Alert archive / Missouri / Mesoscale Discussions in 2021
Mesoscale Discussion 769
The Storm Prediction Center issued this mesoscale discussion at May 27, 2021, 2:20 PM CDT for 22 counties in Illinois; 33 counties in Missouri. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- May 27, 2021, 2:20 PM CDT (19:20 UTC)
- Expired
- May 27, 2021, 3:45 PM CDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 214
All 55 counties
Alexander County, IL, Bond County, IL, Clay County, IL, Clinton County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Hamilton County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Perry County, IL, Pulaski County, IL, Randolph County, IL, Saint Clair County, IL, Union County, IL, Washington County, IL, Wayne County, IL, Williamson County, IL, Barry County, MO, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Christian County, MO, City of Saint Louis, MO, Crawford County, MO, Dent County, MO, Douglas County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Lawrence County, MO, Madison County, MO, McDonald County, MO, Mississippi County, MO, Newton County, MO, Oregon County, MO, Ozark County, MO, Perry 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, Stone County, MO, Taney County, MO, Texas County, MO, Washington County, MO, Wayne County, MO
The radar
The St Louis radar (KLSX), 98 km from the middle of the area, began a volume at 19:23 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
Springfield, MO (KSGF), launched 12:00Z, 7.3 hours before the alert went out and 303 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
- 295 J/kg
- Mixed-layer CIN
- -229 J/kg
- Mixed-layer LCL
- 964 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 69 m²/s²
- 0-3 km storm-relative helicity
- 160 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted.
274
ACUS11 KWNS 271920
SWOMCD
SPC MCD 271920
ILZ000-KYZ000-MOZ000-ARZ000-OKZ000-272045-
Mesoscale Discussion 0769
NWS Storm Prediction Center Norman OK
0220 PM CDT Thu May 27 2021
Areas affected...southern Illinois/southern Missouri
Concerning...Severe Thunderstorm Watch 214...
Valid 271920Z - 272045Z
The severe weather threat for Severe Thunderstorm Watch 214
continues.
SUMMARY...Local risk for damaging winds continues within the linear
band of storms crossing WW 214.
DISCUSSION...Latest radar loop shows a wavy band of storms extending
from east-central Illinois southwestward to southwestern Missouri,
with a couple of areas of enhanced/bowing storms. The convection
moving eastward across east-central Illinois has weakened, as it
encounters an airmass that becomes less unstable with eastward
extent. Meanwhile, the more moist/unstable environment indicated
over southern Illinois and into southeastern Missouri continues to
support vigorous storms -- capable of producing locally damaging
wind gusts.
..Goss.. 05/27/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...ILX...LSX...SGF...TSA...
LAT...LON 39148826 39228907 38409085 37219236 37079452 36499462
36669004 36808931 38118841 39148826SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 27, 11:04 AM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Christian, Clinton, Coles, Effingham and 18 more | 86 min |
| May 27, 11:26 AM CDT | Severe Thunderstorm Watch | SPC | Bond, Calhoun, Cass, Champaign, Christian, Clark and 42 more | 8 hr |
| May 27, 12:57 PM CDT | Mesoscale Discussion | SPC | Bond, Christian, Clinton, Effingham, Fayette, Jersey and 12 more | 93 min |
| May 27, 3:38 PM CDT | Mesoscale Discussion | SPC | Clay, Crawford, Edwards, Franklin, Hamilton, Jackson and 14 more | 67 min |
| May 27, 5:21 PM CDT | Mesoscale Discussion | SPC | Alexander, Gallatin, Hamilton, Hardin, Johnson, Massac and 6 more | 114 min |
| May 27, 12:51 AM CDT | Mesoscale Discussion | SPC | Barton, Buchanan, Platte | 84 min |
| May 27, 1:05 AM CDT | Severe Thunderstorm Watch | SPC | Bates, Buchanan, Cass, Clay, Jackson, Platte and 1 more | 7 hr |
| May 27, 5:28 AM CDT | Mesoscale Discussion | SPC | Cass, Jackson | 92 min |
| May 27, 1:36 PM CDT | Mesoscale Discussion | SPC | Andrew, Buchanan, Cass, Clay, Clinton, DeKalb and 2 more | 54 min |
| May 27, 2:06 PM CDT | Mesoscale Discussion | SPC | Butler, Dunklin, Oregon, Ripley | 84 min |
| May 27, 6:03 PM CDT | Mesoscale Discussion | SPC | Adair, Audrain, Boone, Buchanan, Caldwell, Carroll and 27 more | 87 min |
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.