Joliet, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

363
FXUS63 KLOT 141727
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1227 PM CDT Sun Jun 14 2026

.KEY MESSAGES...

- Scattered showers/isolated thunderstorms this morning then
  breezy and much cooler.

- Dangerous swimming conditions at Indiana Lake Michigan beaches
  today and possibly again Thursday.

- Shower and thunderstorm chances return Tuesday and Wednesday.
  There is the possibility for another severe weather event on
  Wednesday along with heavy rain/flooding.

&&

.DISCUSSION...
Issued at 234 AM CDT Sun Jun 14 2026

Scattered showers and thunderstorms moving across far eastern IL
and northwest IN will move east of the local area in the next
few hours with heavy rain the main threat with this activity.
The cold front will continue to move across the rest of the area
through the morning hours, shifting winds to the northwest.
Models are in good agreement with at least scattered showers
continuing to move across the area through mid morning and this
trend looks reasonable given current activity across eastern IA
and western IL. May need to have higher pops for this activity,
which will end from west to east during the mid/late morning.
There will remain a low chance for a few thunderstorms with this
activity but not expecting the activity to be as strong as the
current thunderstorms. Once the precipitation ends/shifts east
of the area later this morning, dry weather is expected,
however, there is a small chance for some sprinkles or a few
showers this afternoon across northwest IN and did add slight
chance pops for this potential.

High temps today are bit challenging given temps are currently
in the upper 60s/lower 70s and its unclear how much temps may
drop before clouds partially clear and some sunshine may appear
this afternoon. But overall, daytime highs are expected to be
mainly in the lower 70s, perhaps some mid 70s.

Northwest winds will gust as high as 30 mph through sunset and
then quickly diminish. These stronger northwest winds will allow
for building waves along the northwest Indiana shore of Lake
Michigan resulting in dangerous swimming conditions. Current
beach hazard statement remains on track.

The models continue to show an upper trough and surface cold
front moving across the Great Lakes Region on Tuesday. This will
bring a chance of showers and thunderstorms to the area and the
new SPC Day 3 outlook has a level 1 for the potential for a few
strong or severe thunderstorms. Still some uncertainty for
timing and location but current trends support mainly afternoon
and the eastern cwa.

Attention will then turn to Wednesday when the models are
showing the potential for another severe weather event across
parts of the region. While current trends show the best
instability remaining southwest and south of the local area, the
wind fields are quite concerning with low pressure possibly
tracking across northern IL or southern WI. The weaker
instability may be overcome by the stronger wind fields, similar
to an early Spring-like event. In addition, the forecast
precipitable water values range from 1.5 to 2 inches Wednesday.
Despite possibly fast moving storms, torrential rain and
flooding would also be possible.

Models then differ on how much the surface low deepens and how
strong the gradient becomes Wednesday night into Thursday. If
the gradient does strengthen, northwest winds may gust into the
30+ mph range and this would allow for another period of
building waves and dangerous swimming conditions at Indiana Lake
Michigan beaches. cms

&&

.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1227 PM CDT Sun Jun 14 2026

There are no significant aviation weather concerns anticipated
through the period.

The rain has ended across the terminals, but a VFR deck of
strato cu will persist this afternoon before scattering out
towards sunset. Northwest winds will remain breezy this
afternoon, with gustiness of 20-25 kt at times. A lake breeze
will develop this afternoon across southeastern Cook eastward
into northwesterly IN. It remains possible that as the winds
ease towards sunset that this lake breeze makes a run towards
ORD and MDW. Accordingly, there could be a brief period in
which the winds turn north-northeasterly around sunset.
Fortunately, it appears wind speeds would be light and on a
diminishing trend. For this reason, we opted to leave a formal
mention out of the TAF. Otherwise, expect winds to become light
from the west-southwest overnight, then turn westerly around
10-15 kt during the day Monday.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...Beach Hazards Statement until 10 PM CDT this evening for
     INZ001-INZ002.

LM...None.

&&

$$

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