Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 1830

October 11, 202113 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Oct 11, 2021, 5:00 AM CDT for 13 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Oct 11, 2021, 5:00 AM CDT (10:00 UTC)
Expired
Oct 11, 2021, 7:00 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%

Counties Cedar County, MO, Christian County, MO, Dade County, MO, Dallas County, MO, Greene County, MO, Hickory County, MO, Lawrence County, MO, Polk County, MO, St. Clair County, MO, Stone County, MO, Taney County, MO, Vernon County, MO, Webster County, MO

The radar

The Springfield radar (KSGF), 30 km from the middle of the area, began a volume at 10:01 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 00:00Z, 10.0 hours before the alert went out and 60 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 00:00Z on 2021-10-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Springfield, MO at 00:00Z on 2021-10-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2067 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

593 
ACUS11 KWNS 111000
SWOMCD
SPC MCD 111000 
MOZ000-111200-

Mesoscale Discussion 1830
NWS Storm Prediction Center Norman OK
0500 AM CDT Mon Oct 11 2021

Areas affected...Portions of southwestern MO

Concerning...Severe potential...Watch unlikely 

Valid 111000Z - 111200Z

Probability of Watch Issuance...20 percent

SUMMARY...A threat for a brief tornado and isolated strong/gusty
winds may continue for a couple more hours early this morning. Watch
issuance is unlikely at this time.

DISCUSSION...A low-topped line of convection has recently moved into
parts of southwestern MO. A strong, 50+ kt low-level jet is present
over this region. This low-level jet and a pronounced southwesterly
mid-level jet associated with a shortwave trough ejecting from the
southern Plains across the Ozarks are supporting strong low-level
and deep-layer shear. One of the cells embedded within the
low-topped line recently acquired low-level rotation, and a
corresponding CC minimum in dual pol radar data from KSGF. Although
the low-level shear remains rather favorable for continued storm
organization in the short term across southwestern MO, the
thermodynamic environment is much more marginal. A leading wave of
convection has already moved across this region, with surface
temperatures generally in the upper 60s. Weak boundary-layer
instability should continue to limit updraft intensities,
particularly as these storms move eastward and away from a narrow,
maximized corridor of this instability characterized by MLCAPE
around 500 J/kg. While a brief tornado and strong/gusty winds may
continue to be a threat for the next couple of hours, the overall
severe threat will probably remain too isolated to justify new watch
issuance early this morning.

..Gleason/Edwards.. 10/11/2021

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

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

LAT...LON   37629426 37919437 38269393 38269310 37769260 37089279
            36539306 36539377 36829380 37309403 37629426

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 10, 7:19 PM CDTMesoscale DiscussionSPCBates86 min
Oct 10, 9:24 PM CDTTornado WatchSPCBarry, Jasper, Lawrence, McDonald, Newton5 hr
Oct 10, 11:32 PM CDTMesoscale DiscussionSPCJasper, McDonald, Newton118 min
Oct 11, 1:26 AM CDTMesoscale DiscussionSPCBarry, Dade, Greene, Jasper, Lawrence, McDonald and 2 more64 min
Oct 11, 9:06 AM CDTMesoscale DiscussionSPCAudrain, Callaway, Franklin, Gasconade, Jefferson, Lincoln and 11 more2 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.