Alert archive / Missouri / Mesoscale Discussions in 2021
Mesoscale Discussion 1228
The Storm Prediction Center issued this mesoscale discussion at Jul 10, 2021, 1:01 AM CDT for 9 counties in Illinois; 29 counties in Missouri. It was in force for 59 min.
The area
The outline as issued.
The facts
- Issued
- Jul 10, 2021, 1:01 AM CDT (06:01 UTC)
- Expired
- Jul 10, 2021, 2:00 AM CDT
- In force
- 59 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 359
All 38 counties
Clinton County, IL, Jackson County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Union County, IL, Washington County, IL, Williamson County, IL, Bollinger County, MO, Boone County, MO, Callaway County, MO, Cape Girardeau County, MO, Chariton County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Crawford County, MO, Dent County, MO, Franklin County, MO, Gasconade County, MO, Howard County, MO, Iron County, MO, Jefferson County, MO, Linn County, MO, Madison County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Osage County, MO, Perry County, MO, Phelps County, MO, Randolph County, MO, Reynolds County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Sullivan County, MO, Washington County, MO
The radar
The St Louis radar (KLSX), 39 km from the middle of the area, began a volume at 06:03 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
Lincoln, IL (KILX), launched 00:00Z, 6.0 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.
- 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
The text
As transmitted.
624
ACUS11 KWNS 100601
SWOMCD
SPC MCD 100601
ILZ000-MOZ000-100700-
Mesoscale Discussion 1228
NWS Storm Prediction Center Norman OK
0101 AM CDT Sat Jul 10 2021
Areas affected...eastern Missouri into southwestern Illinois
Concerning...Tornado Watch 359...
Valid 100601Z - 100700Z
The severe weather threat for Tornado Watch 359 continues.
SUMMARY...Strong/locally severe storms continue. With the watch
scheduled to expire at 07Z, local watch extension -- or new WW
issuance, may be needed.
DISCUSSION...Latest radar shows an arcing band of strong/severe
storms moving south-southeastward across eastern Missouri and
adjacent southwestern Illinois, with a 70 MPH gust recently noted at
STL. The convection is advancing at 40 to 45 kt, and at this rate
of advance, storms will clear southern portions of the current watch
near the 10/07Z scheduled expiration time. With a moist/unstable
airmass ahead of the convection, and mid-level flow at least
modestly supportive of continued organization to the convection, a
new WW may be needed soon, extending into the PAH (Paducah KY) CWA.
Farther to the northwest, isolated, strong/severe storms continue to
regenerate and shift southeastward -- with this regeneration
occurring where a 30 kt west-southwesterly low-level jet is
impinging on the northwest-to-southeast front/outflow boundary over
eastern Missouri. Again, with the watch set to expire at 10/07z,
this portion of the area may also need to be included in any new WW
issuance.
..Goss.. 07/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...LSX...SGF...EAX...
LAT...LON 38609053 38798969 38598940 37758879 37188966 37209096
37339166 38549272 40049342 40299315 38649162 38609053SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 9, 7:08 PM CDT | Severe Thunderstorm Watch | SPC | Hancock, Henderson, McDonough, Warren | 3 hr |
| Jul 9, 7:54 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Greene, Jersey and 9 more | 36 min |
| Jul 9, 8:18 PM CDT | Tornado Watch | SPC | Adams, Brown, Calhoun, Cass, Greene, Jersey and 9 more | 6 hr |
| Jul 9, 10:26 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Greene, Jersey and 7 more | 64 min |
| Jul 10, 1:36 AM CDT | Severe Thunderstorm Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Jackson and 10 more | 4 hr |
| Jul 10, 3:09 AM CDT | Mesoscale Discussion | SPC | Alexander, Franklin, Jackson, Johnson, Pulaski, Saline and 2 more | 2 hr |
| Jul 10, 1:25 PM CDT | Mesoscale Discussion | SPC | Alexander, Clay, Clinton, Edwards, Franklin, Gallatin and 22 more | 2 hr |
| Jul 10, 2:01 PM CDT | Severe Thunderstorm Watch | SPC | Alexander, Bond, Clay, Clinton, Crawford, Edwards and 28 more | 8 hr |
| Jul 10, 3:09 PM CDT | Mesoscale Discussion | SPC | Cass, Champaign, DeWitt, Douglas, Ford, Logan and 8 more | 96 min |
| Jul 10, 5:33 PM CDT | Mesoscale Discussion | SPC | Clay, Edwards, Franklin, Gallatin, Hamilton, Hardin and 10 more | 87 min |
| Jul 9, 9:12 PM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Buchanan, Caldwell, Clay, Clinton and 8 more | 2 hr |
| Jul 9, 9:58 PM CDT | Severe Thunderstorm Watch | SPC | Andrew, Atchison, Buchanan, Caldwell, Carroll, Chariton and 22 more | 7 hr |
| Jul 10, 1:21 AM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Buchanan, Caldwell, Clay, Clinton and 11 more | 84 min |
| Jul 10, 2:57 AM CDT | Mesoscale Discussion | SPC | Bates, Caldwell, Carroll, Cass, Chariton, Clay and 20 more | 93 min |
| Jul 10, 5:04 AM CDT | Mesoscale Discussion | SPC | Butler, Carter, Ripley, Stoddard | 56 min |
| Jul 10, 11:37 AM CDT | Mesoscale Discussion | SPC | Barry, Christian, Douglas, Howell, Laclede, McDonald and 9 more | 83 min |
| Jul 10, 1:20 PM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Holt, Nodaway | 115 min |
| Jul 10, 2:17 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Jasper, McDonald, Newton, Vernon | 118 min |
| Jul 10, 2:18 PM CDT | Severe Thunderstorm Watch | SPC | Andrew, Atchison, Buchanan, Clay, Clinton, DeKalb and 6 more | 7 hr |
| Jul 10, 3:02 PM CDT | Severe Thunderstorm Watch | SPC | Barry, Barton, Camden, Cedar, Christian, Dade and 26 more | 8 hr |
| Jul 10, 3:44 PM CDT | Mesoscale Discussion | SPC | Atchison, Holt | 91 min |
| Jul 10, 5:27 PM CDT | Mesoscale Discussion | SPC | Andrew, Buchanan, Caldwell, Carroll, Clay, Clinton and 13 more | 2 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.