357
FXUS63 KLOT 032301
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
501 PM CST Mon Nov 3 2025

.KEY MESSAGES...

- Seasonably mild, frequently breezy, and dry through midweek.

- The best chance for measurable rain this workweek will be
  late Thursday night into Friday morning.

- Temperatures will turn sharply cooler this weekend into early
  next week.

&&

.DISCUSSION...
Issued at 159 PM CST Mon Nov 3 2025

Through Tuesday Night:

An elevated brush fire danger continues this afternoon with
robust mixing and gusty winds in the wake of this morning`s cold
front. With the abundant sunshine today pushing temps into the
low 60s, RH values have lowered into the 25 to 30 percent range
nearly areawide. Meanwhile, WNW gusts to around 25 mph have been
common, with locally higher gusts closer to the Wisconsin state
line. Winds will diminish beginning late this afternoon with
both the loss of daytime heating and a weakening gradient. Low-
level flow will further weaken this evening with surface high
pressure passing to the southwest.

A small mid-level wave over Utah and embedded within loosely
zonal flow across the central CONUS will quickly track eastward
tonight and cross northern Illinois Tuesday morning. Forcing
with the wave and preceding mid-level WAA should combine with a
ribbon of Pacific-based moisture to generate an axis of mid-
level showers over the area. However, the forcing and mid-level
moisture will outpace more appreciable low-level moisture well
to the southwest. Ultimately, precip at the surface will be
limited to a few sparse sprinkles in the morning. Otherwise,
cloudy skies to start the day will gradually clear through the
afternoon. Similar to this afternoon, southerly gusts to 25 mph
and RH values falling into the 25 to 30 percent range in the
afternoon will result in elevated brush fire danger again.

Another low with associated showers will pass well north of the
area late Tuesday night. Breezy southwest winds will yield a
seasonably mild night under partly cloud skies.

Kluber


Wednesday through Monday:

Another surface low will move eastward across the Great Lakes
on Wednesday. The attendant cold frontal passage continues to
look dry here locally, but this system will drive yet another
increase in northwesterly breezes during the daytime on
Wednesday. High pressure will briefly build in across the region
Wednesday night/Thursday morning, but this will be short-lived
as the next area of low pressure develops near or over the
Minnesota Arrowhead and subsequently shifts across the northern
Great Lakes into Thursday night. Guidance continues to suggest
that this system will have a bit more moisture to work with,
leading to a blossoming area of showers, and perhaps some
embedded/isolated thunderstorms Thursday night/Friday morning.
Yet another period of breezy northwesterly winds will occur on
Friday as the aforementioned low scoots through the region.

While the spread in ensemble guidance increases quite a bit
heading into the upcoming weekend, there`s a signal for an
additional round of cyclogenesis in the vicinity of the remnant
baroclinic zone left over from the repeated cold frontal
intrusions. Just how this low development evolves remains
unclear at this range, but an additional period of precipitation
appears plausible over the weekend. There`s also a smattering
of guidance that suggests that a transition to some snow could
potentially be in play, though have continued to limit the
mention of this possibility in the gridded forecast given the
existing uncertainties this far out. Regardless of this system`s
evolution, there is a strong signal that a much colder air mass
will shift into the area with a hard freeze for many areas
Sunday night and highs possibly struggling to make it out of the
upper 30s on Monday.

Carlaw/Ogorek

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 501 PM CST Mon Nov 3 2025

Light west winds will prevail through the overnight and morning
hours. High clouds will pass overhead through the morning hours
as a moisture-starved and weakening system slings overhead. As
high clouds thin toward noon, mixing heights should build
sufficiently to allow a few wind gusts up to about 20kt out of
the southwest. In all, the next 24 hours look relatively quiet
from an aviation perspective.

Tomorrow evening, surface decoupling will encourage winds to
back toward the southeast (wind direction 170 or so). The wind
direction should veer back southwesterly with time as a strong
low-level jet develops overhead. LLWS criteria will be met by
the end of the 30-hour TAF window at ORD/MDW as flow at 2kft
reaches 45 to 50kt.

Borchardt

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory until 5 PM CST this afternoon for
     Winthrop Harbor IL to Gary IN.

     Small Craft Advisory until 10 PM CST this evening for Gary to
     Burns Harbor IN-Burns Harbor to Michigan City IN.

&&

$$

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