968
FXUS63 KLOT 250225
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
925 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 /00Z TAFS THROUGH 06Z MONDAY/...
Issued at 613 PM CDT Sat Oct 24 2026

Quiet VFR aviation weather conditions will persist through the
period. Winds are becoming light southeast with sunset, and will
remain generally southeast through the night. Winds will likely
become light south (~5 kt or less) pre-dawn, then shift south-
southwest to southwest (190-210 deg) just under 10 kts after
sunrise.

Patchy mid/high level VFR clouds will linger across the area
through Sunday.


Ratzer

&&

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

&&

$$

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