Hazard Report Provided By forecast.weather.gov

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
403 AM CDT Thu Aug 13 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-140915-
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-
403 AM CDT Thu Aug 13 2026 /503 AM EDT Thu Aug 13 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...

  Elevated Thunderstorm Risk...with an associated:
     Level 1 of 5 Tornado Risk.
     Level 2 of 5 Damaging Wind Risk...up to 60 mph.
     Level 1 of 5 Large Hail Risk...up to quarter size.
  Elevated Flooding Risk tonight.
  Significant Fog Risk this morning.

DISCUSSION...

Areas of dense fog are expected early this morning mainly west
and south of Chicago.

There is a chance of thunderstorms this afternoon, and some of
these storms could be severe with primarily a damaging wind threat
mainly south of a Mendota to Rensselaer line.

Showers and thunderstorms are expected across the area tonight,
and are likely to pose a threat of locally heavy rainfall that may
lead to flooding . At this time, the heaviest rainfall is
expected to occur generally south of a Forreston Illinois to
Valparaiso Indiana line.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

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

DISCUSSION...

An active weather pattern is expected to persist into this
weekend, with periodic shower and thunderstorm chances. These
showers and storms will be capable of producing torrential
rainfall at times, which could lead to flooding or flash
flooding.

.SPOTTER INFORMATION STATEMENT...

  Spotters may be needed this afternoon within a region
   mainly south of a Mendota to Rensselaer late.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the southeast at 25 to 35 mph.

$$

Hazard Report Provided By forecast.weather.gov