Alert archive / Kansas / Mesoscale Discussions in 2021

Mesoscale Discussion 925

June 11, 202137 counties in Kansas; 34 counties in Missouri; Craig County, Nowata County, Ottawa County, Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2021, 2:52 PM CDT for 37 counties in Kansas; 34 counties in Missouri; Craig County, Nowata County, Ottawa County, Oklahoma. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
Jun 11, 2021, 2:52 PM CDT (19:52 UTC)
Expired
Jun 11, 2021, 4:45 PM CDT
In force
113 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 259
All 74 counties

Allen County, KS, Anderson County, KS, Atchison County, KS, Bourbon County, KS, Butler County, KS, Chase County, KS, Chautauqua County, KS, Cherokee County, KS, Coffey County, KS, Cowley County, KS, Crawford County, KS, Dickinson County, KS, Doniphan County, KS, Douglas County, KS, Elk County, KS, Franklin County, KS, Geary County, KS, Greenwood County, KS, Jackson County, KS, Jefferson County, KS, Johnson County, KS, Labette County, KS, Leavenworth County, KS, Linn County, KS, Lyon County, KS, Marion County, KS, Miami County, KS, Montgomery County, KS, Morris County, KS, Neosho County, KS, Osage County, KS, Pottawatomie County, KS, Shawnee County, KS, Wabaunsee County, KS, Wilson County, KS, Woodson County, KS, Wyandotte County, KS, Andrew County, MO, Barton County, MO, Bates County, MO, Benton County, MO, Buchanan County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Cedar County, MO, Christian County, MO, Clay County, MO, Clinton County, MO, Dade County, MO, Dallas County, MO, Daviess County, MO, DeKalb County, MO, Greene County, MO, Henry County, MO, Hickory County, MO, Jackson County, MO, Jasper County, MO, Johnson County, MO, Lafayette County, MO, Lawrence County, MO, Livingston County, MO, Newton County, MO, Pettis County, MO, Platte County, MO, Polk County, MO, Ray County, MO, Saline County, MO, St. Clair County, MO, Vernon County, MO, Webster County, MO, Craig County, OK, Nowata County, OK, Ottawa County, OK

The radar

The Pleasant Hill radar (KEAX), 70 km from the middle of the area, began a volume at 19:55 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, 7.9 hours before the alert went out and 120 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.

Skew-T log-pSkew-T log-p diagram, Topeka, KS at 12:00Z on 2021-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2135 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Topeka, KS at 12:00Z on 2021-06-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
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

Open this sounding in Storm Lab

The text

As transmitted.

285 
ACUS11 KWNS 111953
SWOMCD
SPC MCD 111952 
MOZ000-KSZ000-OKZ000-112145-

Mesoscale Discussion 0925
NWS Storm Prediction Center Norman OK
0252 PM CDT Fri Jun 11 2021

Areas affected...portions of southeast Kansas...far northeast
Oklahoma...southwest Missouri

Concerning...Severe Thunderstorm Watch 259...

Valid 111952Z - 112145Z

The severe weather threat for Severe Thunderstorm Watch 259
continues.

SUMMARY...The severe threat continues across Severe Thunderstorm
Watch 259 in association with a long-lived MCS. Damaging winds, some
significant, are expected to continue through the afternoon, and
conditions are being monitored for a downstream Severe Thunderstorm
Watch.

DISCUSSION...A mature MCS is underway across far northeast Kansas,
with a history of producing damaging winds, with up to 75 kts
recently reported. KEAX velocity data shows the presence of a
rear-inflow jet associated with the apex of a bowing segment within
the MCS, suggesting that the MCS continues to intensify as MLCINH
gradually erodes, and that the damaging wind threat will likely
continue for several more hours. Stronger MLCINH to the west and
weaker low-level mass convergence along the leading edge of the MCS
cold pool has resulted in weaker convective development from
Wabaunsee County, KS westward. As such, questions remain regarding
whether this portion of the MCS will strengthen to support severe
winds.

Nonetheless, the most intense segment of the MCS straddling the
KS/MO border is expected to persist southward for several more hours
along an MUCAPE gradient. Given up to 4000 J/kg MUCAPE and and mixed
boundary layer present, at least a few more significant-severe gusts
remain possible. Conditions continue to be monitored for a
downstream Severe Thunderstorm Watch issuance, with the most likely
area for watch placement being across portions of far southeast
KS/northeast OK into southwest MO.

..Squitieri/Grams.. 06/11/2021

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

ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN...

LAT...LON   39999335 39389310 38809311 38439306 37939276 37379265
            37079259 36879295 36799356 36779468 36759542 36769649
            36889703 37389732 38169737 38889740 39289661 39629571
            40099498 40139402 39999335

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 8:30 AM CDTSevere Thunderstorm WatchSPCAtchison, Brown, Clay, Doniphan, Jackson, Marshall and 4 more7 hr
Jun 11, 10:28 AM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Jackson, Marshall, Nemaha and 1 more2 hr
Jun 11, 12:32 PM CDTSevere Thunderstorm WatchSPCAllen, Anderson, Butler, Chase, Coffey, Dickinson and 17 more6 hr
Jun 11, 1:55 PM CDTMesoscale DiscussionSPCDouglas, Franklin, Jefferson, Johnson, Leavenworth, Miami and 3 more95 min
Jun 11, 3:28 PM CDTMesoscale DiscussionSPCAnderson, Franklin, Johnson, Linn, Miami92 min
Jun 11, 3:54 PM CDTSevere Thunderstorm WatchSPCBourbon, Cherokee, Crawford6 hr
Jun 11, 5:39 PM CDTMesoscale DiscussionSPCAllen, Anderson, Bourbon, Cherokee, Coffey, Crawford and 13 more2 hr
Jun 11, 6:18 PM CDTMesoscale DiscussionSPCButler, Chautauqua, Cherokee, Cowley, Elk, Greenwood and 10 more117 min
Jun 11, 6:46 PM CDTSevere Thunderstorm WatchSPCAllen, Butler, Chase, Chautauqua, Cowley, Elk and 10 more7 hr

Nearby

Mesoscale Discussions in Kansas, 2021Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Oklahoma, 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.