Alert archive / Missouri / Mesoscale Discussions in 2020
Mesoscale Discussion 490
The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2020, 6:32 PM CDT for 35 counties in Illinois; 56 counties in Missouri. It was in force for 118 min.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2020, 6:32 PM CDT (23:32 UTC)
- Expired
- Apr 28, 2020, 8:30 PM CDT
- In force
- 118 min
- Issued by
- the Storm Prediction Center
All 91 counties
Bond County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clinton County, IL, DeWitt County, IL, Douglas County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jackson County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Perry County, IL, Piatt County, IL, Pike County, IL, Randolph County, IL, Saint Clair County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Washington County, IL, Audrain County, MO, Barton County, MO, Benton County, MO, Bollinger County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Carter County, MO, Cedar County, MO, Christian County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Dade County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Hickory County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Laclede County, MO, Lawrence County, MO, Lincoln County, MO, Madison County, MO, Maries County, MO, Miller County, MO, Moniteau County, MO, Montgomery County, MO, Morgan County, MO, Oregon County, MO, Osage County, MO, Ozark County, MO, Perry County, MO, Phelps County, MO, Pike County, MO, Polk County, MO, Pulaski County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Shannon County, MO, St. Clair County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Warren County, MO, Washington County, MO, Wayne County, MO, Webster County, MO, Wright County, MO
The radar
The St Louis radar (KLSX), 61 km from the middle of the area, began a volume at 23:34 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
Springfield, MO (KSGF), launched 12:00Z, 11.5 hours before the alert went out and 279 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
- 55 J/kg
- Mixed-layer CIN
- -231 J/kg
- Mixed-layer LCL
- 1021 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 369 m²/s²
- 0-3 km storm-relative helicity
- 342 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.1
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 3:33 PM CDT | Mesoscale Discussion | SPC | Adams, Bond, Brown, Bureau, Calhoun, Cass and 41 more | 87 min |
| Apr 28, 3:51 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Bond, Brown, Calhoun, Cass, Christian and 37 more | 7 hr |
| Apr 28, 4:51 PM CDT | Mesoscale Discussion | SPC | Cook, DeKalb, DuPage, Grundy, Kane, Kankakee and 4 more | 114 min |
| Apr 28, 6:41 PM CDT | Mesoscale Discussion | SPC | Alexander, Clay, Edwards, Franklin, Hamilton, Jackson and 12 more | 64 min |
| Apr 28, 1:55 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Cedar, Dade, Greene, Jasper and 6 more | 3 hr |
| Apr 28, 3:18 PM CDT | Tornado Watch | SPC | Barry, Barton, Jasper, Lawrence, McDonald, Newton and 2 more | 8 hr |
| Apr 28, 6:15 PM CDT | Mesoscale Discussion | SPC | Barry, McDonald, Newton | 2 hr |
Nearby
Mesoscale Discussions in Missouri, 2020Mesoscale Discussions in Illinois, 2020Every mesoscale discussion in 2020
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.