Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 1219

July 9, 202115 counties in Illinois; 24 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jul 9, 2021, 7:54 PM CDT for 15 counties in Illinois; 24 counties in Missouri. It was in force for 36 min.

The area

The outline as issued.

The facts

Issued
Jul 9, 2021, 7:54 PM CDT (00:54 UTC)
Expired
Jul 9, 2021, 8:30 PM CDT
In force
36 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch needed soon
Chance of a watch
95%
All 39 counties

Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Adair County, MO, Audrain County, MO, Chariton County, MO, Clark County, MO, Grundy County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Marion County, MO, Monroe County, MO, Montgomery County, MO, Pike County, MO, Putnam County, MO, Ralls County, MO, Randolph County, MO, Saint Charles County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 139 km from the middle of the area, began a volume at 00:54 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.9 hours before the alert went out and 234 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, Davenport, 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, Davenport, 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.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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1111 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
114 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

150 
ACUS11 KWNS 100054
SWOMCD
SPC MCD 100054 
ILZ000-MOZ000-IAZ000-100130-

Mesoscale Discussion 1219
NWS Storm Prediction Center Norman OK
0754 PM CDT Fri Jul 09 2021

Areas affected...northern into east-central MO...west-central IL

Concerning...Severe potential...Watch needed soon 

Valid 100054Z - 100130Z

Probability of Watch Issuance...95 percent

SUMMARY...A new severe thunderstorm watch will likely be issued for
much of the area in the short term.

DISCUSSION...An intense supercell over the past hour has moved from
southeast IA into west-central IL and is near the edge of severe
thunderstorm watch 358.  The risk for large hail will likely extend
southeastward into west-central IL over the next few hours as the
ongoing activity and additional storms form this evening.  It is
uncertain whether surface-based thunderstorm development will occur
farther west over northern MO in a very unstable airmass (3000+ J/kg
MLCAPE per the Springfield, MO and Topeka, KS 00z raobs).  If storms
develop, the risk for large to very large hail and severe gusts will
correspondingly increase.

..Smith/Thompson.. 07/10/2021

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

ATTN...WFO...ILX...LSX...DVN...EAX...

LAT...LON   40589273 40309050 40048971 39008935 38628996 38749126
            39179238 39749397 40279387 40589273

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, 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, 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.