Hazard Report Provided By forecast.weather.gov

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
420 AM CDT Wed Aug 12 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-130930-
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-
420 AM CDT Wed Aug 12 2026 /520 AM EDT Wed Aug 12 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 75 mph.
     Level 1 of 5 Large Hail Risk...up to quarter size.
  Elevated Flooding Risk.

DISCUSSION...

Isolated thunderstorms are possible early this morning, the
strongest of which may be capable of producing brief hail and
localized downpours.

A fast-moving line of strong to severe thunderstorms is then
expected to move east across the area from mid-morning into early
this afternoon. These storms will have the potential to produce
damaging winds and isolated tornadoes, in addition to producing
torrential rains which may lead to localized flooding. At this
time, the greatest risk of severe would appear to be from the I-88
corridor south and eastward.

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

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

DISCUSSION...

An active weather pattern with periodic thunderstorm chances is
expected to persist into the weekend. Some of these storms may be
strong to severe at times, as well as capable of producing heavy
rainfall which could lead to flash flooding.

.SPOTTER INFORMATION STATEMENT...

  Spotters may be needed from mid-morning into early this
  afternoon.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the east-southeast at around 35 mph for early morning
  storms. If mid-morning storms form a bowing line, it may move east at
  45 to 55 mph.


$$

WATCH COUNTY NOTIFICATION FOR WATCH 574
NATIONAL WEATHER SERVICE CHICAGO IL
829 AM CDT WED AUG 12 2026

ILC031-043-089-INC073-089-127-121800-
/O.EXA.KLOT.SV.A.0574.000000T0000Z-260812T1800Z/

THE NATIONAL WEATHER SERVICE HAS EXTENDED SEVERE THUNDERSTORM
WATCH 574 TO INCLUDE THE FOLLOWING AREAS UNTIL 1 PM CDT THIS
AFTERNOON

IN ILLINOIS THIS WATCH INCLUDES 3 COUNTIES

IN NORTHEAST ILLINOIS

COOK                  DUPAGE                KANE

IN INDIANA THIS WATCH INCLUDES 3 COUNTIES

IN NORTHWEST INDIANA

JASPER                LAKE IN               PORTER

THIS INCLUDES THE CITIES OF AURORA, CAROL STREAM, CHESTERTON,
CHICAGO, DEMOTTE, DOWNERS GROVE, ELGIN, EVANSTON, GARY, HAMMOND,
LEMONT, LOMBARD, MERRILLVILLE, NAPERVILLE, OAK LAWN, ORLAND PARK,
PARK FOREST, PORTAGE, RENSSELAER, SCHAUMBURG, VALPARAISO,
AND WHEATON.

$$

Hazard Report Provided By forecast.weather.gov