Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 323

April 7, 202119 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 7, 2021, 1:30 PM CDT for 19 counties in Missouri. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Apr 7, 2021, 1:30 PM CDT (18:30 UTC)
Expired
Apr 7, 2021, 3:00 PM CDT
In force
90 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 74

Counties Camden County, MO, Christian County, MO, Cole County, MO, Dallas County, MO, Douglas County, MO, Greene County, MO, Hickory County, MO, Laclede County, MO, Miller County, MO, Moniteau County, MO, Morgan County, MO, Ozark County, MO, Polk County, MO, Pulaski County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Webster County, MO, Wright County, MO

The radar

The Springfield radar (KSGF), 61 km from the middle of the area, began a volume at 18:34 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

Springfield, MO (KSGF), launched 12:00Z, 6.5 hours before the alert went out and 112 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, Springfield, MO at 12:00Z on 2021-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 790 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 12:00Z on 2021-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 186 square meters per square second.19395878Sfc1 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
790 J/kg
Mixed-layer CIN
-275 J/kg
Mixed-layer LCL
767 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
186 m²/s²
0-3 km storm-relative helicity
223 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

052 
ACUS11 KWNS 071830
SWOMCD
SPC MCD 071830 
MOZ000-ARZ000-072000-

Mesoscale Discussion 0323
NWS Storm Prediction Center Norman OK
0130 PM CDT Wed Apr 07 2021

Areas affected...Parts of southwest through south central Missouri

Concerning...Severe Thunderstorm Watch 74...

Valid 071830Z - 072000Z

The severe weather threat for Severe Thunderstorm Watch 74
continues.

SUMMARY...An evolving line of thunderstorms is expected to continue
to intensify and organize through 2-4 PM CDT, and pose increasing
potential for damaging wind gusts, and perhaps a couple of
tornadoes, as it advances east-northeastward across the region.

DISCUSSION...A gradual increase in thunderstorm development is
ongoing within a narrow pre-cold frontal corridor now generally east
of the western Missouri state border area.  Latest objective
instability analyses suggest that strongest boundary-layer
destabilization is occurring along an axis, roughly, across Branson,
Springfield and the Lake of the Ozarks vicinity, into the
Columbia/Jefferson City areas.  Inflow of this air seems likely to
provide support for considerable further convective intensification
and upscale growth through 19-21Z.  In the presence of at least
35-40+ kt of southwesterly deep-layer mean shear, activity is
expected to take on increasing organization accompanied by the risk
for potentially damaging wind gusts.  This may include at least some
supercell structures which could pose a risk for a tornado or two,
particularly near/west of the West Plains vicinity, perhaps as far
north as Vichy, where clockwise-curved low-level hodographs are
forecast to become largest by around 4 PM CDT.

..Kerr.. 04/07/2021

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

ATTN...WFO...LSX...LZK...SGF...EAX...

LAT...LON   37709354 38269310 38699284 38789239 38539193 37219195
            36639228 36269288 36749360 37119370 37709354

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 7, 6:40 AM CDTMesoscale DiscussionSPCBarry, Camden, Cedar, Christian, Cole, Dade and 20 more2 hr
Apr 7, 10:18 AM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Boone, Buchanan and 42 more117 min
Apr 7, 12:02 PM CDTSevere Thunderstorm WatchSPCAdair, Audrain, Barry, Benton, Boone, Caldwell and 78 more7 hr
Apr 7, 2:22 PM CDTMesoscale DiscussionSPCHowell, Oregon, Ozark, Stone, Taney53 min
Apr 7, 3:13 PM CDTMesoscale DiscussionSPCAudrain, Boone, Callaway, Cole, Crawford, Dent and 21 more92 min
Apr 7, 3:40 PM CDTMesoscale DiscussionSPCOzark65 min
Apr 7, 5:04 PM CDTMesoscale DiscussionSPCAdair, Audrain, Callaway, Clark, Franklin, Gasconade and 17 more116 min
Apr 7, 5:12 PM CDTMesoscale DiscussionSPCDunklin, Pemiscot2 hr

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.