Alert archive / Missouri / Mesoscale Discussions in 2021
Mesoscale Discussion 1130
The Storm Prediction Center issued this mesoscale discussion at Jun 30, 2021, 12:22 PM CDT for 4 states. It was in force for 113 min.
The area
The outline as issued.
The facts
- Issued
- Jun 30, 2021, 12:22 PM CDT (17:22 UTC)
- Expired
- Jun 30, 2021, 2:15 PM CDT
- In force
- 113 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 61 counties
Alexander County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Massac County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saline County, IL, Union County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Posey County, IN, Vanderburgh County, IN, Ballard County, KY, Caldwell County, KY, Carlisle County, KY, Crittenden County, KY, Henderson County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Crawford County, MO, Dent County, MO, Douglas County, MO, Howell County, MO, Iron County, MO, Laclede County, MO, Madison County, MO, Mississippi County, MO, Oregon County, MO, Ozark County, MO, Perry County, MO, Phelps County, MO, Pulaski County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Texas County, MO, Washington County, MO, Wayne County, MO, Wright County, MO
The radar
The Paducah radar (KPAH), 118 km from the middle of the area, began a volume at 17:25 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
Little Rock, AR (KLZK), launched 12:00Z, 5.4 hours before the alert went out and 306 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.
- Mixed-layer CAPE
- 72 J/kg
- Mixed-layer CIN
- -72 J/kg
- Mixed-layer LCL
- 1091 m above ground
- 0-6 km bulk shear
- 3 kt
- 0-1 km storm-relative helicity
- -46 m²/s²
- 0-3 km storm-relative helicity
- -13 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
471
ACUS11 KWNS 301722
SWOMCD
SPC MCD 301722
KYZ000-INZ000-ILZ000-MOZ000-301915-
Mesoscale Discussion 1130
NWS Storm Prediction Center Norman OK
1222 PM CDT Wed Jun 30 2021
Areas affected...Southeast Missouri into the lower Ohio River Valley
Concerning...Severe potential...Watch unlikely
Valid 301722Z - 301915Z
Probability of Watch Issuance...5 percent
SUMMARY...Diurnal thunderstorms are developing in an environment
conducive for isolated damaging winds and perhaps a brief hail
threat. This threat will remain isolated in nature, and a watch is
not expected.
DISCUSSION...Recent GOES visible imagery and composite reflectivity
data show deepening cumulus and weak convection developing across
the higher terrain of the MO Ozarks. This activity is being driven
by diurnal heating south of a weak frontal zone where mostly clear
skies are allowing temperatures to warm into the upper 80s.
Satellite imagery suggests most of this activity is not yet fully
mature, but continued warming through the afternoon will aid in
further destabilization and gradual intensification as convection
drifts east/southeast towards the lower OH river valley. Moderate
instability (near 2000 J/kg MLCAPE expected by mid-afternoon)
combined with steepening low-level lapse rates may support a few
downdrafts capable of damaging wind gusts. A brief hail threat may
evolve with the initial development of any stronger updraft, but
weak mid/upper-level flow will limit updraft longevity and the
attendant hail threat. While storm coverage may increase through the
afternoon as low-level parcels hit their convective temperatures,
strong to severe storms should remain somewhat sporadic and mitigate
the need for a watch.
..Moore/Thompson.. 06/30/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...ILX...LSX...SGF...
LAT...LON 37619269 37919222 38188994 38338950 38538901 38688849
38508794 38148750 37688732 37228775 36908817 36798874
36658956 36589186 36649272 36899297 37619269Nearby
Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Illinois, 2021Mesoscale Discussions in Kentucky, 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.