Alert archive / Missouri / Mesoscale Discussions in 2021
Mesoscale Discussion 765
The Storm Prediction Center issued this mesoscale discussion at May 27, 2021, 12:57 PM CDT for 18 counties in Illinois; 20 counties in Missouri. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- May 27, 2021, 12:57 PM CDT (17:57 UTC)
- Expired
- May 27, 2021, 2:30 PM CDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 214
All 38 counties
Bond County, IL, Christian County, IL, Clinton County, IL, Effingham County, IL, Fayette County, IL, Jersey County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Moultrie County, IL, Saint Clair County, IL, Sangamon County, IL, Shelby County, IL, Washington County, IL, Barry County, MO, Christian County, MO, City of Saint Louis, MO, Crawford County, MO, Dallas County, MO, Dent County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Jefferson County, MO, Laclede County, MO, Lawrence County, MO, Maries County, MO, Phelps County, MO, Pulaski County, MO, Saint Charles County, MO, Saint Louis County, MO, Washington County, MO, Webster County, MO, Wright County, MO
The radar
The St Louis radar (KLSX), 31 km from the middle of the area, began a volume at 17:57 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 12:00Z, 6.0 hours before the alert went out and 271 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
- 1679 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 130 m²/s²
- 0-3 km storm-relative helicity
- 150 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
028
ACUS11 KWNS 271758
SWOMCD
SPC MCD 271757
ILZ000-MOZ000-271930-
Mesoscale Discussion 0765
NWS Storm Prediction Center Norman OK
1257 PM CDT Thu May 27 2021
Areas affected...central Illinois into southern and eastern Missouri
Concerning...Severe Thunderstorm Watch 214...
Valid 271757Z - 271930Z
The severe weather threat for Severe Thunderstorm Watch 214
continues.
SUMMARY...Severe risk -- primarily in the form of damaging wind
gusts -- is ongoing across portions of WW 214.
DISCUSSION...Latest radar loop indicates a broken band of storms
that has evolved from central Illinois southwestward to southwestern
Missouri. While any stronger storms within this area may produce
locally gusty winds and/or hail, two particular areas where damaging
wind potential may be enhanced in the short term are across portions
of central Illinois, and just east of the I-44 corridor east of SGF.
In Illinois, a bowing band of storms is moving eastward at around 40
kt, and will affect areas between St. Louis and Decatur, where wind
gusts in excess of 60 MPH may occur.
In southwestern Missouri, a small bowing segment within the larger
convective band along the I-44 corridor is moving across portions of
Laclede and Webster counties, toward Wright County. Wind gusts in
excess of 60 MPH may occur as the cluster surges east-southeastward.
..Goss.. 05/27/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...ILX...LSX...SGF...
LAT...LON 40198971 39878828 38618858 37649134 36519417 37279396
37869293 39069041 40198971SPC 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, 2:20 PM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Clay, Clinton, Effingham, Fayette and 16 more | 85 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.