Hazard Report Provided By forecast.weather.gov

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
146 PM CDT Sat Apr 18 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-191900-
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-
146 PM CDT Sat Apr 18 2026 /246 PM EDT Sat Apr 18 2026/

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

.DAY ONE...This Afternoon and Tonight.

Weather hazards expected...

 Elevated Frost Risk overnight.

DISCUSSION...

Locally sub-freezing temperatures are possible tonight in outlying
areas, with many locations outside of the urban corridor dropping
into the low to mid 30s. Sheltered areas will be susceptible to
frost formation.

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

Sunday Night...
 Significant Frost and Freeze Risk.
Friday...
 Limited Thunderstorm Risk.

.SPOTTER INFORMATION STATEMENT...

  Spotter activation will not be necessary through tonight.

$$

Flood Watch
National Weather Service Chicago IL
145 PM CDT Sat Apr 18 2026

...The National Weather Service in Chicago IL has issued a Flood
Watch for the following rivers in Illinois...

  Rock River at Dixon affecting Lee and Ogle Counties.

For the Rock River...including Dixon...flooding is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Watch means water levels above flood stage are possible, but
not yet certain, based upon the latest forecasts. Persons along
rivers and streams in the watch area should monitor the latest
forecasts and be prepared to take action should flooding develop.

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 Sunday morning.

&&

ILZ008-010-191245-
/O.NEW.KLOT.FL.A.0027.260420T0600Z-000000T0000Z/
/DXRI2.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.NO/
145 PM CDT Sat Apr 18 2026

...FLOOD WATCH IN EFFECT FROM LATE SUNDAY NIGHT UNTIL FURTHER
NOTICE...

* WHAT...Flooding is possible.

* WHERE...Rock River from Castle Rock State Park near Oregon
  downstream to Lee County line, including the Dixon gauge.

* WHEN...From late Sunday night until further notice.

* IMPACTS...At 16.0 feet, N Canal Drive threatened in Woodland
  Shores. Water overflows low-lying banks along west First Street in
  Dixon. Residential property threatened near Sherman Avenue and
  River Street in Dixon.

* ADDITIONAL DETAILS...
  - At 1:15 PM CDT Saturday the stage was 14.8 feet.
  - Forecast...Flood stage may be reached early next week.
  - Flood stage is 16.0 feet.
  - http://www.weather.gov/safety/flood

&&

LAT...LON 4183 8963 4192 8948 4198 8942 4195 8932
      4183 8943 4175 8963

$$

Borchardt

URGENT - WEATHER MESSAGE
National Weather Service Chicago IL
129 PM CDT Sat Apr 18 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-106>108-INZ001-002-
010-011-019-190430-
/O.NEW.KLOT.FR.Y.0001.260419T0500Z-260419T1400Z/
/O.NEW.KLOT.FZ.A.0001.260420T0500Z-260420T1400Z/
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-La
Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-Northern
Will-Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-
Benton-
Including the cities of Naperville, Downers Grove, Manhattan,
Ottawa, Gilman, McHenry, Chesterton, Waukegan, Elgin, DeKalb,
Kankakee, Rochelle, Crete, Oregon, Watseka, Valparaiso, Crystal
Lake, Beecher, Fairbury, Roselawn, Aurora, Mendota, Coal City,
Hammond, La Salle, Mundelein, Plainfield, Woodstock, Buffalo
Grove, Gary, Bolingbrook, Bradley, Peotone, Portage, Wheaton,
Gibson City, Oswego, Carol Stream, Channahon, Belvidere,
Yorkville, Fowler, Pontiac, Plano, Gurnee, Marseilles, Morris,
Minooka, Paxton, Morocco, Rockford, Streator, Sycamore, Lombard,
Bourbonnais, Rensselaer, Merrillville, DeMotte, Byron, Algonquin,
Oxford, Mokena, Kentland, Joliet, Wilmington, Dixon, and Dwight
129 PM CDT Sat Apr 18 2026 /229 PM EDT Sat Apr 18 2026/

...FROST ADVISORY IN EFFECT FROM MIDNIGHT CDT /1 AM EDT/ TONIGHT TO
9 AM CDT /10 AM EDT/ SUNDAY...
...FREEZE WATCH IN EFFECT FROM LATE SUNDAY NIGHT THROUGH MONDAY
MORNING...

* WHAT...For the Frost Advisory, temperatures as low as 33 will
  result in frost formation. For the Freeze Watch, sub-freezing
  temperatures as low as 28 possible.

* WHERE...Portions of central, east central, north central, and
  northeast Illinois and northwest Indiana.

* WHEN...For the Frost Advisory, from midnight CDT /1 AM EDT/
  tonight to 9 AM CDT /10 AM EDT/ Sunday. For the Freeze Watch, from
  late Sunday night through Monday morning.

