Alert archive / Illinois / Flash Flood Warnings in 2026
Flash Flood Warning 9, NWS Lincoln, IL
NWS Lincoln, IL issued this flash flood warning at May 18, 2026, 2:52 PM CDT for Clay County, Illinois. It was in force for 3 hr. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- May 18, 2026, 2:52 PM CDT (19:52 UTC)
- Expired
- May 18, 2026, 6:00 PM CDT
- In force
- 3 hr
- Issued by
- NWS Lincoln, IL
- Area
- Storm-based polygon
- Flood severity
- None
County Clay County, IL
The radar
The Evansville,IN radar (KVWX), 78 km from the middle of the area, began a volume at 19:54 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 was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 18, 5:08 PM CDT | RAIN 1.02 | 2 Sse Clay City, IL | Mesonet station AX448 CLAY CITY. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood 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 12:00Z, 7.9 hours before the alert went out and 166 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
- 850 J/kg
- Mixed-layer CIN
- -80 J/kg
- Mixed-layer LCL
- 966 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 301 m²/s²
- 0-3 km storm-relative helicity
- 331 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 8.8
The text
As transmitted.
145
WGUS53 KILX 181952
FFWILX
ILC025-182300-
/O.NEW.KILX.FF.W.0009.260518T1952Z-260518T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
252 PM CDT Mon May 18 2026
The National Weather Service in Lincoln has issued a
* Flash Flood Warning for...
Southern Clay County in south central Illinois...
* Until 600 PM CDT.
* At 251 PM CDT, emergency management reported thunderstorms
producing heavy rain across the warned area. Between 1 and 2
inches of rain have fallen. The expected rainfall rate is 1 to 2
inches in 4 hours. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Emergency management reported.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Flora, Clay City, Xenia and Flora Municipal Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
&&
LAT...LON 3860 8828 3861 8870 3872 8870 3877 8837
FLASH FLOOD...OBSERVED
EXPECTED RAINFALL RATE...1-2 INCHES IN 4 HOURS
$$
Barnes2 follow-up statements
460
WGUS73 KILX 182056
FFSILX
Flash Flood Statement
National Weather Service Lincoln IL
356 PM CDT Mon May 18 2026
ILC025-182300-
/O.CON.KILX.FF.W.0009.000000T0000Z-260518T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clay IL-
356 PM CDT Mon May 18 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM CDT THIS EVENING
FOR SOUTHERN CLAY COUNTY...
At 356 PM CDT, emergency management reported thunderstorms producing
heavy rain across the warned area. Between 2 and 4.5 inches of rain
have fallen. Additional rainfall amounts of 0.5 to 1 inch are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Emergency management reported.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Flora, Clay City, Xenia and Flora Municipal Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
&&
LAT...LON 3860 8828 3861 8870 3872 8870 3877 8837
FLASH FLOOD...OBSERVED
$$
AAT028 WGUS73 KILX 182253 FFSILX Flash Flood Statement National Weather Service Lincoln IL 553 PM CDT Mon May 18 2026 ILC025-182303- /O.EXP.KILX.FF.W.0009.000000T0000Z-260518T2300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Clay IL- 553 PM CDT Mon May 18 2026 ...FLASH FLOOD WARNING WILL EXPIRE AT 6 PM CDT THIS EVENING FOR SOUTHERN CLAY COUNTY... Portions of the Flash Flood Warning have been converted to an Areal Flood Warning through 600 AM CDT Tuesday. A Flood Watch remains in effect until 1000 PM CDT for portions of central, east central, and southeast Illinois. && LAT...LON 3860 8828 3861 8870 3872 8870 3877 8837 $$ Deubelbeiss
What forecasters said that day
The local office's own words before this flash flood 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 flash flood warning went out at May 18, 2:23 PM CDT, 29 minutes earlier. Its key messages:
- Repeating rounds of showers and storms could cause flash flooding south of a Shelbyville to Paris line through this evening. A Flood Watch is in effect for these areas.
- Additional thunderstorms will develop along an advancing cold front on Tuesday, with a slight risk (level 2 of 5) for severe storms east of Interstate 55. Damaging winds, large hail, and heavy rainfall would be the most likely hazards.
