Alert archive / Illinois / Flash Flood Warnings in 2026

Flash Flood Warning 78, NWS Lincoln, IL

August 19, 2026Champaign County, DeWitt County, Piatt County, Illinois

NWS Lincoln, IL issued this flash flood warning at Aug 19, 2026, 9:30 PM CDT for Champaign County, DeWitt County, Piatt County, Illinois. It was in force for 3 hr. 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 19, 2026, 9:30 PM CDT (02:30 UTC)
Expired
Aug 20, 2026, 12:30 AM CDT
In force
3 hr
Issued by
NWS Lincoln, IL
Area
Storm-based polygon
Flood severity
None

Counties Champaign County, IL, DeWitt County, IL, Piatt County, IL

The radar

The Lincoln radar (KILX), 55 km from the middle of the area, began a volume at 02:31 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 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 00:00Z, 2.5 hours before the alert went out and 8 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-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2026-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1062 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2026-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
1062 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
948 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

653 
WGUS53 KILX 200230
FFWILX
ILC019-039-147-200530-
/O.NEW.KILX.FF.W.0078.260820T0230Z-260820T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Lincoln IL
930 PM CDT Wed Aug 19 2026

The National Weather Service in Lincoln has issued a

* Flash Flood Warning for...
  Central De Witt County in central Illinois...
  Northern Piatt County in central Illinois...
  West Central Champaign County in east central Illinois...

* Until 1230 AM CDT.

* At 929 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 2.5 inches of 
  rain have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts of 2 to 3 inches are possible in 
  the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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...
  Mahomet, Mansfield, De Land, Weldon, White Heath, Seymour, De 
  Witt, Galesville, Lodge, Clinton Power Station and Lane.

This includes the following State Parks...
	Clinton Lake State Recreation Area.

This includes the following highways...
	 Interstate 72 between  mile markers 170 and 177.
	 Interstate 74 between  mile markers 163 and 172.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Move to higher ground now. Act quickly to protect your life.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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 4022 8890 4023 8870 4024 8840 4009 8838
      4008 8863 4008 8891

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

Auten
1 follow-up statement
794 
WGUS73 KILX 200533
FFSILX

Flash Flood Statement
National Weather Service Lincoln IL
1233 AM CDT Thu Aug 20 2026

ILC019-039-147-200543-
/O.EXP.KILX.FF.W.0078.000000T0000Z-260820T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Champaign IL-De Witt IL-Piatt IL-
1233 AM CDT Thu Aug 20 2026

...FLASH FLOOD WARNING HAS EXPIRED FOR CENTRAL DE WITT, NORTHERN 
PIATT AND WEST CENTRAL CHAMPAIGN COUNTIES...

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 100 AM CDT for portions of 
central, east central, and west central Illinois.

&&

LAT...LON 4022 8890 4023 8870 4024 8840 4009 8838
      4008 8863 4008 8891

$$

25

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 19, 6:39 PM CDT, 2 hours 51 minutes earlier. Its key messages:

  • Scattered showers and thunderstorms are expected through this evening, and into the overnight hours southeast of the IL river. Damaging winds, hail, heavy rains and localized flooding is in play today. A Flood Watch is posted until 1 am tonight from Fulton to Macon to Vermilion counties north where 1-2 inches and locally 2-4 inches of rain possible.
  • A persistent northwest flow will keep temperatures and humidity levels in check the next several days, with seasonable highs in the upper 70s to mid 80s.
Area forecast discussion, Aug 19, 6:39 PM CDT, 2 hours 51 minutes before
Area Forecast Discussion
National Weather Service Lincoln IL
639 PM CDT Wed Aug 19 2026

.KEY MESSAGES...

- Scattered showers and thunderstorms are expected through this
  evening, and into the overnight hours southeast of the IL
  river. Damaging winds, hail, heavy rains and localized
  flooding is in play today. A Flood Watch is posted until 1 am
  tonight from Fulton to Macon to Vermilion counties north where
  1-2 inches and locally 2-4 inches of rain possible.

- A persistent northwest flow will keep temperatures and
  humidity levels in check the next several days, with
  seasonable highs in the upper 70s to mid 80s.

