Mesoscale Discussion 932

Issued

Jun 11, 2021, 9:20 PM CDT (02:20 UTC)

Expired

Jun 11, 2021, 11:15 PM CDT

In force

115 min

Issued by

the Storm Prediction Center

Concerning

Severe thunderstorm watch 261

Counties Butler County, KS, Chautauqua County, KS, Cowley County, KS, Sedgwick County, KS, Sumner County, KS, Garfield County, OK, Grant County, OK, Kay County, OK, Noble County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK

The Wichita radar (KICT), 82 km from the middle of the area, began a volume at 02:22 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.

191 
ACUS11 KWNS 120221
SWOMCD
SPC MCD 120220 
OKZ000-KSZ000-120415-

Mesoscale Discussion 0932
NWS Storm Prediction Center Norman OK
0920 PM CDT Fri Jun 11 2021

Areas affected...Southern Kansas and northern Oklahoma

Concerning...Severe Thunderstorm Watch 261...

Valid 120220Z - 120415Z

The severe weather threat for Severe Thunderstorm Watch 261
continues.

SUMMARY...Thunderstorms developing near Wichita, KS will continue to
gradually grow upscale and move southward into northern Oklahoma.
These storms may pose a severe wind risk as this occurs, though the
timing and spatial coverage of this threat remains somewhat
uncertain.

DISCUSSION...Reflectivity and velocity data from KICT over the past
1-2 hours has shown discrete cells initiating along a surface
trough/cold front and where this feature intersects a residual
outflow boundary from prior convection. As storms develop near the
cold front/outflow intersection, they have displayed a tendency to
become displaced to the cool (north) side of the boundary.
Convective reinforcement of the boundary has resulted in a southward
boundary motion. Despite deep-layer shear vectors oriented along
this boundary (which should favor upscale growth), the development
of an organized MCS has been largely delayed up until the past 30
minutes.

Recent imagery suggests that cold pool amalgamation may be beginning
as a slight southward propagation in a developing convective cluster
is noted. This feature is expected to continue to push to the
south/southeast and remain in an environment with 3000-4000 J/kg
MLCAPE. Although effective bulk shear values near 40-50 knots are
noted, the line-normal component may be weak and yield an overall
slow southward progression - driven namely by cold-pool propagation.
Additionally, increasing MLCIN introduces some uncertainty into the
propensity for widespread severe/damaging winds. However, given the
ample instability and strong DCAPE, at least periodic severe winds
will remain possible.

..Moore.. 06/12/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TSA...ICT...OUN...

LAT...LON   37629785 37889749 37909676 37619639 37179603 36539589
            36039608 35949679 36009792 36269815 37019812 37629785

Mesoscale Discussions in Oklahoma, 2021Mesoscale Discussions in Kansas, 2021Every mesoscale discussion in 2021

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.