Alert archive / Nebraska / Mesoscale Discussions in 2023

Mesoscale Discussion 1321

June 28, 20234 states

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2023, 5:16 PM MDT for 4 states. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: Jun 28, 2023, 5:16 PM MDT (23:16 UTC)
Expired: Jun 28, 2023, 7:15 PM MDT
In force: 119 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 408

All 27 counties

Sedgwick County, CO, Arthur County, NE, Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Bennett County, SD, Custer County, SD, Fall River County, SD, Jackson County, SD, Lawrence County, SD, Oglala Lakota County, SD, Pennington County, SD, Goshen County, WY, Niobrara County, WY, Platte County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 165 km from the middle of the area, began a volume at 23:19 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 410Jun 28, 9:05 PM MDT

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 11.3 hours before the alert went out and 159 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: 1886 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: -54 m²/s²
0-3 km storm-relative helicity: 11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

864 
ACUS11 KWNS 282316
SWOMCD
SPC MCD 282316 
NEZ000-SDZ000-COZ000-WYZ000-290115-

Mesoscale Discussion 1321
NWS Storm Prediction Center Norman OK
0616 PM CDT Wed Jun 28 2023

Areas affected...portions of eastern WY...western SD...and the NE
Panhandle

Concerning...Severe Thunderstorm Watch 408...

Valid 282316Z - 290115Z

The severe weather threat for Severe Thunderstorm Watch 408
continues.

SUMMARY...Ongoing severe storms should continue to pose a risk for
large to very large hail and damaging gusts tonight. A downstream
watch and or local extensions may be needed later this evening.

DISCUSSION...Across WW408, several mature storms, including a few
supercell, are ongoing late this afternoon/evening. Several reports
of severe hail have been received over the last couple of hours as
storms have maintained themselves. This should continue with hi-res
guidance and observational trends showing storms maintaining
intensity and the subsequent severe risk into this evening. The
environment across the central High Plains remains favorable for
supercells with moderate MLCAPE and 40-50 kt of effective shear.
Steep mid-level lapse rates and a discrete storm mode suggest large
to very large hail and isolated damaging gusts are likely into this
evening. A tornado or two may also be possible with the more
discrete supercells, though low-level flow is generally weak. As
storms approach the eastern edge of WW408 later this evening the
severe risk may continue farther east. Local extensions or a new
watch will need to be considered in the next couple of hours pending
convective trends.

..Lyons/Hart.. 06/28/2023

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

ATTN...WFO...LBF...UNR...BOU...CYS...

LAT...LON   44090213 43580123 42880105 42390110 41770112 41270140
            41020168 40690235 40690275 40750319 40860377 41150455
            42470518 43320541 43910500 44330462 44470442 44590289
            44550272 44090213

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 28, 5:32 PM MDT	Mesoscale Discussion	SPC	Baca, Prowers	88 min
Jun 27, 6:26 PM MDT	Mesoscale Discussion	SPC	Antelope, Blaine, Boyd, Brown, Buffalo, Custer and 20 more	2 hr
Jun 27, 8:38 PM MDT	Mesoscale Discussion	SPC	Blaine, Brown, Cherry, Hooker, Keya Paha, Logan and 2 more	97 min
Jun 28, 1:21 PM MDT	Mesoscale Discussion	SPC	Banner, Box Butte, Dawes, Kimball, Morrill, Scotts Bluff and 1 more	84 min
Jun 28, 1:56 PM MDT	Severe Thunderstorm Watch	SPC	Banner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 5 more	7 hr
Jun 27, 7:29 PM MDT	Severe Thunderstorm Watch	SPC	Brule, Buffalo, Charles Mix, Gregory, Hughes, Jones and 3 more	3 hr

Nearby

Mesoscale Discussions in Nebraska, 2023 Mesoscale Discussions in South Dakota, 2023 Mesoscale Discussions in Wyoming, 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.