Alert archive / Illinois / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 174
The Storm Prediction Center issued this severe thunderstorm watch at Apr 29, 2017, 3:57 PM CDT for 44 counties in Illinois; Ballard County, McCracken County, Kentucky; 11 counties in Missouri. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 29, 2017, 3:57 PM CDT (20:57 UTC)
- Expired
- Apr 29, 2017, 10:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 57 counties
Alexander County, IL, Bond 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, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Massac County, IL, Monroe County, IL, Montgomery County, IL, Moultrie County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Shelby County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Ballard County, KY, McCracken County, KY, Bollinger County, MO, Cape Girardeau County, MO, Carter County, MO, Iron County, MO, Madison County, MO, Perry County, MO, Reynolds County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Wayne County, MO
The radar
The St Louis radar (KLSX), 127 km from the middle of the area, began a volume at 20:57 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
25 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 29, 4:03 PM CDT | Severe Thunderstorm Warning | LSX | Jersey, Macoupin, Madison, Montgomery | 42 min |
| Apr 29, 4:42 PM CDT | Severe Thunderstorm Warning | LSX | Bond, Fayette, Macoupin, Madison, Montgomery | 48 min |
| Apr 29, 4:46 PM CDT | Severe Thunderstorm Warning | ILX | Christian, Macon, Shelby | 44 min |
| Apr 29, 5:16 PM CDT | Flash Flood Warning | ILX | Christian, Sangamon | 6 hr |
| Apr 29, 5:20 PM CDT | Flash Flood Warning | LSX | Calhoun, Greene, Jersey, Macoupin, Montgomery | 8 hr |
| Apr 29, 5:26 PM CDT | Severe Thunderstorm Warning | ILX | Christian, Macon, Moultrie, Piatt, Shelby | 49 min |
| Apr 29, 5:29 PM CDT | Severe Thunderstorm Warning | LSX | Bond, Clinton, Fayette, Marion, Montgomery | 61 min |
| Apr 29, 5:50 PM CDT | Tornado Warning | ILX | Macon, Moultrie, Shelby | 25 min |
| Apr 29, 6:14 PM CDT | Severe Thunderstorm Warning | ILX | Champaign, Clark, Clay, Coles, Cumberland, DeWitt and 11 more | 46 min |
| Apr 29, 6:22 PM CDT | Flash Flood Warning | ILX | Coles, Cumberland, Effingham, Jasper, Macon, Moultrie and 1 more | 6 hr |
| Apr 29, 6:43 PM CDT | Flash Flood Warning | ILX | Champaign, Douglas, Edgar, Piatt, Vermilion | 6 hr |
| Apr 29, 6:49 PM CDT | Flash Flood Warning | PAH | Carter | 13 hr |
| Apr 29, 6:50 PM CDT | Flash Flood Warning | ILX | Clark, Crawford | 6 hr |
| Apr 29, 6:56 PM CDT | Severe Thunderstorm Warning | ILX | Champaign, Coles, Douglas, Edgar, Vermilion | 49 min |
| Apr 29, 6:57 PM CDT | Flash Flood Warning | ILX | Clay, Lawrence, Richland | 3 hr |
| Apr 29, 7:03 PM CDT | Severe Thunderstorm Warning | ILX | Clark, Clay, Coles, Crawford, Cumberland, Edgar and 3 more | 42 min |
| Apr 29, 7:04 PM CDT | Flash Flood Warning | PAH | Franklin, Jackson, Johnson, Perry, Union, Williamson | 12 hr |
| Apr 29, 7:10 PM CDT | Severe Thunderstorm Warning | PAH | Carter, Ripley | 23 min |
| Apr 29, 7:32 PM CDT | Severe Thunderstorm Warning | PAH | Butler, Carter, Wayne | 28 min |
| Apr 29, 7:44 PM CDT | Severe Thunderstorm Warning | ILX | Clark, Crawford, Edgar, Jasper, Lawrence, Richland | 46 min |
| Apr 29, 7:46 PM CDT | Severe Thunderstorm Warning | ILX | Edgar, Vermilion | 14 min |
| Apr 29, 8:02 PM CDT | Flash Flood Warning | PAH | Alexander | 12 hr |
| Apr 29, 8:09 PM CDT | Flash Flood Warning | LSX | Bond, Fayette, Montgomery | 5 hr |
| Apr 29, 8:31 PM CDT | Flash Flood Warning | PAH | Gallatin, Hamilton, Hardin, Pope, Saline, White | 4 hr |
| Apr 29, 9:50 PM CDT | Flash Flood Warning | PAH | Alexander, Johnson, Pulaski, Union | 3 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 12:00Z, 9.0 hours before the alert went out and 190 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
- 776 m above ground
- 0-6 km bulk shear
- 61 kt
- 0-1 km storm-relative helicity
- 242 m²/s²
- 0-3 km storm-relative helicity
- 568 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 10:01 PM CDT | Severe Thunderstorm Watch | SPC | Alexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 7 more | 9 hr |
| Apr 28, 11:55 PM CDT | Mesoscale Discussion | SPC | Alexander, Franklin, Gallatin, Hardin, Jackson, Johnson and 6 more | 95 min |
| Apr 29, 3:39 AM CDT | Mesoscale Discussion | SPC | Alexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 8 more | 96 min |
| Apr 29, 12:50 PM CDT | Mesoscale Discussion | SPC | Monroe, Randolph, Saint Clair | 85 min |
| Apr 29, 3:28 PM CDT | Mesoscale Discussion | SPC | Bond, Clay, Clinton, Crawford, Edwards, Effingham and 20 more | 2 hr |
| Apr 29, 6:30 PM CDT | Mesoscale Discussion | SPC | Alexander, Clark, Clay, Coles, Crawford, Cumberland and 25 more | 60 min |
| Apr 28, 7:10 PM CDT | Severe Thunderstorm Watch | SPC | Bartholomew, Brown, Dearborn, Decatur, Fayette, Franklin and 8 more | 6 hr |
| Apr 28, 8:27 PM CDT | Tornado Watch | SPC | Clark, Crawford, Dubois, Floyd, Gibson, Harrison and 10 more | 5 hr |
| Apr 28, 10:19 PM CDT | Mesoscale Discussion | SPC | Clark, Crawford, Daviess, Dearborn, Dubois, Floyd and 18 more | 116 min |
| Apr 29, 12:50 AM CDT | Mesoscale Discussion | SPC | Clark, Crawford, Dubois, Floyd, Gibson, Harrison and 11 more | 85 min |
| Apr 29, 6:23 AM CDT | Mesoscale Discussion | SPC | Clark, Dearborn, Floyd, Harrison, Jackson, Jefferson and 6 more | 3 hr |
Nearby
Severe Thunderstorm Watches in Illinois, 2017Severe Thunderstorm Watches in Missouri, 2017Severe Thunderstorm Watches in Kentucky, 2017Every severe thunderstorm watch in 2017
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.