Area forecast discussion, May 18, 2:23 PM CDT, 29 minutes before
Area Forecast Discussion National Weather Service Lincoln IL 223 PM CDT Mon May 18 2026 .KEY MESSAGES... - Repeating rounds of showers and storms could cause flash flooding south of a Shelbyville to Paris line through this evening. A Flood Watch is in effect for these areas. - Additional thunderstorms will develop along an advancing cold front on Tuesday, with a slight risk (level 2 of 5) for severe storms east of Interstate 55. Damaging winds, large hail, and heavy rainfall would be the most likely hazards. && .DISCUSSION... Issued at 223 PM CDT Mon May 18 2026 A line of showers and thunderstorms has stalled out south of the I- 72 corridor this afternoon. Although wind shear has increased over this area since this morning, instability has significantly waned and has prevented storms from largely becoming organized. Despite this, cannot completely rule out a strong updraft or two over the next few hours in far southeast Illinois where RAP mesoanalysis shows SBCAPE of 1000+ J/kg. If any strong storms do occur, damaging winds would be possible. The main threat through the evening will be heavy rainfall with PWATS up around 1.5 to 2 inches and hourly rainfall rates up around 1 inch in the heaviest of storms. A Flood Watch has been issued for areas south of a Shelbyville to Paris line through this evening. Further west, additional thunderstorms have developed over the central Plains ahead of a cold front and will track east through tonight, approaching western Illinois sometime after midnight. These storms should weaken as they enter the area due to lack of instability, though they could still produce gusty subsevere winds as they track through the western half of the state. Most of the shower and storm activity should subside by or before daybreak. The cold front will approach the I-55 corridor around midday Tuesday and be the focus for additional storm development by afternoon. However, one limiting factor will be how long cloud cover from the overnight storms lingers, which would ultimately limit our destabilization potential. CAMS suggest destabilization will be most likely in east-central and southeast Illinois by mid to late afternoon in a moderately sheared environment. However, this appears to be highly conditional at this point. If storms do develop, damaging winds, large hail, and heavy rainfall will be the primary concerns. A drier and cooler period shapes up for midweek as high pressure ridging slides through the Upper Midwest. This will be relatively short-lived as upper troughing moves into the central US and shortwave energy sends several rounds of precipitation through Illinois this weekend into early next week. While the severe weather risk appears low through this period, better moisture/instability building by late weekend/early next week will support thunderstorms at times. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1237 PM CDT Mon May 18 2026 Precipitation will continue to slowly spread east along a remnant outflow boundary through the remainder of this afternoon. Although most of the thunderstorm activity should remain south of the airfields, can't completely rule out a low chance for lightning at KSPI and KDEC through about 00Z. After a lull this evening, another wave of storms will approach from the west late tonight into the early morning hours of Tuesday. PROB30 groups remain in place for this potential at all locations. South-southwest winds will be breezy through Tuesday, with gusts between 20-25 kts. && .ILX WATCHES/WARNINGS/ADVISORIES... Flood Watch until 10 PM CDT this evening for ILZ054>057- 061>063-066>068-071>073. && KEY MESSAGES...NMA DISCUSSION...NMA AVIATION...NMA
Hazardous weather outlook, May 18, 2:47 PM CDT, 5 minutes before
Hazardous Weather Outlook National Weather Service Lincoln IL 247 PM CDT Mon May 18 2026 ILZ054>057-061>063-066>068-071>073-192000- Moultrie-Douglas-Coles-Edgar-Shelby-Cumberland-Clark-Effingham- Jasper-Crawford-Clay-Richland-Lawrence- 247 PM CDT Mon May 18 2026 This Hazardous Weather Outlook is for central Illinois, east central Illinois and southeast Illinois. .DAY ONE...Tonight. Additional thunderstorms are possible overnight west of I-55. Primary hazards with any stronger storms will be gusty winds and lightning. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Thunderstorms will redevelop ahead of a cold front Tuesday afternoon and evening, mainly east of I-55. Damaging wind gusts, large hail, and heavy rain are all possible. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated through tonight. ILZ027>031-036>038-040>053-192000- Knox-Stark-Peoria-Marshall-Woodford-Fulton-Tazewell-McLean-Schuyler- Mason-Logan-De Witt-Piatt-Champaign-Vermilion-Cass-Menard-Scott- Morgan-Sangamon-Christian-Macon- 247 PM CDT Mon May 18 2026 This Hazardous Weather Outlook is for central Illinois, east central Illinois and west central Illinois. .DAY ONE...Tonight. Repeated rounds of storms could cause flash flooding through this evening. A Flood Watch is in effect through tonight. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Thunderstorms will redevelop ahead of a cold front Tuesday afternoon and evening. Damaging wind gusts, large hail, and heavy rain are all possible. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated through tonight, though rainfall reports are appreciated. NMA
In the hours before
Local storm report, May 18, 1:11 PM CDT, 1 hour 41 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
111 PM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1255 PM Rain Effingham County Airpor 39.07N 88.53W
05/18/2026 M2.30 Inch Effingham IL AWOS
AWOS station K1H2 Effingham Arpt.
0100 PM Rain 2 NNE Effingham 39.15N 88.53W
05/18/2026 M1.58 Inch Effingham IL Mesonet
Mesonet station DW5254 Baraboo.
