Alert archive / Illinois / Tornado Watches in 2026

Tornado Watch 131

April 17, 202656 counties in Illinois; 5 counties in Indiana; 22 counties in Missouri

The Storm Prediction Center issued this tornado watch at Apr 17, 2026, 3:31 PM CDT for 56 counties in Illinois; 5 counties in Indiana; 22 counties in Missouri. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: Apr 17, 2026, 3:31 PM CDT (20:31 UTC)
Expired: Apr 18, 2026, 12:00 AM CDT
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2.5 in
Strongest gust expected: 65 kt

All 83 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clinton County, IL, Coles County, IL, Cook County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, DuPage County, IL, Edgar County, IL, Fayette County, IL, Ford County, IL, Fulton County, IL, Greene County, IL, Grundy County, IL, Iroquois County, IL, Jersey County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Vermilion County, IL, Washington County, IL, Will County, IL, Woodford County, IL, Benton County, IN, Jasper County, IN, Lake County, IN, Newton County, IN, Porter County, IN, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Shelby County, MO, Warren County, MO

The radar

The Lincoln radar (KILX), 26 km from the middle of the area, began a volume at 20:34 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.

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: 80%
One or more gusts of 65 knots or more: 40%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 40%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

84 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Apr 17, 3:39 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Greene, Jersey, Pike	49 min
Apr 17, 3:40 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Monroe, Ralls	37 min
Apr 17, 3:45 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Pike	32 min
Apr 17, 4:04 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis	23 min
Apr 17, 4:11 PM CDT	Severe Thunderstorm Warning	ILX	Cass, Morgan, Scott	34 min
Apr 17, 4:11 PM CDT	Severe Thunderstorm Warning	LSX	Jersey, Macoupin, Madison	25 min
Apr 17, 4:22 PM CDT	Severe Thunderstorm Warning	LSX	Brown, Pike	38 min
Apr 17, 4:45 PM CDT	Severe Thunderstorm Warning	ILX	Cass, Mason, Morgan, Schuyler	45 min
Apr 17, 5:03 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Fulton	42 min
Apr 17, 5:03 PM CDT	Tornado Warning	LSX	Knox, Lewis, Shelby	42 min
Apr 17, 5:30 PM CDT	Severe Thunderstorm Warning	ILX	Fulton, Knox, Peoria	45 min
Apr 17, 5:38 PM CDT	Tornado Warning	LSX	Adams	52 min
Apr 17, 5:51 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Knox, Shelby	54 min
Apr 17, 5:58 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Knox, Peoria, Stark	47 min
Apr 17, 5:58 PM CDT	Tornado Warning	LSX	Knox	32 min
Apr 17, 6:13 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Adams	47 min
Apr 17, 6:23 PM CDT	Tornado Warning	LSX	Adams	41 min
Apr 17, 6:38 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Knox	37 min
Apr 17, 6:46 PM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis, Marion, Monroe, Ralls, Shelby	44 min
Apr 17, 6:47 PM CDT	Tornado Warning	ILX	Knox	43 min
Apr 17, 6:53 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Schuyler	52 min
Apr 17, 6:53 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Adams	52 min
Apr 17, 7:05 PM CDT	Tornado Warning	ILX	Knox, Stark	25 min
Apr 17, 7:13 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Marshall, Peoria, Stark	47 min
Apr 17, 7:16 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Boone, DeKalb, Kane, McHenry	74 min
Apr 17, 7:21 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Fulton, Knox	54 min
Apr 17, 7:21 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Adams, Brown, Pike	54 min
Apr 17, 7:26 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Cass, Fulton, Mason, Morgan, Schuyler, Scott	34 min
Apr 17, 7:30 PM CDT	Tornado Warning	ILX	Marshall, Stark	30 min
Apr 17, 7:36 PM CDT	Tornado Warning	ILX	Fulton	24 min
Apr 17, 7:42 PM CDT	Tornado Warning	LSX	Boone, Callaway, Cole, Moniteau	48 min
Apr 17, 7:50 PM CDT	Tornado Warning	ILX	Knox, Marshall, Peoria, Stark	40 min
Apr 17, 7:56 PM CDT	Tornado Warning	ILX	Fulton, Mason	34 min
Apr 17, 7:57 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Boone, Callaway, Cole, Moniteau, Osage	63 min
Apr 17, 7:58 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Cass, Fulton, Knox, Marshall, Mason, Menard and 5 more	49 min
Apr 17, 8:01 PM CDT	Tornado Warning	ILX	Marshall, Peoria, Stark	29 min
Apr 17, 8:02 PM CDT	Tornado Warning	ILX	Fulton, Peoria, Tazewell	28 min
Apr 17, 8:04 PM CDT	Tornado Warning	LOT	Lake	56 min
Apr 17, 8:10 PM CDT	Tornado Warning	ILX	Mason, Tazewell	35 min
Apr 17, 8:12 PM CDT	Flash Flood Warning	LOT	Boone, Lake, McHenry	6 hr
Apr 17, 8:12 PM CDT	Severe Thunderstorm Warning	LSX	Brown, Pike	17 min
Apr 17, 8:16 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Cass, DeWitt, Logan, McLean, Mason, Menard and 2 more	59 min
Apr 17, 8:17 PM CDT	Tornado Warning	LSX	Boone, Callaway, Cole, Moniteau	43 min
Apr 17, 8:18 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Cook, Lake	72 min
Apr 17, 8:19 PM CDT	Tornado Warning	ILX	Marshall, Peoria, Tazewell, Woodford	41 min
Apr 17, 8:20 PM CDT	Tornado Warning Tornado observed	ILX	Logan, McLean, Mason, Tazewell	40 min
Apr 17, 8:28 PM CDT	Tornado Warning	ILX	Logan, Mason, Menard	32 min
Apr 17, 8:29 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Kane, McHenry	31 min
Apr 17, 8:30 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	McLean, Marshall, Tazewell, Woodford	45 min
Apr 17, 8:30 PM CDT	Tornado Warning	LSX	Callaway, Cole, Osage	45 min
Apr 17, 8:36 PM CDT	Tornado Warning	LOT	Lake, McHenry	39 min
Apr 17, 8:39 PM CDT	Tornado Warning Tornado observed	ILX	McLean, Tazewell, Woodford	36 min
Apr 17, 8:43 PM CDT	Tornado Warning	ILX	McLean, Tazewell, Woodford	47 min
Apr 17, 8:45 PM CDT	Tornado Warning	LSX	Audrain, Callaway, Montgomery	45 min
Apr 17, 8:46 PM CDT	Tornado Warning	LOT	LaSalle, Livingston	47 min
Apr 17, 8:47 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	DuPage, Grundy, Kane, Kendall, Will	73 min
Apr 17, 8:53 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Christian, Logan, Macon, Sangamon	52 min
Apr 17, 8:54 PM CDT	Tornado Warning	ILX	Marshall, Woodford	21 min
Apr 17, 8:57 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Franklin, Gasconade, Montgomery, Osage, Warren	48 min
Apr 17, 9:00 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	DeWitt, McLean, Piatt	45 min
Apr 17, 9:01 PM CDT	Tornado Warning	ILX	McLean	44 min
Apr 17, 9:05 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Ford, Iroquois, Kankakee, Livingston, Will	70 min
Apr 17, 9:08 PM CDT	Tornado Warning Tornado observed	ILX	DeWitt, Logan, McLean, Macon, Piatt	37 min
Apr 17, 9:15 PM CDT	Tornado Warning	LOT	Ford, Iroquois, Livingston	60 min
Apr 17, 9:23 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Will	82 min
Apr 17, 9:23 PM CDT	Tornado Warning	LOT	Grundy, Kankakee, Kendall, Livingston, Will	52 min
Apr 17, 9:23 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Montgomery, Pike	52 min
Apr 17, 9:27 PM CDT	Severe Thunderstorm Warning	ILX	Macon, Piatt	48 min
Apr 17, 9:29 PM CDT	Tornado Warning	LSX	Lincoln, Montgomery, Warren	31 min
Apr 17, 9:36 PM CDT	Tornado Warning Tornado observed	LSX	Warren	20 min
Apr 17, 9:37 PM CDT	Severe Thunderstorm Warning	ILX	Champaign	38 min
Apr 17, 9:42 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Piatt	18 min
Apr 17, 9:42 PM CDT	Tornado Warning	ILX	Champaign, Piatt	48 min
Apr 17, 9:42 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun	48 min
Apr 17, 9:46 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Douglas, Moultrie, Piatt	44 min
Apr 17, 9:46 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Iroquois, Kankakee	59 min
Apr 17, 9:50 PM CDT	Tornado Warning	LSX	Calhoun	25 min
Apr 17, 10:01 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Benton, Jasper, Lake, Newton, Porter	74 min
Apr 17, 10:11 PM CDT	Severe Thunderstorm Warning	ILX	Vermilion	49 min
Apr 17, 10:14 PM CDT	Severe Thunderstorm Warning	LSX	Jersey, Madison	31 min
Apr 17, 10:15 PM CDT	Severe Thunderstorm Warning	ILX	Champaign	19 min
Apr 17, 10:15 PM CDT	Tornado Warning	LOT	Kankakee	17 min
Apr 17, 10:26 PM CDT	Tornado Warning	LSX	Jersey	19 min
Apr 17, 10:31 PM CDT	Tornado Warning	LOT	Cook, Will	29 min

