Alert archive / Illinois / Tornado Watches in 2025

Tornado Watch 304

May 20, 202537 counties in Illinois; 8 counties in Indiana

The Storm Prediction Center issued this tornado watch at May 20, 2025, 1:42 PM CDT for 37 counties in Illinois; 8 counties in Indiana. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 20, 2025, 1:42 PM CDT (18:42 UTC)
Expired: May 20, 2025, 8:00 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 45 counties

Bureau County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Ford County, IL, Fulton County, IL, Henry County, IL, Iroquois County, IL, Knox County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Putnam County, IL, Sangamon County, IL, Schuyler County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Vermilion County, IL, Warren County, IL, Woodford County, IL, Benton County, IN, Fountain County, IN, Montgomery County, IN, Parke County, IN, Tippecanoe County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN

The radar

The Lincoln radar (KILX), 77 km from the middle of the area, began a volume at 18:41 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: 20%
Ten or more severe wind reports: 40%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 60%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 20, 1:43 PM CDT	Severe Thunderstorm Warning	DVN	Henry, Mercer, Rock Island	62 min
May 20, 2:03 PM CDT	Tornado Warning	DVN	Henry, Mercer, Rock Island	29 min
May 20, 2:03 PM CDT	Tornado Warning	ILX	Menard, Sangamon	30 min
May 20, 2:13 PM CDT	Tornado Warning	ILX	Sangamon	33 min
May 20, 2:24 PM CDT	Tornado Warning	DVN	Henry	51 min
May 20, 2:30 PM CDT	Severe Thunderstorm Warning	ILX	Knox, Marshall, Peoria, Stark, Tazewell, Woodford	45 min
May 20, 2:31 PM CDT	Severe Thunderstorm Warning	ILX	Logan, Menard, Sangamon	44 min
May 20, 2:36 PM CDT	Tornado Warning Tornado observed	ILX	Logan, Sangamon	39 min
May 20, 2:37 PM CDT	Tornado Warning	DVN	Bureau, Henry	38 min
May 20, 2:56 PM CDT	Severe Thunderstorm Warning	DVN	Bureau, Putnam	47 min
May 20, 3:11 PM CDT	Tornado Warning	ILX	DeWitt, Logan, Macon, Sangamon	49 min
May 20, 3:14 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Vermilion	31 min
May 20, 3:19 PM CDT	Severe Thunderstorm Warning	LOT	Ford	41 min
May 20, 3:50 PM CDT	Tornado Warning	ILX	DeWitt, McLean	12 min
May 20, 3:53 PM CDT	Severe Thunderstorm Warning	ILX	DeWitt, McLean	37 min
May 20, 3:54 PM CDT	Tornado Warning	ILX	DeWitt, Macon, Piatt	36 min
May 20, 4:06 PM CDT	Tornado Warning	LOT	Ford, Iroquois	39 min
May 20, 4:12 PM CDT	Severe Thunderstorm Warning	ILX	Champaign	33 min
May 20, 4:14 PM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois, Livingston	76 min
May 20, 4:24 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Vermilion	51 min
May 20, 4:27 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Champaign, Piatt	48 min
May 20, 4:33 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, McLean	12 min
May 20, 4:38 PM CDT	Tornado Warning	LOT	Iroquois	27 min
May 20, 4:47 PM CDT	Tornado Warning	ILX	Champaign, Vermilion	43 min
May 20, 5:10 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ILX	Champaign, Vermilion	65 min
May 20, 5:26 PM CDT	Tornado Warning Tornado observed	ILX	Vermilion	34 min
May 20, 5:31 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Vermilion	23 min
May 20, 5:43 PM CDT	Tornado Warning	IND	Fountain, Warren	19 min
May 20, 6:07 PM CDT	Severe Thunderstorm Warning	ILX	Champaign, Vermilion	38 min
May 20, 6:24 PM CDT	Tornado Warning	IND	Fountain	36 min
May 20, 6:41 PM CDT	Tornado Warning	IND	Fountain, Montgomery	34 min
May 20, 7:12 PM CDT	Severe Thunderstorm Warning	IND	Montgomery	21 min
May 20, 7:20 PM CDT	Severe Thunderstorm Warning	ILX	Edgar, Vermilion	40 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, 6.7 hours before the alert went out and 43 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: 562 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 634 m²/s²
0-3 km storm-relative helicity: 684 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 19, 7:36 PM CDT	Mesoscale Discussion	SPC	Calhoun, Jersey, Monroe, Randolph, Saint Clair	2 hr
May 19, 8:26 PM CDT	Tornado Watch	SPC	Alexander, Bond, Calhoun, Clinton, Fayette, Franklin and 17 more	7 hr
May 19, 10:42 PM CDT	Mesoscale Discussion	SPC	Bond, Calhoun, Clinton, Jackson, Jersey, Madison and 5 more	2 hr
May 20, 1:07 AM CDT	Mesoscale Discussion	SPC	Alexander, Bond, Clay, Clinton, Crawford, Edwards and 27 more	83 min
May 20, 2:15 AM CDT	Tornado Watch	SPC	Clay, Edwards, Gallatin, Hamilton, Hardin, Lawrence and 7 more	4 hr
May 20, 1:09 PM CDT	Tornado Watch	SPC	Alexander, Johnson, Massac, Pope, Pulaski, Union	8 hr
May 20, 1:44 PM CDT	Mesoscale Discussion	SPC	Champaign, Christian, Clark, Coles, Crawford, Cumberland and 15 more	106 min
May 20, 2:36 PM CDT	Tornado Watch	SPC	Hardin	8 hr
May 20, 5:51 PM CDT	Mesoscale Discussion	SPC	Vermilion	54 min

Nearby

Tornado Watches in Illinois, 2025 Tornado Watches in Indiana, 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.