&&

.DISCUSSION...
Issued at 245 PM CDT Wed Aug 19 2026

We continued the Flood Watch through 1 am tonight from Fulton,
Mason, Menard, Logan, Macon, Piatt, Champaign and Vermilion
counties north. Some areas could see 1-2 inches of rain through
early overnight in central IL with pockets of 2-4 inches
possible. PWATs are in the 1.6-2 inch range over CWA (highest
over southern CWA) and supports heavy rain threat next several
hours. Parts of the flood watch area has already seen 5-10
inches of rain since last Sunday Aug 9th.

Radar mosaic shows a few cells developing along a frontal trof
from southern Fulton county into central parts of McLean and
Ford county. Had a recent report and photo of a funnel clouds in
Bloomington and Galva (southern Henry county). Moderately
unstable tropical airmass over CWA with SB CAPES of 2-3k j/kg,
and highest over northern/nw CWa. The 0-6 km bulk shear values
are at moderate levels too from 35-45 kts over CWA and highest
over southern/sw CWA. A cold front over northern/nw IL will push
se thru CWA during tonight, while an associated short wave trof
over western Iowa tracks se through IL during tonight. This
will interact with the tropical air mass to likely produce
scattered showers and thunderstorms. SPC Day1 outlook has
marginal risk of severe storms over CWA for large hail and
damaging winds while tornado threat is over southern IL south of
CWA though a few more funnels may occur along weak trof over
northern CWA through 00Z/7 pm.

Quieter weather expected on Thursday and Thu night as cold
front nearing the Ohio river by sunrise Thu pushes into central
KY. Highs in the lower 80s Thu with dewpoints in the mid to
upper 60s. A northern stream system approached IL on Friday
bringing 20-40% chance of convection over northern cWA Fri
afternoon and across central IL friday night especially Fri
evening. SPC keeps severe risk west nw of IL on Fri with slight
risk of Nebraska and northeast KS. Highs in the low to mid 80s
Friday with dewpoints sneaking up into the upper 60s/lower 70s
by Fri afternoon.

Fairly quiet weather this weekend into early next week with just
slight pops at times while most areas should stay dry. Another
cold front to sweep through IL early Saturday and bringing in
less humid air during this weekend. Lows Saturday night in the
lower 60s and lows in upper 50s to around 60F Sunday night
making for more comfortable nights ahead. Highs Sat 80-85
(warmest in southeast IL) and upper 70s/lower 80s Sunday/Monday.
Still pretty not much weather expected into middle of next week
with some moderation of temperatures and dewpoints to more
summerlike readings.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 632 PM CDT Wed Aug 19 2026

Scattered showers and thunderstorms are currently ongoing along
a slowly sagging cold front. Thus, a TEMPO group for TSRA and
MVFR conditions has been added to the regional TAF sites between
00z-06z. Beyond that timeframe, a return to VFR conditions is
expected across the board. However, we will need to watch for
patchy dense fog prior to 12z, which could temporarily lower
visibility into the MVFR/IFR range.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 1 AM CDT Thursday for ILZ027>031-036>038-
041>046-048-053.

&&

KEY MESSAGES...07
DISCUSSION...07
AVIATION...MJA
Hazardous weather outlook, Aug 19, 2:52 PM CDT, 6 hours 38 minutes before
Hazardous Weather Outlook
National Weather Service Lincoln IL
252 PM CDT Wed Aug 19 2026

ILZ027>031-036>038-040>057-061-201100-
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-
252 PM CDT Wed Aug 19 2026

This Hazardous Weather Outlook is for central Illinois, east
central Illinois and west central Illinois.

.DAY ONE...Late This Afternoon and Tonight.

Scattered thunderstorms are expected to develop this afternoon and
persist into the evening, producing locally heavy rain which could
lead to flash flooding. A few of the storms may be strong or briefly
severe, producing damaging winds and large hail.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Additional thunderstorms are possible Friday afternoon and night.
The risk of severe weather is low.

Flooding will continue into the weekend for portions of the Illinois
and Sangamon Rivers.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be required through this evening.

Expected storm motion is to the east around 25 mph.

ILZ062-063-066>068-071>073-201100-
Cumberland-Clark-Effingham-Jasper-Crawford-Clay-Richland-Lawrence-
252 PM CDT Wed Aug 19 2026

This Hazardous Weather Outlook is for east central Illinois and
southeast Illinois.

.DAY ONE...Late This Afternoon and Tonight.

