Alert archive / Illinois / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 367, NWS Lincoln, IL
NWS Lincoln, IL issued this severe thunderstorm warning at Aug 15, 2026, 3:43 AM CDT for 7 counties in Illinois. It was in force for 62 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 15, 2026, 3:43 AM CDT (08:43 UTC)
- Expired
- Aug 15, 2026, 4:45 AM CDT
- In force
- 62 min
- Issued by
- NWS Lincoln, IL
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Cass County, IL, Fulton County, IL, Mason County, IL, Menard County, IL, Morgan County, IL, Schuyler County, IL, Tazewell County, IL
The radar
The Lincoln radar (KILX), 95 km from the middle of the area, began a volume at 08:46 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.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 8.7 hours before the alert went out and 157 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
- 1237 J/kg
- Mixed-layer CIN
- -137 J/kg
- Mixed-layer LCL
- 748 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 167 m²/s²
- 0-3 km storm-relative helicity
- 197 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.2
The text
As transmitted.
989
WUUS53 KILX 150843
SVRILX
ILC017-057-125-129-137-169-179-150945-
/O.NEW.KILX.SV.W.0367.260815T0843Z-260815T0945Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Lincoln IL
343 AM CDT Sat Aug 15 2026
The National Weather Service in Lincoln has issued a
* Severe Thunderstorm Warning for...
Western Menard County in central Illinois...
Fulton County in west central Illinois...
Southwestern Tazewell County in central Illinois...
Cass County in west central Illinois...
Schuyler County in west central Illinois...
Mason County in central Illinois...
Northern Morgan County in west central Illinois...
* Until 445 AM CDT.
* At 343 AM CDT, severe thunderstorms were located along a line
extending from near Lewistown to near Rushville, moving east at 40
mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Severe thunderstorms will be near...
Lewistown, St. David, and Browning around 350 AM CDT.
Havana and Bath around 355 AM CDT.
Other locations in the path of these severe thunderstorms include
Chandlerville, Manito, Kilbourne, Easton, Green Valley and Mason
City.
This includes Interstate 72 between mile markers 71 and 73.
This also includes Anderson Lake State Fish and Wildlife Area, Jim
Edgar Panther Creek Fish and Wildlife Area, Rice Lake State Fish and
Wildlife Area, Sand Ridge State Forest, Spring Lake State Fish and
Wildlife Area, and Sanganois State Fish and Wildlife Area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4028 9066 4028 9045 4058 9044 4047 8948
3990 8997 3990 8999 3987 8999 3973 9011
3982 9057 3987 9059 3997 9051 3999 9052
3998 9060 4003 9061 4002 9063 4005 9068
4008 9067 4008 9070 4011 9071 4011 9077
TIME...MOT...LOC 0843Z 278DEG 33KT 4045 9017 4009 9049
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Copple3 follow-up statements
142
WWUS53 KILX 150916
SVSILX
Severe Weather Statement
National Weather Service Lincoln IL
416 AM CDT Sat Aug 15 2026
ILC017-057-125-129-137-169-179-150945-
/O.CON.KILX.SV.W.0367.000000T0000Z-260815T0945Z/
Menard-Fulton-Tazewell-Cass-Schuyler-Mason-Morgan-
416 AM CDT Sat Aug 15 2026
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 AM CDT
FOR WESTERN MENARD...SOUTHERN FULTON...SOUTHWESTERN TAZEWELL...
CASS...SOUTHEASTERN SCHUYLER...MASON AND NORTHERN MORGAN COUNTIES...
At 416 AM CDT, severe thunderstorms were located along a line
extending from Manito to near Chandlerville, moving east at 40 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
These severe storms will be near...
Manito, Green Valley, Easton, and Kilbourne around 420 AM CDT.
Mason City around 430 AM CDT.
Other locations impacted by these severe thunderstorms include
Bryant, Prentice, Topeka, Liverpool, Frederick, Bluff City, Chatauqua
Park, Concord, Atterberry, and Snicarte.
This also includes Anderson Lake State Fish and Wildlife Area, Jim
Edgar Panther Creek Fish and Wildlife Area, Sand Ridge State Forest,
and Sanganois State Fish and Wildlife Area.
