Alert archive / Illinois / Tornado Watches in 2025

Tornado Watch 155

April 20, 202558 counties in Illinois; 10 counties in Iowa; 34 counties in Missouri

The Storm Prediction Center issued this tornado watch at Apr 20, 2025, 3:41 PM CDT for 58 counties in Illinois; 10 counties in Iowa; 34 counties in Missouri. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Apr 20, 2025, 3:41 PM CDT (20:41 UTC)
Expired: Apr 20, 2025, 11:00 PM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 102 counties

Des Moines County, IA, Henry County, IA, Jefferson County, IA, Keokuk County, IA, Lee County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Adams County, IL, Alexander County, IL, Bond County, IL, Brown County, IL, Bureau County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, Clinton County, IL, DeWitt County, IL, Fayette County, IL, Franklin County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jackson County, IL, Jefferson County, IL, Jersey County, IL, Johnson County, IL, Knox County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Mercer County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Perry County, IL, Piatt County, IL, Pike County, IL, Pulaski County, IL, Putnam County, IL, Randolph County, IL, Rock Island County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Union County, IL, Warren County, IL, Washington County, IL, Whiteside County, IL, Williamson County, IL, Woodford County, IL, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Clark County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Madison County, MO, Marion County, MO, Mississippi County, MO, Montgomery County, MO, New Madrid County, MO, Perry County, MO, Pike County, MO, Reynolds County, MO, Ripley County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scotland County, MO, Scott County, MO, Shelby County, MO, Stoddard County, MO, Warren County, MO, Washington County, MO, Wayne County, MO

The radar

The St Louis radar (KLSX), 79 km from the middle of the area, began a volume at 20:41 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: 50%
One or more EF2 to EF5 tornadoes: 30%
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

