Alert archive / Illinois / Tornado Watches in 2024
Tornado Watch 154
The Storm Prediction Center issued this tornado watch at Apr 27, 2024, 9:41 PM CDT for 29 counties in Illinois; 22 counties in Missouri. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 27, 2024, 9:41 PM CDT (02:41 UTC)
- Expired
- Apr 28, 2024, 4:00 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 51 counties
Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, DeWitt County, IL, Fulton County, IL, Greene County, IL, Jersey County, IL, Knox County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Stark County, IL, Tazewell County, IL, Woodford County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Lincoln County, MO, Maries County, MO, Marion County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO
The radar
The Lincoln radar (KILX), 70 km from the middle of the area, began a volume at 02:41 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 10:23 PM CDT | Tornado Warning | SGF | Morgan | 37 min |
| Apr 27, 10:25 PM CDT | Flash Flood Warning | ILX | DeWitt | 110 min |
| Apr 27, 10:41 PM CDT | Tornado Warning | LSX | Moniteau | 49 min |
| Apr 27, 11:58 PM CDT | Flash Flood Warning | ILX | Marshall, Tazewell, Woodford | 6 hr |
| Apr 28, 1:39 AM CDT | Flash Flood Warning | ILX | Fulton, Knox, Marshall, Peoria, Tazewell, Woodford | 4 hr |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 2.7 hours before the alert went out and 129 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
- 738 J/kg
- Mixed-layer CIN
- -35 J/kg
- Mixed-layer LCL
- 786 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 138 m²/s²
- 0-3 km storm-relative helicity
- 190 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 3.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 7:58 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, DeKalb, DuPage, Fulton, Grundy and 20 more | 62 min |
| Apr 27, 9:15 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Fulton, Greene and 15 more | 60 min |
| Apr 28, 1:54 AM CDT | Mesoscale Discussion | SPC | Calhoun, Greene, Jersey, Macoupin, Madison | 66 min |
| Apr 27, 7:11 PM CDT | Mesoscale Discussion | SPC | Adair, Clark, Grundy, Knox, Putnam, Schuyler and 2 more | 64 min |
| Apr 27, 8:25 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Benton, Carroll, Cass, Cedar and 15 more | 95 min |
| Apr 27, 11:42 PM CDT | Tornado Watch | SPC | Barry, Barton, Benton, Cedar, Christian, Dade and 18 more | 5 hr |
| Apr 28, 3:38 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Dade, Jasper, Lawrence, McDonald and 1 more | 2 hr |
| Apr 28, 5:15 PM CDT | Tornado Watch | SPC | Barry, Douglas, McDonald, Newton, Ozark, Stone and 3 more | 6 hr |
| Apr 28, 6:50 PM CDT | Mesoscale Discussion | SPC | Barry, McDonald | 55 min |
Nearby
Tornado Watches in Illinois, 2024Tornado Watches in Missouri, 2024Every tornado watch in 2024
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.