Alert archive / Illinois / Flash Flood Warnings in 2026
Flash Flood Warning 67, NWS Lincoln, IL
NWS Lincoln, IL issued this flash flood warning at Aug 15, 2026, 2:36 AM CDT for McLean County, Illinois. It was in force for 6 hr. 15 reports 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
- Aug 15, 2026, 2:36 AM CDT (07:36 UTC)
- Expired
- Aug 15, 2026, 8:25 AM CDT
- In force
- 6 hr
- Issued by
- NWS Lincoln, IL
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County McLean County, IL
The radar
The Lincoln radar (KILX), 45 km from the middle of the area, began a volume at 07:38 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 |
|---|---|---|---|
| Aug 15, 2:44 AM CDT | FLASH FLOOD | 1 Ene Bloomington, IL | Vehicle stalled in floodwater, road is impassable. |
| Aug 15, 6:00 AM CDT | RAIN 5.57 | 2 S Central Illinois Ai, IL | Cocorahs station IL-MCL-56 Bloomington 3.9 ESE. |
| Aug 15, 6:10 AM CDT | FLASH FLOOD | Bloomington, IL | Most roadways being reported with standing water. |
| Aug 15, 7:00 AM CDT | RAIN 2.69 | 2 Wnw Normal, IL | Cocorahs station IL-MCL-66 Normal 1.4 WNW. |
| Aug 15, 7:00 AM CDT | RAIN 3.64 | Normal, IL | Cocorahs station IL-MCL-64 Normal 1.2 ESE. |
| Aug 15, 7:00 AM CDT | RAIN 3.64 | Normal, IL | Cocorahs station IL-MCL-64 Normal 1.2 ESE. |
| Aug 15, 7:00 AM CDT | RAIN 3.98 | 1 Sse Normal, IL | Cocorahs station IL-MCL-63 Normal 1.7 SE. |
| Aug 15, 7:00 AM CDT | RAIN 4.88 | 2 Se Bloomington, IL | Cocorahs station IL-MCL-84 Bloomington 0.9 SSE. |
| Aug 15, 7:00 AM CDT | RAIN 5.11 | 1 Ssw Bloomington, IL | Cocorahs station IL-MCL-60 Bloomington 1.6 WSW. |
| Aug 15, 7:00 AM CDT | RAIN 5.44 | 3 Ne Shirley, IL | Cocorahs station IL-MCL-81 Bloomington 4.1 SW. |
| Aug 15, 7:10 AM CDT | RAIN 5.1 | 2 Nnw Central Illinois, IL | Cocorahs station IL-MCL-17 Bloomington 2.7 NE. |
| Aug 15, 7:10 AM CDT | RAIN 5.1 | 2 Nw Central Illinois A, IL | Rainfall total from 1230am to 710am with additional rain falling at time of observation. |
| Aug 15, 8:00 AM CDT | RAIN 5.3 | 2 E Bloomington, IL | Rainfall since 1230 am with thunderstorms. |
| Aug 15, 8:00 AM CDT | RAIN 5.3 | 2 S Bloomington, IL | Cocorahs station IL-MCL-85 1 S Bloomington. |
| Aug 15, 8:00 AM CDT | RAIN 5.94 | 3 N Shirley, IL | Cocorahs station IL-MCL-39 Bloomington 5.0 WSW. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
Did it verify
Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this flash flood warning; the first came 8 minutes after it went out.
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, 7.6 hours before the alert went out and 48 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.
444
WGUS53 KILX 150736
FFWILX
ILC113-151330-
/O.NEW.KILX.FF.W.0067.260815T0736Z-260815T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
236 AM CDT Sat Aug 15 2026
The National Weather Service in Lincoln has issued a
* Flash Flood Warning for...
Central McLean County in central Illinois...
* Until 830 AM CDT.
* At 234 AM CDT, local law enforcement reported several impassable
roadways and multiple stalled vehicles. Between 2 and 3 inches of
rain have fallen. Additional rainfall amounts up to 2 inches are
possible in the warned area. Flash flooding is ongoing.
HAZARD...Life threatening flash flooding. Thunderstorms
producing flash flooding.
SOURCE...Law enforcement reported.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
Bloomington, Normal, Downs and Central Illinois Regional Airport.
This includes the following highways...
Interstate 39 between mile markers 0 and 1.
Interstate 74 between mile markers 125 and 140.
Interstate 55 between mile markers 155 and 167.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4042 8908 4055 8907 4053 8886 4040 8888
FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
MJA2 follow-up statements
723
WGUS53 KILX 151238
FFWILX
ILC113-151600-
/O.EXT.KILX.FF.W.0067.000000T0000Z-260815T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
738 AM CDT Sat Aug 15 2026
The National Weather Service in Lincoln has extended the
* Flash Flood Warning for...
Central McLean County in central Illinois...
* Until 1100 AM CDT.
* At 736 AM CDT, gauge reports indicated between 4 and 6.5 inches of
rain have fallen overnight. Flash flooding is already occurring.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Gauges reported.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Bloomington, Normal, Downs and Central Illinois Regional Airport.
This includes the following highways...
Interstate 39 between mile markers 0 and 1.
Interstate 74 between mile markers 125 and 140.
Interstate 55 between mile markers 155 and 166.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4042 8908 4055 8907 4053 8886 4040 8888
FLASH FLOOD...GAUGE INDICATED
$$
MJA979 WGUS73 KILX 151325 FFSILX Flash Flood Statement National Weather Service Lincoln IL 825 AM CDT Sat Aug 15 2026 ILC113-151335- /O.CAN.KILX.FF.W.0067.000000T0000Z-260815T1600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ McLean IL- 825 AM CDT Sat Aug 15 2026 ...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL MCLEAN COUNTY... The heavy rain has ended. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures. A Flood Watch remains in effect until 1000 AM CDT for portions of central, east central, and west central Illinois. && LAT...LON 4042 8908 4055 8907 4053 8886 4040 8888 $$ MJA
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 Aug 15, 2:20 AM CDT, 16 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, 16 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, 11 hours 36 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, 1:38 AM CDT, 58 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
138 AM CDT Sat Aug 15 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0135 AM Flash Flood Bloomington 40.48N 88.99W
08/15/2026 McLean IL Public
Several flooded roads reported on Douglas
Street and viaducts underwater, relayed by
broadcast media from viewer.
0135 AM Flash Flood 1 W Normal 40.51N 89.00W
08/15/2026 McLean IL Public
Adelaide and Bryan streets in Bloomington
are impassible and underwater, relayed by
broadcast media from viewer.
&&Local storm report, Aug 15, 1:46 AM CDT, 50 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, 24 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, 4 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.
&&
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, 3:23 AM CDT | Flash Flood Warning | ILX | Champaign | 5 hr |
| Aug 15, 3:43 AM CDT | Severe Thunderstorm Warning | ILX | Cass, Fulton, Mason, Menard, Morgan, Schuyler and 1 more | 62 min |
| 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
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.