This includes Interstate 72 between mile markers 71 and 73.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3990 8997 3990 8999 3987 8999 3973 9011
3982 9057 3987 9059 3997 9051 3999 9052
4048 9022 4042 8952
TIME...MOT...LOC 0916Z 278DEG 33KT 4041 8978 4005 9011
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Copple191
WWUS53 KILX 150930
SVSILX
Severe Weather Statement
National Weather Service Lincoln IL
430 AM CDT Sat Aug 15 2026
ILC057-169-150940-
/O.CAN.KILX.SV.W.0367.000000T0000Z-260815T0945Z/
Fulton-Schuyler-
430 AM CDT Sat Aug 15 2026
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN FULTON AND
SOUTHEASTERN SCHUYLER COUNTIES IS CANCELLED...
The storms which prompted the warning have moved out of the warned
area. Therefore, the warning has been cancelled.
&&
LAT...LON 3990 8997 3990 8999 3987 8999 3973 9011
3979 9044 4045 8990 4042 8952
TIME...MOT...LOC 0930Z 270DEG 33KT 4039 8963 4003 8996
$$
ILC017-125-129-137-179-150945-
/O.CON.KILX.SV.W.0367.000000T0000Z-260815T0945Z/
Menard-Tazewell-Cass-Mason-Morgan-
430 AM CDT Sat Aug 15 2026
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 AM CDT
FOR WESTERN MENARD...SOUTHWESTERN TAZEWELL...EASTERN CASS...MASON AND
NORTHEASTERN MORGAN COUNTIES...
At 430 AM CDT, severe thunderstorms were located along a line
extending from Green Valley to near Petersburg, moving east at 40
mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
These severe storms will be near...
Mason City around 435 AM CDT.
Other locations impacted by these severe thunderstorms include
Prentice, Topeka, Oakford, Jacksonville Municipal Airport, Concord,
Atterberry, Forest City, Philadelphia, and Goofy Ridge.
This also includes Jim Edgar Panther Creek Fish and Wildlife Area and
Sand Ridge State Forest.
This includes Interstate 72 between mile markers 71 and 73.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3990 8997 3990 8999 3987 8999 3973 9011
3979 9044 4045 8990 4042 8952
TIME...MOT...LOC 0930Z 270DEG 33KT 4039 8963 4003 8996
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Copple913
WWUS53 KILX 150939
SVSILX
Severe Weather Statement
National Weather Service Lincoln IL
439 AM CDT Sat Aug 15 2026
ILC017-125-129-137-179-150949-
/O.EXP.KILX.SV.W.0367.000000T0000Z-260815T0945Z/
Menard-Tazewell-Cass-Mason-Morgan-
439 AM CDT Sat Aug 15 2026
...THE SEVERE THUNDERSTORM WARNING FOR WESTERN MENARD...SOUTHWESTERN
TAZEWELL...EASTERN CASS...MASON AND NORTHEASTERN MORGAN COUNTIES WILL
EXPIRE AT 445 AM CDT...
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire. However, gusty
winds and heavy rain are still possible with these thunderstorms.
&&
LAT...LON 3990 8997 3990 8999 3987 8999 3973 9011
3979 9044 4045 8990 4042 8952
TIME...MOT...LOC 0939Z 270DEG 33KT 4038 8955 4002 8988
$$
CoppleWhat forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Lincoln, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 15, 2:20 AM CDT, 1 hour 23 minutes earlier. Its key messages:
- There is flash flooding ongoing across portions of central Illinois this morning, where thunderstorms track over areas that have already seen 4-6 inches of rain since Thursday. Areas north of a Havana to Bloomington line are most at risk.
- Storms have the potential to produce damaging winds today and tomorrow. SPC has a marginal (level 1 of 5) risk of severe weather for the weekend.
- The heat and humidity remain a concern for the weekend, with the hottest conditions in the southern half of the state.