Scattered thunderstorms are expected this evening, lingering past
midnight. Isolated damaging wind gusts and locally heavy rain which
could lead to flash flooding are the primary hazards.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Flooding will linger on the Wabash River for several days.
Otherwise, no hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be required this evening.

Expected storm motion is to the east around 25 mph.

Geelhart

In the hours before

Special weather statement, Aug 19, 8:27 PM CDT, 1 hour 3 minutes before
Special Weather Statement
National Weather Service Lincoln IL
827 PM CDT Wed Aug 19 2026

ILZ042-200200-
Logan-
827 PM CDT Wed Aug 19 2026

...A STRONG THUNDERSTORM WILL IMPACT LOGAN COUNTY THROUGH 900 PM
CDT...

At 827 PM CDT, Doppler radar was tracking a strong thunderstorm near
New Holland, or 7 miles west of Lincoln, moving east at 40 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Lincoln, Atlanta, Mount Pulaski, Emden, Hartsburg, New Holland,
Chestnut, Beason, Lawndale, and Broadwell.

This includes the following highways...
 Interstate 155 between mile markers 0 and 10.
 Interstate 55 between mile markers 116 and 140.

This also includes Edward R. Madigan State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4004 8957 4010 8958 4031 8959 4032 8928
      4028 8927 4027 8916 3997 8915
TIME...MOT...LOC 0127Z 278DEG 33KT 4019 8950

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Auten
Local storm report, Aug 19, 9:04 PM CDT, 26 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
904 PM CDT Wed Aug 19 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0903 PM     Flash Flood      3 ENE Morton            40.63N 89.41W
08/19/2026                   Tazewell           IL   Emergency Mngr

            Flowing water reported over the road near
            the intersection of Harding Rd and
            Washington Rd.

&&
Special weather statement, Aug 19, 9:05 PM CDT, 25 minutes before
Special Weather Statement
National Weather Service Lincoln IL
905 PM CDT Wed Aug 19 2026

ILZ042-043-200245-
Logan-De Witt-
905 PM CDT Wed Aug 19 2026

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL LOGAN AND
SOUTHWESTERN DE WITT COUNTIES THROUGH 945 PM CDT...

At 905 PM CDT, Doppler radar was tracking a strong thunderstorm over
Beason, or 9 miles west of Clinton, moving east at 30 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Clinton, Wapella, Kenney, De Witt, Clinton Power Station, Weldon
Springs State Park, Lane, Midland City, and Hallsville.

This also includes Clinton Lake State Recreation Area and Weldon
Springs State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4006 8919 4022 8918 4021 8876 4006 8876
TIME...MOT...LOC 0205Z 277DEG 28KT 4014 8914

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Auten
Local storm report, Aug 19, 9:24 PM CDT, 6 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
924 PM CDT Wed Aug 19 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0921 PM     Tstm Wnd Dmg     Kenney                  40.10N 89.08W
08/19/2026                   De Witt            IL   Emergency Mngr

            Large branch (unknown size) blocking road at
            E Benjamin and Fuller street.

&&

RC
Local storm report, Aug 19, 9:29 PM CDT, 1 minute before
Preliminary Local Storm Report
National Weather Service Lincoln IL
929 PM CDT Wed Aug 19 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0928 PM     Rain             3 N Weldon              40.16N 88.74W
08/19/2026  M2.20 Inch       De Witt            IL   Public

&&
Local storm report, Aug 19, 9:30 PM CDT, 0 minutes before
Preliminary Local Storm Report
National Weather Service Lincoln IL
930 PM CDT Wed Aug 19 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0930 PM     Rain             1 ENE Morton            40.62N 89.44W
08/19/2026  M5.00 Inch       Tazewell           IL   Public

            Via PWS.

&&

The office that day

Everything else NWS Lincoln, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 19, 7:13 PM CDTFlash Flood WarningILXMarshall, Stark2 hr
Aug 19, 8:27 PM CDTSpecial Weather StatementILXLogan33 min
Aug 19, 9:05 PM CDTSpecial Weather StatementILXDeWitt40 min
Aug 19, 10:44 PM CDTFlash Flood WarningILXChampaign3 hr
Aug 19, 11:32 PM CDTFlash Flood WarningILXChampaign, Vermilion3 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.