Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 1234

July 10, 20218 counties in Illinois; 9 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jul 10, 2021, 3:09 AM CDT for 8 counties in Illinois; 9 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 10, 2021, 3:09 AM CDT (08:09 UTC)
Expired
Jul 10, 2021, 5:15 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 364

Counties Alexander County, IL, Franklin County, IL, Jackson County, IL, Johnson County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Williamson County, IL, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Perry County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO

The radar

The Paducah radar (KPAH), 108 km from the middle of the area, began a volume at 08:10 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 00:00Z, 8.2 hours before the alert went out and 280 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, Little Rock, AR at 00:00Z on 2021-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1372 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, Little Rock, AR at 00:00Z on 2021-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 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
1372 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
1621 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
7 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted.

393 
ACUS11 KWNS 100809
SWOMCD
SPC MCD 100809 
ILZ000-MOZ000-ARZ000-101015-

Mesoscale Discussion 1234
NWS Storm Prediction Center Norman OK
0309 AM CDT Sat Jul 10 2021

Areas affected...southeastern Missouri/southern Illinois

Concerning...Severe Thunderstorm Watch 364...

Valid 100809Z - 101015Z

The severe weather threat for Severe Thunderstorm Watch 364
continues.

SUMMARY...Local risk for gusty/damaging winds continues across WW
364.

DISCUSSION...Latest radar loop shows near-continuous line of strong
storms moving southeastward across southeastern Missouri and
adjacent southern Illinois at around 30 kt.  Ahead of the storms, an
airmass featuring 1000 to 1500 J/kg mixed-layer CAPE persists, which
should allow convection to persist as it advances steadily
southeastward.  While the latest PAH WSR-88D VWP data shows only
moderate (AOB 30 kt) flow through the lower half of the troposphere,
a few stronger gusts remain possible given the still-organized
nature of the convective band.

..Goss.. 07/10/2021

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

ATTN...WFO...PAH...MEG...LSX...SGF...

LAT...LON   37329078 37559010 38118912 38168874 37828843 37128915
            36499019 36519095 37099113 37329078

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 9, 7:08 PM CDTSevere Thunderstorm WatchSPCHancock, Henderson, McDonough, Warren3 hr
Jul 9, 7:54 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Greene, Jersey and 9 more36 min
Jul 9, 8:18 PM CDTTornado WatchSPCAdams, Brown, Calhoun, Cass, Greene, Jersey and 9 more6 hr
Jul 9, 10:26 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Greene, Jersey and 7 more64 min
Jul 10, 1:01 AM CDTMesoscale DiscussionSPCClinton, Jackson, Monroe, Perry, Randolph, Saint Clair and 3 more59 min
Jul 10, 1:36 AM CDTSevere Thunderstorm WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Jackson and 10 more4 hr
Jul 10, 1:25 PM CDTMesoscale DiscussionSPCAlexander, Clay, Clinton, Edwards, Franklin, Gallatin and 22 more2 hr
Jul 10, 2:01 PM CDTSevere Thunderstorm WatchSPCAlexander, Bond, Clay, Clinton, Crawford, Edwards and 28 more8 hr
Jul 10, 3:09 PM CDTMesoscale DiscussionSPCCass, Champaign, DeWitt, Douglas, Ford, Logan and 8 more96 min
Jul 10, 5:33 PM CDTMesoscale DiscussionSPCClay, Edwards, Franklin, Gallatin, Hamilton, Hardin and 10 more87 min
Jul 9, 9:12 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Clay, Clinton and 8 more2 hr
Jul 9, 9:58 PM CDTSevere Thunderstorm WatchSPCAndrew, Atchison, Buchanan, Caldwell, Carroll, Chariton and 22 more7 hr
Jul 10, 1:21 AM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Clay, Clinton and 11 more84 min
Jul 10, 2:57 AM CDTMesoscale DiscussionSPCBates, Caldwell, Carroll, Cass, Chariton, Clay and 20 more93 min
Jul 10, 5:04 AM CDTMesoscale DiscussionSPCButler, Carter, Ripley, Stoddard56 min
Jul 10, 11:37 AM CDTMesoscale DiscussionSPCBarry, Christian, Douglas, Howell, Laclede, McDonald and 9 more83 min
Jul 10, 1:20 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Holt, Nodaway115 min
Jul 10, 2:17 PM CDTMesoscale DiscussionSPCBarry, Barton, Jasper, McDonald, Newton, Vernon118 min
Jul 10, 2:18 PM CDTSevere Thunderstorm WatchSPCAndrew, Atchison, Buchanan, Clay, Clinton, DeKalb and 6 more7 hr
Jul 10, 3:02 PM CDTSevere Thunderstorm WatchSPCBarry, Barton, Camden, Cedar, Christian, Dade and 26 more8 hr
Jul 10, 3:44 PM CDTMesoscale DiscussionSPCAtchison, Holt91 min
Jul 10, 5:27 PM CDTMesoscale DiscussionSPCAndrew, Buchanan, Caldwell, Carroll, Clay, Clinton and 13 more2 hr

Nearby

Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Illinois, 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.