Area forecast discussion, Aug 15, 2:20 AM CDT, 1 hour 23 minutes before
Area Forecast Discussion National Weather Service Lincoln IL 220 AM CDT Sat Aug 15 2026 .KEY MESSAGES... - There is flash flooding ongoing across portions of central Illinois this morning, where thunderstorms track over areas that have already seen 4-6 inches of rain since Thursday. Areas north of a Havana to Bloomington line are most at risk. - Storms have the potential to produce damaging winds today and tomorrow. SPC has a marginal (level 1 of 5) risk of severe weather for the weekend. - The heat and humidity remain a concern for the weekend, with the hottest conditions in the southern half of the state. && .DISCUSSION... Issued at 220 AM CDT Sat Aug 15 2026 Tonight, storms are moving across central IL. There is a low risk (but non-zero) for damaging winds within these storms, but the main concern is the flash flooding risk. WPC has areas near and north of I-72 in a moderate risk (level 3 of 4) for excessive rainfall for the overnight hours. The 00z sounding shows the environment having PWATs of 2.2-2.4 inches. Over the last few days, this area has gotten 3-6 inches of rain, with some locally higher amounts. The storms passing through tonight are expected to drop another 2-5 inches with the LPMM suggesting some localized pockets of up to 10 inches. Flash flood guidance seems a bit generous (too high). If the pockets of higher rain set up over where the ground is already extremely saturated, flash flooding is likely. For the remainder of the day after this morning round of convection exits about 15-16z, there is a marginal risk for severe weather for additional activity that will move through. It will be very similar to what has happened over the last few days. The next round of MCS activity will move into central IL by late evening and will continue into the overnight hours. The main concern will be damaging winds and the heavy rain potential. There is another marginal risk for severe weather again tomorrow for areas south of a Schuyler to McLean County line with a similar environment in place as previous days. The forecast will continue to evolve as we get newer runs of the models. Temperatures remain hot and humid. The heat advisory for south of I- 70 is valid through Sunday. Heat indices of 100-110 degrees are forecast through Sunday, but how far north these heat indices get will depend solely on the convection location. Like yesterday for example, the convection lingered further south longer than forecast, so heat indices struggled to hit triple digits. Next week may bring us a brief break in the active weather and the heat briefly. A high pressure area will set up over the Upper Mississippi Valley / Great Lakes region by Monday, behind a cold front that will move through central IL during the day. Temperatures starting Monday into much of the next week will be mainly in the upper 70s to 80s for highs and 60s to low 70s for lows. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1223 AM CDT Sat Aug 15 2026 Thunderstorms are moving across portions of central Illinois during the early overnight hours and expected to continue into Saturday morning before exiting east of the area. MVFR/IFR ceilings currently in place north of the terminals will sink south to along the I-74 corridor overnight, but confidence is currently low that it will reach as far south as SPI/DEC. Areas that do drop are expected to improve back to VFR early to mid Saturday afternoon as winds veer to SWerly. && .ILX WATCHES/WARNINGS/ADVISORIES... Flood Watch until 10 AM CDT this morning for ILZ027>031- 036>038-040-041-043>046-055-057. Heat Advisory until 8 PM CDT Sunday for ILZ066>068-071>073. && KEY MESSAGES...Copple DISCUSSION...Copple AVIATION...Deubelbeiss
Hazardous weather outlook, Aug 14, 3:00 PM CDT, 12 hours 43 minutes before
Hazardous Weather Outlook National Weather Service Lincoln IL 300 PM CDT Fri Aug 14 2026 ILZ027>031-036>038-040>057-061>063-066>068-071>073-151100- Knox-Stark-Peoria-Marshall-Woodford-Fulton-Tazewell-McLean-Schuyler- Mason-Logan-De Witt-Piatt-Champaign-Vermilion-Cass-Menard-Scott- Morgan-Sangamon-Christian-Macon-Moultrie-Douglas-Coles-Edgar-Shelby- Cumberland-Clark-Effingham-Jasper-Crawford-Clay-Richland-Lawrence- 300 PM CDT Fri Aug 14 2026 This Hazardous Weather Outlook is for central Illinois, east central Illinois, southeast Illinois and west central Illinois. .DAY ONE...Tonight. Widespread thunderstorm activity is likely tonight, mainly north of I-72. Locally strong to severe storms and flash flooding are possible. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. Hot and humid conditions will peak over the area this weekend. Peak afternoon heat indices will range from 103 to 112 Saturday, and 100 to 105 Sunday. Daily chances for thunderstorms exist through the weekend, mainly north of I-70 for Saturday. Some of these storms could be severe and produce heavy rain. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed after midnight. 37
In the hours before
Local storm report, Aug 15, 1:46 AM CDT, 1 hour 57 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
146 AM CDT Sat Aug 15 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0144 AM Flash Flood Tremont 40.53N 89.49W
08/15/2026 Tazewell IL Public
6 inches of water flowing over E Pearl
Street.
&&
RACLocal storm report, Aug 15, 2:12 AM CDT, 1 hour 31 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
212 AM CDT Sat Aug 15 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0209 AM Flash Flood 3 WNW Mackinaw 40.56N 89.40W
08/15/2026 Tazewell IL Public
Allentown Road about a mile west of
Allentown is flooded over.
