Alert archive / Kansas / Mesoscale Discussions in 2021

Mesoscale Discussion 922

June 11, 20217 counties in Kansas; Atchison County, Holt County, Missouri; 6 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2021, 10:28 AM CDT for 7 counties in Kansas; Atchison County, Holt County, Missouri; 6 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 11, 2021, 10:28 AM CDT (15:28 UTC)
Expired
Jun 11, 2021, 12:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 258

Counties Atchison County, KS, Brown County, KS, Doniphan County, KS, Jackson County, KS, Marshall County, KS, Nemaha County, KS, Pottawatomie County, KS, Atchison County, MO, Holt County, MO, Gage County, NE, Johnson County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE

The radar

The Topeka radar (KTWX), 104 km from the middle of the area, began a volume at 15:29 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, 3.5 hours before the alert went out and 113 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.

927 
ACUS11 KWNS 111529
SWOMCD
SPC MCD 111528 
MOZ000-KSZ000-NEZ000-IAZ000-111730-

Mesoscale Discussion 0922
NWS Storm Prediction Center Norman OK
1028 AM CDT Fri Jun 11 2021

Areas affected...far southeast NE...far northeast KS...far northwest
MO

Concerning...Severe Thunderstorm Watch 258...

Valid 111528Z - 111730Z

The severe weather threat for Severe Thunderstorm Watch 258
continues.

SUMMARY...The risk for severe gusts may gradually increase through
12pm and focus mainly across parts of far southeast NE into
northeast KS.  A new severe thunderstorm watch will likely need to
be issued during the midday hours for eastern KS and possibly the
western tier or two of counties in MO.

DISCUSSION...Radar mosaic at 1020am shows a southward surge to the
MCS over the lower MO Valley, with it expected to push south of a
flanking band of storms on the southwest edge of the complex during
the next 30-60 minutes.  Once this occurs, expecting the limiting
effects of the flanking band to cease (i.e., competing cold pool
development) and the potential for more storm-scale organization to
proceed as it moves south into the moisture/CAPE axis.  Surface
temperatures have warmed into the mid 80s as of 10am with dewpoints
in the mid 70s.  Additional heating south of the thunderstorms will
contribute to additional buoyancy with the 00z HRW-ARW/NSSL forecast
soundings showing 4000-5000 J/kg MLCAPE by noon.  It appears the 00z
model runs of the HRW-ARW and the HRW-NSSL may be best depicting the
placement and speed of the MCS compared to other 00z and 12z HREF
membership and the latest HRRR runs.  The MCS is forecast to reach
the southern edge of the northeastern-most counties of KS by
1200-1230pm.  A coinciding uptick in severe potential will accompany
the squall line.  Isolated to widely scattered severe gusts 60-70
mph are possible.

..Smith.. 06/11/2021

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

ATTN...WFO...EAX...OAX...TOP...

LAT...LON   39369720 40489683 40759566 40259509 39379507 39369720

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, 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, 2:52 PM CDTMesoscale DiscussionSPCAllen, Anderson, Atchison, Bourbon, Butler, Chase and 31 more113 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
Jun 10, 8:28 PM CDTMesoscale DiscussionSPCArthur, Banner, Blaine, Box Butte, Brown, Cherry and 12 more92 min
Jun 10, 9:08 PM CDTSevere Thunderstorm WatchSPCArthur, Banner, Blaine, Box Butte, Brown, Cherry and 12 more6 hr
Jun 10, 11:07 PM CDTMesoscale DiscussionSPCBox Butte, Dawes, Sheridan, Sioux83 min
Jun 11, 12:52 AM CDTMesoscale DiscussionSPCAntelope, Boyd, Cedar, Holt, Keya Paha, Knox and 4 more53 min
Jun 11, 2:15 AM CDTSevere Thunderstorm WatchSPCDakota, Dixon5 hr
Jun 11, 5:36 AM CDTSevere Thunderstorm WatchSPCAntelope, Boone, Burt, Butler, Cedar, Colfax and 22 more5 hr
Jun 11, 7:28 AM CDTMesoscale DiscussionSPCBoone, Burt, Butler, Cass, Colfax, Cuming and 18 more92 min

Nearby

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