Alert archive / Kansas / Mesoscale Discussions in 2021

Mesoscale Discussion 924

June 11, 20219 counties in Kansas

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2021, 1:55 PM CDT for 9 counties in Kansas. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Jun 11, 2021, 1:55 PM CDT (18:55 UTC)
Expired
Jun 11, 2021, 3:30 PM CDT
In force
95 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 259

Counties Douglas County, KS, Franklin County, KS, Jefferson County, KS, Johnson County, KS, Leavenworth County, KS, Miami County, KS, Osage County, KS, Shawnee County, KS, Wyandotte County, KS

The radar

The Pleasant Hill radar (KEAX), 82 km from the middle of the area, began a volume at 18:59 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 12:00Z, 6.9 hours before the alert went out and 39 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°0°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.

410 
ACUS11 KWNS 111855
SWOMCD
SPC MCD 111855 
MOZ000-KSZ000-112030-

Mesoscale Discussion 0924
NWS Storm Prediction Center Norman OK
0155 PM CDT Fri Jun 11 2021

Areas affected...for parts of northeast and eastern KS

Concerning...Severe Thunderstorm Watch 259...

Valid 111855Z - 112030Z

The severe weather threat for Severe Thunderstorm Watch 259
continues.

SUMMARY...The risk for severe gusts (60-85 mph) is highest over this
corridor thru 4pm.

DISCUSSION...Radar mosaic shows a severe cluster of storms over
northeast KS moving to the southeast at 25 kt.  A Union Pacific
observation site recently measured an 83 mph gust at 1:38pm.  The
airmass between Topeka and Kansas City continues to destabilize
early this afternoon.  Modifying the 11am Topeka, KS raob shows for
current surface conditions yields 4000 J/kg SBCAPE for lower 70s
dewpoints.  Farther south, greater buoyancy is expected over
southeast KS where a reservoir of mid-upper 70s dewpoints resides. 
The Topeka WSR-88D VAD shows southeasterly surface winds veering to
20 kt southwesterly at 3 km AGL to 35 kt west-southwesterly at 6 km
AGL.  As a result, the wind profile coupled with the buoyancy is
very supportive for organized severe storms this afternoon.  Early
afternoon trends with the thunderstorm complex show continued
preference for deep/intense updrafts (50 kft echo tops) on the
west-southwest flank of the complex.  With the lowest 100 mb mean
mixing ratios sampled/inferred by the Topeka raob/surface
observations, intense downbursts will probably become more common
this afternoon as this complex moves south.  Peak wind gusts ranging
from 60-85 mph are expected through 4pm.

..Smith.. 06/11/2021

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

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

LAT...LON   39299535 39569496 39109455 38689453 38359485 38359545
            38599585 39169585 39299535

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, 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

Nearby

Mesoscale 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.