Alert archive / Oklahoma / Mesoscale Discussions in 2021
Mesoscale Discussion 929
The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2021, 6:18 PM CDT for 16 counties in Kansas; 19 counties in Oklahoma. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- Jun 11, 2021, 6:18 PM CDT (23:18 UTC)
- Expired
- Jun 11, 2021, 8:15 PM CDT
- In force
- 117 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch likely
- Chance of a watch
- 80%
All 35 counties
Butler County, KS, Chautauqua County, KS, Cherokee County, KS, Cowley County, KS, Elk County, KS, Greenwood County, KS, Harper County, KS, Harvey County, KS, Labette County, KS, Marion County, KS, Montgomery County, KS, Neosho County, KS, Sedgwick County, KS, Sumner County, KS, Wilson County, KS, Woodson County, KS, Cherokee County, OK, Craig County, OK, Creek County, OK, Delaware County, OK, Garfield County, OK, Grant County, OK, Kay County, OK, Logan County, OK, Mayes County, OK, Noble County, OK, Nowata County, OK, Osage County, OK, Ottawa County, OK, Pawnee County, OK, Payne County, OK, Rogers County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK
The radar
The Wichita radar (KICT), 102 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
Topeka, KS (KTOP), launched 12:00Z, 11.3 hours before the alert went out and 233 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
- 2135 J/kg
- Mixed-layer CIN
- -160 J/kg
- Mixed-layer LCL
- 1019 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 3 m²/s²
- 0-3 km storm-relative helicity
- 72 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -1.2
The text
As transmitted.
280
ACUS11 KWNS 112319
SWOMCD
SPC MCD 112318
OKZ000-KSZ000-120115-
Mesoscale Discussion 0929
NWS Storm Prediction Center Norman OK
0618 PM CDT Fri Jun 11 2021
Areas affected...Southeast Kansas and northeast Oklahoma
Concerning...Severe potential...Watch likely
Valid 112318Z - 120115Z
Probability of Watch Issuance...80 percent
SUMMARY...A southward-propagating MCS may evolve across parts of
southeast Kansas over the next hour and will pose a severe wind
threat as it moves into northeast Oklahoma. A downstream watch from
WW 259 is likely within the next 1-2 hours.
DISCUSSION...GOES visible imagery and reflectivity trends from KICT
show increasingly agitated cumulus and weak returns near the
intersection of a convective outflow boundary from earlier storms
over northeast KS and along a surface trough/cold front.
Additionally, an existing severe cluster over southeast KS is
becoming increasingly organized and is showing signs of southward
propagation. Recent RAP mesoanalysis suggests only modest MLCIN
remains in place along the eastern OK/KS border, and deep-layer
shear parallel to the initiating outflow boundary will likely foster
upscale growth as convection tries to mature. As such, an MCS may
begin to develop over the next 1-2 hours across southeast KS, which
will likely propagate to the south/southeast into northeast OK
through the evening hours. Increasing capping with southern and
western extent introduce some uncertainty into the spatial coverage
of this threat and the propensity of new convection along the cold
front/outflow intersection. However if/when an MCS develops, severe
winds will remain the primary hazard given ample instability and
strong DCAPE. A downstream watch is likely.
..Moore/Dial.. 06/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SGF...TSA...TOP...ICT...OUN...
LAT...LON 36969820 37429798 38009754 38339726 38459694 38319666
38129615 37799504 37399486 36479466 35949479 35739521
35689588 35739701 35939751 36469807 36969820SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 11, 8:30 AM CDT | Severe Thunderstorm Watch | SPC | Atchison, Brown, Clay, Doniphan, Jackson, Marshall and 4 more | 7 hr |
| Jun 11, 10:28 AM CDT | Mesoscale Discussion | SPC | Atchison, Brown, Doniphan, Jackson, Marshall, Nemaha and 1 more | 2 hr |
| Jun 11, 12:32 PM CDT | Severe Thunderstorm Watch | SPC | Allen, Anderson, Butler, Chase, Coffey, Dickinson and 17 more | 6 hr |
| Jun 11, 1:55 PM CDT | Mesoscale Discussion | SPC | Douglas, Franklin, Jefferson, Johnson, Leavenworth, Miami and 3 more | 95 min |
| Jun 11, 2:52 PM CDT | Mesoscale Discussion | SPC | Allen, Anderson, Atchison, Bourbon, Butler, Chase and 31 more | 113 min |
| Jun 11, 3:28 PM CDT | Mesoscale Discussion | SPC | Anderson, Franklin, Johnson, Linn, Miami | 92 min |
| Jun 11, 3:54 PM CDT | Severe Thunderstorm Watch | SPC | Bourbon, Cherokee, Crawford | 6 hr |
| Jun 11, 5:39 PM CDT | Mesoscale Discussion | SPC | Allen, Anderson, Bourbon, Cherokee, Coffey, Crawford and 13 more | 2 hr |
| Jun 11, 6:46 PM CDT | Severe Thunderstorm Watch | SPC | Allen, Butler, Chase, Chautauqua, Cowley, Elk and 10 more | 7 hr |
Nearby
Mesoscale Discussions in Oklahoma, 2021Mesoscale Discussions in Kansas, 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.