Alert archive / Nebraska / Mesoscale Discussions in 2021
Mesoscale Discussion 1527
The Storm Prediction Center issued this mesoscale discussion at Aug 14, 2021, 6:37 PM MDT for 4 counties in Colorado; 5 counties in Kansas; 16 counties in Nebraska. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- Aug 14, 2021, 6:37 PM MDT (00:37 UTC)
- Expired
- Aug 14, 2021, 7:30 PM MDT
- In force
- 53 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 440
All 25 counties
Logan County, CO, Phillips County, CO, Sedgwick County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Rawlins County, KS, Sheridan County, KS, Thomas County, KS, Arthur County, NE, Box Butte County, NE, Chase County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Dundy County, NE, Garden County, NE, Hayes County, NE, Hitchcock County, NE, Keith County, NE, Kimball County, NE, Morrill County, NE, Perkins County, NE, Red Willow County, NE, Sheridan County, NE
The radar
The Goodland radar (KGLD), 151 km from the middle of the area, began a volume at 00:38 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
N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 0.6 hours before the alert went out and 119 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
- 1783 J/kg
- Mixed-layer CIN
- -76 J/kg
- Mixed-layer LCL
- 1421 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 68 m²/s²
- 0-3 km storm-relative helicity
- 276 m²/s²
- Significant tornado parameter
- 1.0
- Supercell composite
- 16.9
The text
As transmitted.
796
ACUS11 KWNS 150037
SWOMCD
SPC MCD 150037
NEZ000-KSZ000-COZ000-SDZ000-150130-
Mesoscale Discussion 1527
NWS Storm Prediction Center Norman OK
0737 PM CDT Sat Aug 14 2021
Areas affected...NE Panhandle and southwest NE...northeast
CO...northwest KS
Concerning...Severe Thunderstorm Watch 440...
Valid 150037Z - 150130Z
The severe weather threat for Severe Thunderstorm Watch 440
continues.
SUMMARY...The threat for large hail will continue through the
evening. The risk for severe gusts may increase---conditional on
additional storms developing/coalescing and becoming more outflow
dominant.
DISCUSSION...Radar imagery this evening shows several intense/severe
thunderstorms mainly over the western half of SD south-southwestward
into the NE Panhandle. The 00z North Platte, NE raob showed
moderate buoyancy (2100 J/kg MLCAPE) and a wind profile veering from
southeast at the surface to north-northwest with 50 kt near 200 mb.
It appears the SPC Mesoanalysis/RAP-based scheme is over-estimating
buoyancy in western NE when compared to the raob. Regardless, ample
shear/buoyancy is currently present this evening for supercells.
Hail will be the primary severe concern for the next 1-2 hours over
the NE Panhandle vicinity.
As the boundary layer begins to cool this evening, a strengthening
LLJ/WAA will attempt to offset the limiting effect of increasing
convective inhibition has on additional storm development. Based on
recent trends in visible-satellite imagery, it remains unclear and
less likely with time that a storm will develop over northwest KS
early this evening. However, the activity over western NE may
eventually move southeast into southwest NE and perhaps northwest KS
by late this evening. Isolated severe gusts would be the main
concern with this potential activity late.
..Smith.. 08/15/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...UNR...GLD...BOU...CYS...
LAT...LON 39120054 39210108 39680269 41200375 42700359 43260337
43220295 40120040 39510017 39120054SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 15, 5:05 PM MDT | Mesoscale Discussion | SPC | Barton, Decatur, Ellis, Ellsworth, Gove, Graham and 13 more | 85 min |
Nearby
Mesoscale Discussions in Nebraska, 2021Mesoscale Discussions in Kansas, 2021Mesoscale Discussions in Colorado, 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.