* IMPACTS...Frost and freeze conditions could kill crops, other
  sensitive vegetation and possibly damage unprotected outdoor
  plumbing. Frost could harm sensitive outdoor vegetation. Sensitive
  outdoor plants may be killed if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

URGENT - WEATHER MESSAGE
National Weather Service Chicago IL
129 PM CDT Sat Apr 18 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-106>108-INZ001-002-
010-011-019-190430-
/O.NEW.KLOT.FR.Y.0001.260419T0500Z-260419T1400Z/
/O.NEW.KLOT.FZ.A.0001.260420T0500Z-260420T1400Z/
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-La
Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-Northern
Will-Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-
Benton-
Including the cities of Naperville, Downers Grove, Manhattan,
Ottawa, Gilman, McHenry, Chesterton, Waukegan, Elgin, DeKalb,
Kankakee, Rochelle, Crete, Oregon, Watseka, Valparaiso, Crystal
Lake, Beecher, Fairbury, Roselawn, Aurora, Mendota, Coal City,
Hammond, La Salle, Mundelein, Plainfield, Woodstock, Buffalo
Grove, Gary, Bolingbrook, Bradley, Peotone, Portage, Wheaton,
Gibson City, Oswego, Carol Stream, Channahon, Belvidere,
Yorkville, Fowler, Pontiac, Plano, Gurnee, Marseilles, Morris,
Minooka, Paxton, Morocco, Rockford, Streator, Sycamore, Lombard,
Bourbonnais, Rensselaer, Merrillville, DeMotte, Byron, Algonquin,
Oxford, Mokena, Kentland, Joliet, Wilmington, Dixon, and Dwight
129 PM CDT Sat Apr 18 2026 /229 PM EDT Sat Apr 18 2026/

...FROST ADVISORY IN EFFECT FROM MIDNIGHT CDT /1 AM EDT/ TONIGHT TO
9 AM CDT /10 AM EDT/ SUNDAY...
...FREEZE WATCH IN EFFECT FROM LATE SUNDAY NIGHT THROUGH MONDAY
MORNING...

* WHAT...For the Frost Advisory, temperatures as low as 33 will
  result in frost formation. For the Freeze Watch, sub-freezing
  temperatures as low as 28 possible.

* WHERE...Portions of central, east central, north central, and
  northeast Illinois and northwest Indiana.

* WHEN...For the Frost Advisory, from midnight CDT /1 AM EDT/
  tonight to 9 AM CDT /10 AM EDT/ Sunday. For the Freeze Watch, from
  late Sunday night through Monday morning.

* IMPACTS...Frost and freeze conditions could kill crops, other
  sensitive vegetation and possibly damage unprotected outdoor
  plumbing. Frost could harm sensitive outdoor vegetation. Sensitive
  outdoor plants may be killed if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Flood Statement
National Weather Service Chicago IL
952 AM CDT Sat Apr 18 2026

...The Flood Warning continues for the following rivers in
Illinois...

  Pecatonica River near Shirland affecting Winnebago County.

  Rock River at Byron affecting Ogle County.

  Rock River at Rockton affecting Winnebago County.

  Rock River at Latham Park affecting Winnebago County.

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

  Kishwaukee River near Perryville affecting Winnebago County.

For the Rock River...including Rockton, Latham Park, Rockford
(Auburn Street), Byron, Dixon...Moderate 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 late tonight.

&&

ILC141-190900-
/O.CON.KLOT.FL.W.0026.000000T0000Z-000000T0000Z/
/BYRI2.2.ER.260417T1800Z.260420T1800Z.000000T0000Z.NO/
952 AM CDT Sat Apr 18 2026

...FLOOD WARNING REMAINS IN EFFECT UNTIL FURTHER NOTICE...

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

* WHERE...Rock River from Confluence with Kishwaukee River to Castle
  Rock State Park near Oregon, including the Byron gauge.

* WHEN...Until further notice.

* IMPACTS...At 15.5 feet, Water threatens lower sections of the
  water treatment plant property in Byron. Water threatens IL-2 west
  of Byron.

* ADDITIONAL DETAILS...
  - At 9:15 AM CDT Saturday the stage was 13.8 feet.
  - Recent Activity...The maximum river stage in the 24 hours
    ending at 9:15 AM CDT Saturday was 13.8 feet.
  - Forecast...The river is expected to rise to a crest of 15.3
    feet early Monday afternoon.
  - Flood stage is 13.0 feet.
  - Flood History...This crest compares to a previous crest of
    15.4 feet on 07/22/2017.
  - http://www.weather.gov/safety/flood

&&

LAT...LON 4222 8917 4218 8910 4207 8927 4195 8932
      4198 8942 4211 8937


$$

Hazard Report Provided By forecast.weather.gov