha County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Rock County, NE, Thomas County, NE, Valley County, NE, Aurora County, SD, Brule County, SD, Buffalo County, SD, Campbell County, SD, Charles Mix County, SD, Corson County, SD, Dewey County, SD, Edmunds County, SD, Faulk County, SD, Gregory County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jerauld County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD

The radar

The North Platte radar (KLNX), 154 km from the middle of the area, began a volume at 00:55 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.

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 0.9 hours before the alert went out and 245 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-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 00:00Z on 2020-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 896 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 00:00Z on 2020-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
896 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
1229 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
144 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.0

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.

IssuedProductOfficeCountiesLasted
May 23, 8:29 PM CDTSevere Thunderstorm WatchSPCArthur, Blaine, Brown, Chase, Cherry, Custer and 16 more5 hr
May 23, 11:08 PM CDTMesoscale DiscussionSPCBlaine, Brown, Custer, Dawson, Lincoln, Logan and 4 more2 hr
May 23, 11:58 PM CDTSevere Thunderstorm WatchSPCAntelope, Boone, Boyd, Burt, Butler, Cass and 30 more6 hr
May 24, 1:20 AM CDTMesoscale DiscussionSPCBoone, Greeley, Nance, Valley, Wheeler55 min
May 24, 4:13 AM CDTMesoscale DiscussionSPCCass, Otoe62 min
May 24, 5:30 AM CDTSevere Thunderstorm WatchSPCCass, Otoe4 hr
May 24, 1:13 PM CDTMesoscale DiscussionSPCCass, Gage, Johnson, Nemaha, Otoe, Pawnee and 1 more92 min
May 24, 1:40 PM CDTSevere Thunderstorm WatchSPCButler, Cass, Dodge, Douglas, Gage, Jefferson and 11 more6 hr
May 24, 3:25 PM CDTMesoscale DiscussionSPCCass, Douglas, Johnson, Nemaha, Otoe, Richardson and 2 more95 min
May 24, 5:14 PM CDTMesoscale DiscussionSPCAdams, Clay, Fillmore, Franklin, Harlan, Nuckolls and 2 more91 min
May 24, 5:36 PM CDTSevere Thunderstorm WatchSPCClay, Fillmore, Nuckolls, Thayer, Webster6 hr

Nearby

Mesoscale Discussions in South Dakota, 2020Mesoscale Discussions in Nebraska, 2020Every mesoscale discussion in 2020

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.