&&Local storm report, May 18, 1:41 PM CDT, 1 hour 11 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
141 PM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0123 PM Flood Montrose 39.17N 88.38W
05/18/2026 Effingham IL Broadcast Media
Water flowing over country roads in southern
Effingham county. Some debris washed onto a
few roads from nearby farm fields.
&&Local storm report, May 18, 1:44 PM CDT, 1 hour 8 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
144 PM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0123 PM Flood Altamont 39.06N 88.75W
05/18/2026 Effingham IL Broadcast Media
Lots of fields with standing water and some
water flowing over low lying country roads
over central and southern Effingham county.
&&Local storm report, May 18, 1:46 PM CDT, 1 hour 6 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
146 PM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0130 PM Flood Teutopolis 39.13N 88.47W
05/18/2026 Effingham IL Emergency Mngr
Water flowing over several low lying country
roads in central and southern Effingham
county. Water approaching highway 40 between
Montrose and Teutopolis.
&&Local storm report, May 18, 1:47 PM CDT, 1 hour 5 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
147 PM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0135 PM Rain Effingham County Airpor 39.07N 88.53W
05/18/2026 M2.43 Inch Effingham IL AWOS
AWOS station K1H2 Effingham Arpt.
0136 PM Rain Watson 39.02N 88.57W
05/18/2026 M2.30 Inch Effingham IL Mesonet
Mesonet station FW0190 Watson.
0130 PM Rain 2 NNE Effingham 39.15N 88.53W
05/18/2026 M1.86 Inch Effingham IL Mesonet
Mesonet station DW5254 Baraboo.
0130 PM Rain 1 SW Newton 38.98N 88.17W
05/18/2026 M1.60 Inch Jasper IL Mesonet
Mesonet station EW2373 Newton.
0130 PM Rain Teutopolis 39.13N 88.48W
05/18/2026 M1.51 Inch Effingham IL Mesonet
Mesonet station FW1289 Teutopolis.
0115 PM Rain 1 SW Newton 38.98N 88.17W
05/18/2026 M1.50 Inch Jasper IL Mesonet
Mesonet station EW2373 Newton.
0115 PM Rain Edgar County Airport 39.70N 87.67W
05/18/2026 M1.37 Inch Edgar IL AWOS
AWOS station KPRG Edgar Co. Arpt.
&&Local storm report, May 18, 2:51 PM CDT, 1 minute before
Preliminary Local Storm Report
National Weather Service Lincoln IL
251 PM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0237 PM Flood Flora 38.67N 88.49W
05/18/2026 Clay IL Emergency Mngr
Several flooded roads in Flora.
&&The office that day
Everything else NWS Lincoln, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 18, 8:18 AM CDT | Severe Thunderstorm Warning | ILX | Fulton, Logan, Mason, Peoria, Tazewell | 39 min |
| May 18, 9:24 AM CDT | Severe Thunderstorm Warning | ILX | McLean, Marshall, Woodford | 22 min |
| May 18, 9:36 AM CDT | Severe Thunderstorm Warning | ILX | DeWitt, Macon, Piatt | 39 min |
| May 18, 9:44 AM CDT | Severe Thunderstorm Warning | ILX | Coles, Douglas, Edgar | 46 min |
| May 18, 9:49 AM CDT | Severe Thunderstorm Warning | ILX | Christian, Macon, Shelby | 41 min |
| May 18, 10:20 AM CDT | Severe Thunderstorm Warning | ILX | Champaign, Douglas, Macon, Moultrie, Piatt | 40 min |
| May 18, 10:28 AM CDT | Severe Thunderstorm Warning | ILX | Clay, Effingham, Jasper | 47 min |
| May 18, 11:24 AM CDT | Flood Watch | ILX | Clark, Clay, Coles, Crawford, Cumberland, Douglas and 7 more | 11 hr |
| May 18, 11:54 AM CDT | Areal Flood Advisory | ILX | Clay, Effingham, Jasper | 6 hr |
| May 18, 12:12 PM CDT | River Flood Warning | ILX | Clay, Richland | 7 days |
| May 18, 1:44 PM CDT | Flash Flood Warning | ILX | Clay, Effingham, Jasper | 4 hr |
| May 18, 3:23 PM CDT | Areal Flood Advisory | ILX | Clay, Crawford, Jasper, Lawrence, Richland | 3 hr |
| May 18, 5:50 PM CDT | Areal Flood Warning | ILX | Clay, Effingham, Jasper | 15 hr |
| May 18, 5:58 PM CDT | River Flood Warning | ILX | Lawrence | 4 days |
Nearby
Flash Flood Warnings in Illinois, 2026Every flash flood 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.