Alert archive / Kansas / Mesoscale Discussions in 2021
Mesoscale Discussion 1509
The Storm Prediction Center issued this mesoscale discussion at Aug 12, 2021, 10:20 PM CDT for 33 counties in Kansas; 24 counties in Missouri; 5 counties in Nebraska. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 12, 2021, 10:20 PM CDT (03:20 UTC)
- Expired
- Aug 13, 2021, 12:45 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
All 62 counties
Anderson County, KS, Atchison County, KS, Brown County, KS, Chase County, KS, Clay County, KS, Cloud County, KS, Coffey County, KS, Dickinson County, KS, Doniphan County, KS, Douglas County, KS, Franklin County, KS, Geary County, KS, Jackson County, KS, Jefferson County, KS, Johnson County, KS, Leavenworth County, KS, Linn County, KS, Lyon County, KS, Marion County, KS, Marshall County, KS, Miami County, KS, Morris County, KS, Nemaha County, KS, Osage County, KS, Ottawa County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Saline County, KS, Shawnee County, KS, Wabaunsee County, KS, Washington County, KS, Wyandotte County, KS, Andrew County, MO, Atchison County, MO, Bates County, MO, Buchanan County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Clay County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Henry County, MO, Holt County, MO, Jackson County, MO, Johnson County, MO, Lafayette County, MO, Livingston County, MO, Nodaway County, MO, Pettis County, MO, Platte County, MO, Ray County, MO, Saline County, MO, Gage County, NE, Jefferson County, NE, Nemaha County, NE, Pawnee County, NE, Richardson County, NE
The radar
The Topeka radar (KTWX), 77 km from the middle of the area, began a volume at 03:22 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
Topeka, KS (KTOP), launched 00:00Z, 3.3 hours before the alert went out and 32 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
- 4214 J/kg
- Mixed-layer CIN
- -86 J/kg
- Mixed-layer LCL
- 1420 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 110 m²/s²
- 0-3 km storm-relative helicity
- 179 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 6.4
The text
As transmitted.
290
ACUS11 KWNS 130320
SWOMCD
SPC MCD 130320
MOZ000-KSZ000-NEZ000-130545-
Mesoscale Discussion 1509
NWS Storm Prediction Center Norman OK
1020 PM CDT Thu Aug 12 2021
Areas affected...Northeast KS...Northwest MO...Southeast NE
Concerning...Severe potential...Watch unlikely
Valid 130320Z - 130545Z
Probability of Watch Issuance...20 percent
SUMMARY...Sporadic intense thunderstorm development may continue
overnight, with a threat of isolated severe hail and wind.
DISCUSSION...Periodic intense thunderstorm development has been
noted for much of the evening across northeast KS and northwest MO,
with a few reports of severe hail since 00Z. This activity is being
supported by strong elevated buoyancy, as observed in the 00Z TOP
sounding. While generally weak vertical shear will continue to limit
storm organization, a modest low-level warm advection regime will
continue to support occasional strong thunderstorm development
overnight, with the strongest cells capable of hail and isolated
strong wind gusts.
..Dean/Goss.. 08/13/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SGF...EAX...OAX...TOP...ICT...GID...
LAT...LON 38169434 38209659 38409757 38979797 39729800 40259728
40469531 40199362 40089347 39589308 38349306 38169434SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 7:20 PM CDT | Mesoscale Discussion | SPC | Bollinger, Cape Girardeau, Madison, Perry, Scott, Stoddard and 1 more | 85 min |
| Aug 12, 7:37 PM CDT | Severe Thunderstorm Watch | SPC | Bollinger, Cape Girardeau, Mississippi, New Madrid, Perry, Scott and 1 more | 4 hr |
| Aug 12, 9:55 PM CDT | Mesoscale Discussion | SPC | Bollinger, Butler, Cape Girardeau, Carter, Mississippi, New Madrid and 4 more | 95 min |
Nearby
Mesoscale Discussions in Kansas, 2021Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Nebraska, 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.