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

Issued	Product	Office	Counties	Lasted
Apr 20, 5:25 PM CDT	Severe Thunderstorm Warning	DVN	Henry, Jefferson, Lee, Van Buren, Washington	65 min
Apr 20, 5:30 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Audrain, Boone, Callaway, Monroe, Montgomery, Ralls	45 min
Apr 20, 5:34 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Monroe, Shelby	41 min
Apr 20, 5:44 PM CDT	Tornado Warning	LSX	Callaway, Montgomery	46 min
Apr 20, 5:46 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Franklin, Gasconade, Warren	44 min
Apr 20, 6:03 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Pike, Ralls	42 min
Apr 20, 6:07 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Crawford, Franklin, Gasconade, Iron, Reynolds, Washington	53 min
Apr 20, 6:07 PM CDT	Tornado Warning	LSX	Lincoln, Pike	38 min
Apr 20, 6:11 PM CDT	Tornado Warning	LSX	Pike	49 min
Apr 20, 6:15 PM CDT	Severe Thunderstorm Warning	LSX	Adams	60 min
Apr 20, 6:20 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Franklin, Lincoln, Montgomery, Saint Charles, Saint Louis, Warren	40 min
Apr 20, 6:27 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Brown, Calhoun, Pike	63 min
Apr 20, 6:32 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, Henderson	43 min
Apr 20, 6:40 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Pike	20 min
Apr 20, 6:45 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Cass, Fulton, Mason, Morgan, Schuyler, Scott	45 min
Apr 20, 6:49 PM CDT	Tornado Warning	LSX	Adams	41 min
Apr 20, 6:56 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Greene, Jersey, Madison	64 min
Apr 20, 6:56 PM CDT	Tornado Warning	LSX	Brown, Pike	28 min
Apr 20, 6:58 PM CDT	Severe Thunderstorm Warning	LSX	Monroe	62 min
Apr 20, 7:00 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, McDonough	60 min
Apr 20, 7:06 PM CDT	Tornado Warning	PAH	Carter, Ripley	39 min
Apr 20, 7:13 PM CDT	Tornado Warning	LSX	Iron, Madison, Reynolds, Saint Francois, Washington	47 min
Apr 20, 7:14 PM CDT	Severe Thunderstorm Warning	DVN	Henderson, Mercer, Warren	61 min
Apr 20, 7:14 PM CDT	Severe Thunderstorm Warning	LSX	Adams	16 min
Apr 20, 7:22 PM CDT	Tornado Warning	ILX	Schuyler	23 min
Apr 20, 7:25 PM CDT	Severe Thunderstorm Warning	DVN	Mercer, Rock Island	65 min
Apr 20, 7:28 PM CDT	Tornado Warning	LSX	Jefferson, Sainte Genevieve, Saint Francois, Washington	37 min
Apr 20, 7:29 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Cass, Christian, Fulton, Mason, Menard, Sangamon and 2 more	7 min
Apr 20, 7:33 PM CDT	Severe Thunderstorm Warning	DVN	Hancock, Henderson, McDonough, Warren	42 min
Apr 20, 7:33 PM CDT	Tornado Warning	DVN	Henderson, Mercer	42 min
Apr 20, 7:33 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Cass, Fulton, Mason, Menard, Morgan, Sangamon and 2 more	27 min
Apr 20, 7:37 PM CDT	Tornado Warning	DVN	Hancock, Henderson, McDonough, Warren	23 min
Apr 20, 7:43 PM CDT	Severe Thunderstorm Warning	LSX	Macoupin	47 min
Apr 20, 7:53 PM CDT	Severe Thunderstorm Warning	LSX	Monroe, Randolph, Saint Clair	52 min
Apr 20, 7:55 PM CDT	Severe Thunderstorm Warning	DVN	McDonough, Mercer, Warren	65 min
Apr 20, 7:56 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Cass, Fulton, Mason, Menard, Morgan, Sangamon and 1 more	34 min
Apr 20, 7:56 PM CDT	Tornado Warning	LSX	Randolph	49 min
Apr 20, 7:57 PM CDT	Tornado Warning	DVN	Warren	23 min
Apr 20, 7:59 PM CDT	Severe Thunderstorm Warning	ILX	Fulton, Knox, Mason, Schuyler	31 min
Apr 20, 7:59 PM CDT	Severe Thunderstorm Warning	PAH	Wayne	31 min
Apr 20, 8:00 PM CDT	Tornado Warning	DVN	Mercer, Rock Island	32 min
Apr 20, 8:03 PM CDT	Tornado Warning	LSX	Monroe, Saint Clair	42 min
Apr 20, 8:08 PM CDT	Severe Thunderstorm Warning	DVN	Rock Island	67 min
Apr 20, 8:18 PM CDT	Tornado Warning	PAH	Wayne	12 min
Apr 20, 8:19 PM CDT	Tornado Warning	LSX	Madison	41 min
Apr 20, 8:25 PM CDT	Severe Thunderstorm Warning	ILX	Christian, Logan, Mason, Menard, Peoria, Sangamon and 1 more	35 min
Apr 20, 8:28 PM CDT	Severe Thunderstorm Warning	ILX	Fulton, Knox, Marshall, Peoria, Stark, Tazewell and 1 more	32 min
Apr 20, 8:31 PM CDT	Severe Thunderstorm Warning	DVN	Henry	59 min
Apr 20, 8:32 PM CDT	Tornado Warning	LSX	Randolph, Saint Clair, Washington	43 min
Apr 20, 8:36 PM CDT	Tornado Warning	DVN	Henry, Mercer	39 min
Apr 20, 8:36 PM CDT	Tornado Warning	ILX	Tazewell	24 min
Apr 20, 8:38 PM CDT	Tornado Warning	LSX	Bond, Clinton, Madison, Saint Clair	38 min
Apr 20, 8:40 PM CDT	Tornado Warning	PAH	Bollinger, Perry	35 min
Apr 20, 8:42 PM CDT	Tornado Warning	PAH	Perry	18 min
Apr 20, 8:52 PM CDT	Tornado Warning	DVN	Henry	34 min
Apr 20, 8:56 PM CDT	Severe Thunderstorm Warning	ILX	McLean, Marshall, Peoria, Stark, Tazewell, Woodford	15 min
Apr 20, 8:59 PM CDT	Tornado Warning	ILX	Tazewell, Woodford	17 min
Apr 20, 9:06 PM CDT	Tornado Warning Tornado observed	DVN	Henry, Rock Island, Whiteside	24 min
Apr 20, 9:07 PM CDT	Tornado Warning	PAH	Jackson	38 min
Apr 20, 9:12 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Marion, Washington	35 min
Apr 20, 9:12 PM CDT	Severe Thunderstorm Warning	PAH	Bollinger, Stoddard, Wayne	33 min
Apr 20, 9:14 PM CDT	Tornado Warning	DVN	Bureau, Henry, Whiteside	31 min
Apr 20, 9:19 PM CDT	Severe Thunderstorm Warning	PAH	Jefferson	26 min
Apr 20, 9:36 PM CDT	Tornado Warning	PAH	Jackson	26 min
Apr 20, 9:39 PM CDT	Severe Thunderstorm Warning	PAH	Cape Girardeau	39 min
Apr 20, 9:54 PM CDT	Severe Thunderstorm Warning	PAH	Franklin, Jackson, Williamson	36 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, 8.7 hours before the alert went out and 176 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1064 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 20, 2:20 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calhoun, Cass, Fulton, Greene and 19 more	115 min
Apr 20, 5:40 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calhoun, Cass, Fulton, Greene and 16 more	95 min
Apr 20, 1:22 AM CDT	Mesoscale Discussion	SPC	Barry, McDonald	53 min
Apr 20, 2:26 AM CDT	Severe Thunderstorm Watch	SPC	Barry, Christian, Dade, Dallas, Douglas, Greene and 10 more	5 hr
Apr 20, 3:54 AM CDT	Mesoscale Discussion	SPC	Barry, Christian, Dallas, Douglas, Greene, Laclede and 7 more	2 hr
Apr 20, 12:03 PM CDT	Tornado Watch	SPC	Audrain, Barry, Barton, Bates, Benton, Boone and 45 more	9 hr
Apr 20, 12:17 PM CDT	Mesoscale Discussion	SPC	Barry, Benton, Camden, Cedar, Christian, Cole and 24 more	118 min
Apr 20, 2:23 PM CDT	Mesoscale Discussion	SPC	Audrain, Barton, Benton, Boone, Callaway, Camden and 19 more	97 min
Apr 20, 2:46 PM CDT	Mesoscale Discussion	SPC	Barry, Christian, Douglas, Greene, Howell, Lawrence and 7 more	89 min
Apr 20, 5:39 PM CDT	Tornado Watch	SPC	Dunklin, Pemiscot	6 hr

Nearby

Tornado Watches in Illinois, 2025 Tornado Watches in Missouri, 2025 Tornado Watches in Iowa, 2025 Every tornado watch in 2025

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.