Alert archive / Nebraska / Mesoscale Discussions in 2021
Mesoscale Discussion 870
The Storm Prediction Center issued this mesoscale discussion at Jun 7, 2021, 2:49 PM MDT for 9 counties in Nebraska; 8 counties in South Dakota; 4 counties in Wyoming. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- Jun 7, 2021, 2:49 PM MDT (20:49 UTC)
- Expired
- Jun 7, 2021, 4:45 PM MDT
- In force
- 116 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
All 21 counties
Banner County, NE, Box Butte County, NE, Dawes County, NE, Garden 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, Haakon County, SD, Jackson County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Goshen County, WY, Laramie County, WY, Niobrara County, WY, Platte County, WY
The radar
The Rapid City radar (KUDX), 177 km from the middle of the area, began a volume at 20:48 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 (KUNR), launched 12:00Z, 8.8 hours before the alert went out and 170 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.
- Mixed-layer CAPE
- 43 J/kg
- Mixed-layer CIN
- -864 J/kg
- Mixed-layer LCL
- 1770 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 338 m²/s²
- 0-3 km storm-relative helicity
- 397 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
729
ACUS11 KWNS 072049
SWOMCD
SPC MCD 072049
NEZ000-SDZ000-WYZ000-072245-
Mesoscale Discussion 0870
NWS Storm Prediction Center Norman OK
0349 PM CDT Mon Jun 07 2021
Areas affected...Far Eastern Wyoming...Nebraska
Panhandle...southwestern South Dakota
Concerning...Severe potential...Watch unlikely
Valid 072049Z - 072245Z
Probability of Watch Issuance...20 percent
SUMMARY...Strong to severe wind gusts are the most likely threat for
storms moving northeast out of eastern Wyoming. Isolated large hail
may occur as well. Storm organization and coverage will be limited.
No WW is expected.
DISCUSSION...Strong surface heating has allowed surface temperatures
to rise into the low 90s F. Storms have initiated within the Laramie
Mountains vicinity and are likely to slowly move northeast with
time. While hail is possible, very modest low-level moisture and
buoyancy will likely keep most hail small with marginally severe
hail remaining isolated. There is a higher probability of strong to
severe wind gusts given the very deep boundary layer. Weakly rising
heights will tend to keep storm coverage low and shear is rather
weak for significant storm organization. Some increase in intensity
could occur as activity moves into marginally greater boundary layer
moisture on the plains, but a WW is not expected for this activity.
..Wendt/Guyer.. 06/07/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...UNR...CYS...
LAT...LON 42620497 44000420 44710264 44680170 44010109 42050196
41470238 41260272 41180382 41080456 41270503 42620497SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 7, 4:08 PM MDT | Mesoscale Discussion | SPC | Brown, Campbell, Edmunds, Faulk, McPherson, Potter and 1 more | 97 min |
| Jun 7, 4:45 PM MDT | Severe Thunderstorm Watch | SPC | Campbell, Edmunds, McPherson, Walworth | 8 hr |
Nearby
Mesoscale Discussions in Nebraska, 2021Mesoscale Discussions in South Dakota, 2021Mesoscale Discussions in Wyoming, 2021Every 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.