&&
RACLocal storm report, Aug 15, 2:32 AM CDT, 1 hour 11 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
232 AM CDT Sat Aug 15 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0224 AM Flash Flood 2 ESE Bloomington 40.47N 88.96W
08/15/2026 McLean IL 911 Call Center
Vehicle stalled in flood waters, road is
impassable at Oakland Ave/Four Seasons Rd
and Prospect Rd / Grandview Dr.
&&
RACLocal storm report, Aug 15, 2:52 AM CDT, 51 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
252 AM CDT Sat Aug 15 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0244 AM Flash Flood 1 ENE Bloomington 40.49N 88.97W
08/15/2026 McLean IL 911 Call Center
Vehicle stalled in floodwater, road is
impassable.
&&
RACLocal storm report, Aug 15, 2:54 AM CDT, 49 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
254 AM CDT Sat Aug 15 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0252 AM Flash Flood Minier 40.43N 89.31W
08/15/2026 Tazewell IL Broadcast Media
Water entering basement egress window at a
home in Minier.
&&
RACLocal storm report, Aug 15, 3:24 AM CDT, 19 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
324 AM CDT Sat Aug 15 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0318 AM Flash Flood Fisher 40.32N 88.35W
08/15/2026 Champaign IL Broadcast Media
Reports of basements flooding in Fisher.
&&
RACThe office that day
Everything else NWS Lincoln, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 14, 11:56 PM CDT | Flash Flood Warning | ILX | Fulton, Knox, Mason, Peoria, Tazewell, Woodford | 7 hr |
| Aug 15, 1:09 AM CDT | Flash Flood Warning | ILX | McLean | 6 hr |
| Aug 15, 1:23 AM CDT | Severe Thunderstorm Warning | ILX | Fulton, Mason | 67 min |
| Aug 15, 1:51 AM CDT | Severe Thunderstorm Warning | ILX | Fulton | 24 min |
| Aug 15, 2:19 AM CDT | Flash Flood Warning | ILX | McLean | 5 hr |
| Aug 15, 2:23 AM CDT | Severe Thunderstorm Warning | ILX | Peoria, Tazewell | 38 min |
| Aug 15, 2:36 AM CDT | Flash Flood Warning | ILX | McLean | 6 hr |
| Aug 15, 3:23 AM CDT | Flash Flood Warning | ILX | Champaign | 5 hr |
| Aug 15, 3:54 AM CDT | Flash Flood Warning | ILX | Vermilion | 4 hr |
| Aug 15, 4:29 AM CDT | Special Weather Statement | ILX | Logan, Menard, Sangamon | 31 min |
| Aug 15, 5:33 AM CDT | Areal Flood Advisory | ILX | Morgan | 3 hr |
| Aug 15, 5:48 AM CDT | Flash Flood Warning | ILX | Champaign, Vermilion | 8 hr |
| Aug 15, 6:24 AM CDT | Special Weather Statement | ILX | Champaign, Piatt, Vermilion | 36 min |
| Aug 15, 6:37 AM CDT | Areal Flood Warning | ILX | Fulton, Knox, Mason, Peoria, Tazewell, Woodford | 27 hr |
| Aug 15, 7:33 AM CDT | Areal Flood Warning | ILX | McLean | 65 min |
| Aug 15, 7:40 AM CDT | Areal Flood Warning | ILX | McLean | 26 hr |
| Aug 15, 8:04 AM CDT | Flash Flood Warning | ILX | McLean | 5 hr |
| Aug 15, 8:38 AM CDT | Flash Flood Warning | ILX | McLean | 4 hr |
| Aug 15, 10:11 AM CDT | River Flood Warning | ILX | Cass, Fulton, Mason | 13 days |
| Aug 15, 10:12 AM CDT | River Flood Warning | ILX | Brown, Cass, Morgan, Schuyler | 14 days |
| Aug 15, 10:19 AM CDT | River Flood Warning | ILX | Piatt | 7 days |
| Aug 15, 12:40 PM CDT | Areal Flood Warning | ILX | McLean | 21 hr |
| Aug 15, 1:40 PM CDT | Areal Flood Warning | ILX | Champaign, Vermilion | 46 hr |
| Aug 15, 1:46 PM CDT | River Flood Warning | ILX | McLean, Tazewell, Woodford | 20 hr |
Nearby
Severe Thunderstorm Warnings in Illinois, 2026Every severe thunderstorm warning 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.