180
FXUS63 KLOT 250456
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1156 PM CDT Sat Oct 24 2026

.KEY MESSAGES...

- Generally well above normal temperatures will continue, albeit
  with a modest cool-down on Monday near and north of I-80, and
  particularly near Lake Michigan.

- There are periodic low/uncertain rain chances in the mid to
  late workweek period, with the best chance of any meaningful
  rainfall not until next Saturday (Halloween) night.

&&

.UPDATE...
Issued at 925 PM CDT Sat Oct 24 2026

No significant changes to the forecast this evening. Only item
of note is an area of weak radar returns along the IL/WI border
northwest of Rockford at this time, associated with high-based
(15-20 kft) sprinkles/showers on the tail end of a mid-level
speed max tracking across WI. 00Z DVN RAOB depict moisture above
~650 mb, coincident with relatively steep mid-level lapse rates
of ~6.5 C/km. Farther to the south, ILX sounding displays
weaker saturation and less favorable wind profiles. Deep layer
of drier air below the mid-level cloud deck suggests the mid-
level sprinkles indicated by these radar returns are very
unlikely to reach the ground across far northern IL (though some
light rain may reach the surface in spots across southern WI
over the next few hours).

Ratzer

&&

.DISCUSSION...
Issued at 225 PM CDT Sat Oct 24 2026

Tonight through Sunday:

Following a calm, cool, and partly cloudy night tonight
(relative to this afternoon`s warmth), Sunday has a decent
chance to be one of the warmest days of this current stretch.
Mid and higher level cloud cover may limit temps from really
overperforming, though currently expecting enough sun for
widespread mid 70s highs away from the immediate Illinois shore.
Localized upper 70s readings are plausible, especially over
southwestern sections of the CWA (ie. in/near Pontiac).

Sunday Night through Saturday:

A backdoor cold front will move across the area Sunday night,
knocking temps down vs. the weekend for Monday`s highs, but
still above average for late October. The coolest readings
(around 60F/low 60s) will be found near Lake Michigan due to
strengthening north-northeast winds. Expansive surface high
pressure over the region on Monday night will likely yield the
coolest night of the week (still solidly above normal for late
October).

Tuesday will warm back to farther above average, followed by
another period of well above average temps (highs approaching
80F in spots?!) centered on midweek. Chances for rain mid to
late next week, while not zero, are low/nebulous, and the best
chance for anything of note looks to be confined to primarily
west and north of the local area. If a weakening cold front is
able to push south across at least the northern half of the area
Thursday-Thursday night, that would result in lower temps than
in the official forecast (especially near the lake).

There has been a more consistent signal for a stronger synoptic
system or two over the second half of next weekend into the
following workweek. First a warm front will lift north Friday-
Friday night, giving way to what may shape up to be one of the
warmest Halloweens in years. For trick or treating interests,
while the official forecast advertises the arrival of low rain
chances during the day on Saturday, the ensemble consensus
favors late Saturday night into Sunday for widespread rainfall.

Castro

&&

.AVIATION /06Z TAFS THROUGH 12Z MONDAY/...
Issued at 1156 PM CDT Sat Oct 24 2026

Quiet weather continues with VFR conditions persisting into
tonight. Light southeasterly winds overnight will turn south-
southwesterly shortly after daybreak this morning, but speeds
will remain under 10 kt during the day. Winds will ease to 5 kt
or less this evening in advance of an approaching cold front.
This cold front will shift across the terminal airspace during
the predawn hours of Monday morning, resulting in a north-
northeasterly wind shift. We will also have to keep an eye on
the potential for a period of IFR CIGs with the passage of this
front early Monday morning. For the current set of 30 hour TAFs
for ORD and MDW I did include this northerly wind shift after
10Z Monday morning. I also hinted at the possibility of some
lower clouds (SCT008) around in the wake of this frontal
passage.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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