Hazard Report Provided By forecast.weather.gov

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
301 AM CDT Sat Aug 15 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-160815-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
301 AM CDT Sat Aug 15 2026 /401 AM EDT Sat Aug 15 2026/

This Hazardous Weather Outlook is for portions of north central
Illinois...northeast Illinois and northwest Indiana.

.DAY ONE...Today and Tonight.

Weather hazards expected...

  Significant Flooding Risk south of Interstate 80 this morning.
  Limited Thunderstorm Risk...with an associated:
     Level 1 of 5 Damaging Wind Risk...up to 60 mph.

DISCUSSION...

Showers and thunderstorms will continue across northern Illinois
and northwest Indiana through the morning. Torrential rainfall is
occurring with these storms, especially south of interstate 80,
which could lead to flash flooding. Locally gusty winds cannot be
ruled out either with storms this morning.

Another period of showers and thunderstorms is expected with a
cold front tonight into Sunday. These storms may also produce
heavy downpours and locally gusty winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Sunday...
  Limited Flooding Risk.
  Limited Thunderstorm Risk...with an associated:
     Level 1 of 5 Severe Thunderstorm Risk.
Tuesday Night and Wednesday...
  Elevated Flooding Risk.
  Limited Thunderstorm Risk.

DISCUSSION...

A strong to locally severe storm cannot be ruled out Sunday,
mainly in the morning. Additional storm chances are expected
Tuesday night into Wednesday.

.SPOTTER INFORMATION STATEMENT...

  Spotters may be needed for flash flooding reports this morning.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the east at 30 mph.

$$

Flood Watch
National Weather Service Chicago IL
305 AM CDT Sat Aug 15 2026

ILZ008-010>013-020-103>106-151500-
/O.CON.KLOT.FA.A.0013.000000T0000Z-260815T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ogle-Lee-De Kalb-Kane-DuPage-Kendall-Northern Cook-Central Cook-
Southern Cook-Northern Will-
Including the cities of Naperville, Chicago, Oswego, Cicero,
Palatine, Des Plaines, Bolingbrook, Orland Park, Northbrook, Lombard,
Oak Forest, Mokena, Schaumburg, Plano, Oak Park, DeKalb, Sycamore,
Wheaton, Downers Grove, Rochelle, Oak Lawn, Calumet City, Byron,
Carol Stream, Aurora, Park Forest, La Grange, Plainfield, Yorkville,
Lemont, Elgin, Evanston, Joliet, Dixon, and Oregon
305 AM CDT Sat Aug 15 2026

...FLOOD WATCH REMAINS IN EFFECT UNTIL 10 AM CDT THIS MORNING...

* WHAT...Flash flooding caused by excessive rainfall continues to be
  possible.

* WHERE...Portions of north central and northeast Illinois, including
  the following areas, in north central Illinois, De Kalb, Lee and
  Ogle. In northeast Illinois, Central Cook, DuPage, Kane, Kendall,
  Northern Cook, Northern Will and Southern Cook.

* WHEN...Until 10 AM CDT this morning.

* IMPACTS...Creeks and streams may rise out of their banks. Flooding
  may occur in poor drainage and urban areas, especially in the
  vicinity of storm drains that are clogged by leaf debris.
  Underpasses and viaducts may flood in urban areas, as well.

* ADDITIONAL DETAILS...
  - Torrential rain-producing showers and storms is expected across
    the watch area through early this morning. Saturated soils and
    torrential downpours will set the stage for flash flooding.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts. Have multiple ways to receive warning
information including at least one way that will wake you up.

&&

$$

Flood Statement
National Weather Service Chicago IL
801 PM CDT Fri Aug 14 2026

...The Flood Warning is extended for the following rivers in
Illinois...

  Thorn Creek at Thornton affecting Cook County.

For the Thorn Creek...including Thornton...Minor flooding is
forecast.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Warning means water levels above flood stage are imminent or
may already be occurring. Persons along rivers and streams in the
warned area should take immediate precautions to protect life and
property.

These forecasts are based on observed precipitation as well as
forecast precipitation 24 hours into the future. Changes to the
rainfall forecast, or any additional rainfall after 24 hours, may
cause changes to these river forecasts.

Additional information is available at www.weather.gov.

The next statement will be issued by Saturday afternoon.

&&

ILC031-151915-
/O.EXT.KLOT.FL.W.0069.000000T0000Z-260817T1342Z/
/THNI2.1.ER.260814T1522Z.260816T0600Z.260817T0742Z.NO/
801 PM CDT Fri Aug 14 2026

...FLOOD WARNING NOW IN EFFECT UNTIL MONDAY MORNING...

* WHAT...Minor flooding is occurring and minor flooding is forecast.

* WHERE...Thorn Creek from Near Glenwood downstream to confluence
  with Little Calumet River, including the Thornton gauge.

* WHEN...Until Monday morning.

* IMPACTS...At 13.5 feet, Chicago Heights Glenwood Road threatened in
  Glenwood. Residential parking lots threatened along Margaret Street
  in Thornton.

* ADDITIONAL DETAILS...
  - At 7:45 PM CDT Friday the stage was 9.4 feet.
  - Forecast...The river may fall to near flood stage late this
    evening, although additional rainfall in the forecast may prolong
    flooding impacts, resulting in another rise on Saturday into
    Saturday evening.
  - Flood stage is 9.0 feet.
  - http://www.weather.gov/safety/flood

&&

LAT...LON 4161 8760 4158 8754 4151 8760 4154 8767


$$

Carlaw

Hazard Report Provided By forecast.weather.gov