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, 8.5 hours before the alert went out and 51 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 84 J/kg
Mixed-layer CIN: -150 J/kg
Mixed-layer LCL: 1053 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 65 m²/s²
0-3 km storm-relative helicity: 164 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 17, 11:48 AM CDT	Mesoscale Discussion	SPC	Carroll, Jo Daviess, Ogle, Stephenson, Winnebago	2 hr
Apr 17, 12:40 PM CDT	Tornado Watch	SPC	Boone, Bureau, Carroll, DeKalb, Hancock, Henderson and 14 more	9 hr
Apr 17, 2:05 PM CDT	Mesoscale Discussion	SPC	Jo Daviess	55 min
Apr 17, 3:04 PM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Cass, Christian and 20 more	56 min
Apr 17, 4:42 PM CDT	Mesoscale Discussion	SPC	Boone, Lake, McHenry, Winnebago	2 hr
Apr 17, 6:25 PM CDT	Mesoscale Discussion	SPC	Adams, Boone, Bureau, Carroll, DeKalb, Fulton and 22 more	2 hr
Apr 17, 12:42 PM CDT	Mesoscale Discussion	SPC	Andrew, Bates, Buchanan, Caldwell, Cass, Clay and 10 more	3 hr
Apr 17, 1:40 PM CDT	Tornado Watch	SPC	Adair, Andrew, Barton, Bates, Benton, Buchanan and 40 more	7 hr
Apr 17, 3:31 PM CDT	Mesoscale Discussion	SPC	Adair, Andrew, Bates, Buchanan, Caldwell, Carroll and 23 more	89 min
Apr 17, 5:10 PM CDT	Mesoscale Discussion	SPC	Audrain, Barton, Bates, Benton, Boone, Callaway and 28 more	2 hr

Nearby

Tornado Watches in Illinois, 2026 Tornado Watches in Missouri, 2026 Tornado Watches in Indiana, 2026 Every tornado watch in 2026

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.