Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 1042

June 20, 20218 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2021, 9:56 PM CDT for 8 counties in Missouri. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Jun 20, 2021, 9:56 PM CDT (02:56 UTC)
Expired
Jun 20, 2021, 11:00 PM CDT
In force
64 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 294

Counties Bates County, MO, Cass County, MO, Cooper County, MO, Henry County, MO, Johnson County, MO, Lafayette County, MO, Pettis County, MO, Saline County, MO

The radar

The Pleasant Hill radar (KEAX), 58 km from the middle of the area, began a volume at 02:59 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 00:00Z, 2.9 hours before the alert went out and 178 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 00:00Z on 2021-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2316 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2021-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 square meters per square second.193958Sfc1 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
2316 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
2228 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
0.0
Supercell composite
8.8

Open this sounding in Storm Lab

The text

As transmitted.

270 
ACUS11 KWNS 210257
SWOMCD
SPC MCD 210256 
MOZ000-KSZ000-210400-

Mesoscale Discussion 1042
NWS Storm Prediction Center Norman OK
0956 PM CDT Sun Jun 20 2021

Areas affected...North-central Missouri and far eastern Kansas.

Concerning...Severe Thunderstorm Watch 294...

Valid 210256Z - 210400Z

The severe weather threat for Severe Thunderstorm Watch 294
continues.

SUMMARY...A few severe storms with a threat for strong wind gusts
will remain possible across the far southern fringe of WW294 through
the 0400z expiration time.

DISCUSSION...As of 0240z, RADAR data showed a loosely organized band
of storms stretching from near Kansas City into north-central
Missouri. Storm coverage has increased likely as a result of
strengthening low-level warm advection with the nocturnal low-level
jet. Flow associated with the jet will remain largely parallel to
the ongoing band of storms suggesting slower forward propagating
speeds and additional development focused along the southern flank.
Mostly non-severe gusts have been observed over the last 40 minutes,
but storms will likely remain capable of isolated damaging gusts as
they exit the southern portions of WW294 over the next hour.
Additional cellular development to the west across far eastern
Kansas may grow upscale and continue to the east posing a risk for
isolated gusts and or small hail after 04z. While convective
coverage is forecast to increase, the threat for severe weather
should gradually abate through 0400z as the boundary layer separates
and inhibition increases.

..Lyons.. 06/21/2021

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

ATTN...WFO...SGF...EAX...

LAT...LON   39239375 39359313 39279281 38989262 38769268 38719281
            38639323 38399371 38179432 38249461 38509469 38889464
            39239375

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 8:10 PM CDTSevere Thunderstorm WatchSPCAudrain, Boone, Callaway, Knox, Lewis, Lincoln and 7 more5 hr
Jun 20, 9:54 PM CDTMesoscale DiscussionSPCMonroe, Ralls66 min
Jun 21, 11:35 AM CDTMesoscale DiscussionSPCDunklin, Pemiscot85 min

Nearby

Mesoscale 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.