Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 1224

July 9, 202113 counties in Illinois; 27 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jul 9, 2021, 10:26 PM CDT for 13 counties in Illinois; 27 counties in Missouri. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Jul 9, 2021, 10:26 PM CDT (03:26 UTC)
Expired
Jul 9, 2021, 11:30 PM CDT
In force
64 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 359
All 40 counties

Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Menard County, IL, Morgan County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Adair County, MO, Audrain County, MO, Boone County, MO, Callaway County, MO, Chariton County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Franklin County, MO, Gasconade County, MO, Howard County, MO, Lincoln County, MO, Linn County, MO, Macon County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Saint Charles County, MO, Saint Louis County, MO, Shelby County, MO, Sullivan County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 104 km from the middle of the area, began a volume at 03:28 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

Lincoln, IL (KILX), launched 00:00Z, 3.4 hours before the alert went out and 256 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, Lincoln, IL at 00:00Z on 2021-07-10Temperature 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, Lincoln, IL at 00:00Z on 2021-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1282 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

977 
ACUS11 KWNS 100326
SWOMCD
SPC MCD 100326 
ILZ000-MOZ000-100430-

Mesoscale Discussion 1224
NWS Storm Prediction Center Norman OK
1026 PM CDT Fri Jul 09 2021

Areas affected...Northeast and central Missouri

Concerning...Tornado Watch 359...

Valid 100326Z - 100430Z

The severe weather threat for Tornado Watch 359 continues.

SUMMARY...Potential for severe/significant winds is increase in
parts of central/eastern Missouri as a broad mesocyclone continues
to develop and move south/southeastward.

DISCUSSION...A broad mesocyclone is evident on KLSX radar velocity
imagery roughly centered in Ralls County, MO. As this feature
continues southward into a moderate to strongly unstable
environment, the potential for significant wind gusts will increase
in portions of central/eastern Missouri. The 00Z SGF sounding
sampled 8+ C/km lapse rates with MLCAPE around 3000 J/kg. Strong
downdrafts will continue to be favored in this environment,
particularly as effective shear remains at 35-40 kts. Though storm
mode has become linear, KLSX VAD profile continues to show enough
low-level veering to support a threat for QLCS circulations and
brief tornadoes.

..Wendt.. 07/10/2021

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

ATTN...WFO...ILX...LSX...SGF...EAX...

LAT...LON   40469325 40129236 39909145 40189083 40238984 39758944
            38688999 38309040 38009143 38319227 38669285 40469325

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 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, 3:09 AM CDTMesoscale DiscussionSPCAlexander, Franklin, Jackson, Johnson, Pulaski, Saline and 2 more2 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.