Alert archive / Nebraska / Mesoscale Discussions in 2021

Mesoscale Discussion 1146

July 3, 20214 states

The Storm Prediction Center issued this mesoscale discussion at Jul 3, 2021, 5:33 PM MDT for 4 states. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: Jul 3, 2021, 5:33 PM MDT (23:33 UTC)
Expired: Jul 3, 2021, 7:00 PM MDT
In force: 87 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 332

All 60 counties

Adams County, CO, Arapahoe County, CO, Bent County, CO, Cheyenne County, CO, Crowley County, CO, El Paso County, CO, Elbert County, CO, Kiowa County, CO, Kit Carson County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Otero County, CO, Phillips County, CO, Prowers County, CO, Pueblo County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Cheyenne County, KS, Sherman County, KS, Wallace County, KS, Arthur County, NE, Banner County, NE, Box Butte County, NE, Brown County, NE, Chase County, NE, Cherry County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Dundy County, NE, Garden County, NE, Grant County, NE, Hayes County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Kimball County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Scotts Bluff County, NE, Sheridan County, NE, Thomas County, NE, Bennett County, SD, Brule County, SD, Haakon County, SD, Hughes County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Oglala Lakota County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD

The radar

The Goodland radar (KGLD), 182 km from the middle of the area, began a volume at 23:32 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

Denver, CO (KDNR), launched 12:00Z, 11.6 hours before the alert went out and 137 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: 2605 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

186 
ACUS11 KWNS 032334
SWOMCD
SPC MCD 032333 
SDZ000-NEZ000-KSZ000-COZ000-WYZ000-040100-

Mesoscale Discussion 1146
NWS Storm Prediction Center Norman OK
0633 PM CDT Sat Jul 03 2021

Areas affected...south-central South Dakota south into east-central
Colorado

Concerning...Severe Thunderstorm Watch 332...

Valid 032333Z - 040100Z

The severe weather threat for Severe Thunderstorm Watch 332
continues.

SUMMARY...Thunderstorm clusters will continue this afternoon and
evening posing a risk for hail and wind. The threat should diminish
this evening with the loss of daytime heating.

DISCUSSION...Clusters of thunderstorms continue within a broad
surface-convergent zone associated with a lee trough. Surface
temperatures in the upper 80s F to lower 90s F and dewpoint
temperatures around 60 F have contributed to CAPE values ranging
from 1000-2000 J/kg across the High Plains. Marginal deep-layer
shear of between 15-30 knots from north to south across the area has
limited thunderstorm organization to mostly single-cell to
multi-cell clusters. The degree of instability and mid-level lapse
rates around 7-8 C/km will support a hail and wind threat for
another couple hours, before diminishing with the loss of diurnal
heating.

..Marsh.. 07/03/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FSD...ABR...LBF...UNR...GLD...PUB...BOU...CYS...

LAT...LON   37930504 42670363 44890167 44960037 43759903 40530090
            38020216 37620359 37930504

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 3, 1:53 PM MDT	Mesoscale Discussion	SPC	Lincoln, Logan, Morgan, Phillips, Sedgwick, Washington	97 min
Jul 3, 3:33 PM MDT	Severe Thunderstorm Watch	SPC	Bent, Cheyenne, Crowley, Elbert, El Paso, Kiowa and 11 more	6 hr
Jul 3, 2:34 PM MDT	Mesoscale Discussion	SPC	Campbell, Corson, Dewey, Perkins, Ziebach	116 min

Nearby

Mesoscale Discussions in Nebraska, 2021 Mesoscale Discussions in Colorado, 2021 Mesoscale Discussions in South Dakota, 2021 Every mesoscale discussion in 2021

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.