Alert archive / Nebraska / Mesoscale Discussions in 2021
Mesoscale Discussion 1563
The Storm Prediction Center issued this mesoscale discussion at Aug 19, 2021, 5:17 PM MDT for 4 counties in Colorado; 5 counties in Kansas; 8 counties in Nebraska. It was in force for 28 min.
The area
The outline as issued.
The facts
- Issued
- Aug 19, 2021, 5:17 PM MDT (23:17 UTC)
- Expired
- Aug 19, 2021, 5:45 PM MDT
- In force
- 28 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 449
Counties Kit Carson County, CO, Phillips County, CO, Sedgwick County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Rawlins County, KS, Sherman County, KS, Thomas County, KS, Chase County, NE, Dundy County, NE, Hayes County, NE, Hitchcock County, NE, Keith County, NE, Lincoln County, NE, Perkins County, NE, Red Willow County, NE
The radar
The Goodland radar (KGLD), 69 km from the middle of the area, began a volume at 23:18 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
Denver, CO (KDNR), launched 12:00Z, 11.3 hours before the alert went out and 129 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
- 246 J/kg
- Mixed-layer CIN
- -241 J/kg
- Mixed-layer LCL
- 927 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- -59 m²/s²
- 0-3 km storm-relative helicity
- 35 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
389
ACUS11 KWNS 192317
SWOMCD
SPC MCD 192317
NEZ000-KSZ000-COZ000-192345-
Mesoscale Discussion 1563
NWS Storm Prediction Center Norman OK
0617 PM CDT Thu Aug 19 2021
Areas affected...Western Kansas...northeast Colorado...southwest
Nebraska
Concerning...Severe Thunderstorm Watch 449...
Valid 192317Z - 192345Z
The severe weather threat for Severe Thunderstorm Watch 449
continues.
SUMMARY...Increase tornado potential will necessitate a tornado
watch issuance shortly.
DISCUSSION...Regional surface observations show rich low-level
moisture over portions of western Kansas, with upper 60s F dew point
temperatures. Forecast soundings suggest enlarging hodographs and
thus low-level shear should increase substantially over the next 1-3
hours as decoupling and low-level jet onset occurs. Given the rich
kinematic and thermodynamic environment in place, an increase in
tornado potential appears likely this evening, which will
necessitate a small tornado watch issuance shortly.
..Karstens.. 08/19/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...GLD...BOU...
LAT...LON 39170262 38970177 39180075 39950037 41180051 41340169
41000244 39890271 39170262SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 12:00 PM MDT | Mesoscale Discussion | SPC | Cheyenne, Kit Carson, Lincoln, Logan, Phillips, Sedgwick and 2 more | 2 hr |
| Aug 19, 1:14 PM MDT | Severe Thunderstorm Watch | SPC | Adams, Arapahoe, Cheyenne, Denver, Elbert, El Paso and 11 more | 6 hr |
| Aug 19, 5:25 PM MDT | Tornado Watch | SPC | Logan, Phillips, Sedgwick, Washington, Yuma | 6 hr |
| Aug 19, 2:29 PM MDT | Mesoscale Discussion | SPC | Clark, Finney, Ford, Grant, Gray, Hamilton and 7 more | 2 hr |
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.