Alert archive / Illinois / Mesoscale Discussions in 2019
Mesoscale Discussion 484
The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2019, 4:35 PM CDT for 28 counties in Illinois; 8 counties in Missouri. It was in force for 55 min.
The area
The outline as issued.
The facts
- Issued
- Apr 30, 2019, 4:35 PM CDT (21:35 UTC)
- Expired
- Apr 30, 2019, 5:30 PM CDT
- In force
- 55 min
- Issued by
- the Storm Prediction Center
All 36 counties
Bond County, IL, Calhoun County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jasper County, IL, Jersey County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Saint Clair County, IL, Shelby County, IL, Vermilion County, IL, City of Saint Louis, MO, Franklin County, MO, Jefferson County, MO, Lincoln County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO, Washington County, MO
The radar
The St Louis radar (KLSX), 93 km from the middle of the area, began a volume at 21:34 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
Lincoln, IL (KILX), launched 12:00Z, 9.6 hours before the alert went out and 151 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
- 914 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km storm-relative helicity
- 117 m²/s²
- 0-3 km storm-relative helicity
- 289 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
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 30, 12:39 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Christian, Clark, Clay, Clinton and 23 more | 2 hr |
| Apr 30, 1:00 PM CDT | Severe Thunderstorm Watch | SPC | Bond, Calhoun, Champaign, Christian, Clark, Clay and 26 more | 7 hr |
| Apr 30, 12:02 PM CDT | Tornado Watch | SPC | Barry, Barton, Camden, Cedar, Christian, Dade and 22 more | 13 hr |
| Apr 30, 3:26 PM CDT | Mesoscale Discussion | SPC | Barry, Jasper, Lawrence, McDonald, Newton | 2 hr |
| Apr 30, 6:00 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Cedar, Christian, Dade, Dallas and 21 more | 90 min |
Nearby
Mesoscale Discussions in Illinois, 2019Mesoscale Discussions in Missouri, 2019Every mesoscale discussion in 2019
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.