Aurora, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

148
FXUS63 KLOT 192309
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
509 PM CST Fri Dec 19 2025

.KEY MESSAGES...

- After a see-saw in temperatures this weekend, a substantial
  warming trend will take hold next week, particularly for
  Christmas Day.

&&

.DISCUSSION...
Issued at 239 PM CST Fri Dec 19 2025

Through Saturday:

With some mid-level cloud cover and even some virga spreading in
from the west and northwest as of this writing, not expecting
much of a temperature drop this evening from current readings
(maybe a 1-2 degrees in spots after sunset). For the rest of
tonight, the next strong shortwave will track near the far
Northern Plains-Canadian Prairies border while surface high
pressure settles into the eastern Ohio Valley. A stout low-based
low-level jet may be able to punch occasional gusts through the
near-surface stable layer amidst otherwise gradually increasing
southerly winds. Temperatures will more markedly rise overnight
in response to the south winds and cloud cover.

After sunrise Saturday, there should be an increase in wind gust
frequency (25-30 mph) from mixing into the base of the departing
low-level jet. This will also help temps steadily warm to the
upper 30s-lower 40s by midday. A cold front trailing from far
northern Great Lakes low pressure will sweep across the area in
the midday-early afternoon timeframe and bring an end to the
brief milder temps, with falling temps towards sunset.
Precipitation wise on Saturday, the southern periphery of the
shortwave passing to our north will be associated with decent
large scale ascent. However, with the exception of a few outlier
and previous CAM solutions, the sub-cloud layer looks generally
too dry to support any measurable precip. Can`t rule out a few
flurries/light snow showers (15-20% PoPs) near the WI border for
a couple hours (roughly between 10 AM and 1 PM).

Castro

Saturday Night through Friday:

Seasonable to slightly below normal temperatures Saturday night
into Sunday (lows in the teens and highs in the upper 20s-lower
30s) under expansive ~1035 mb surface high pressure will be the
last bout of typical winter cold until perhaps next weekend.

Monday onward, anomalous upper-level blocking south of Alaska will
facilitate aggregate troughing along Pacific Coast, enabling a broad
region of quasi-zonal flow generally centered along the US/Canadian
border. With the mean position of the upper-level jet to our north,
the stage will be set for a prolonged period of above-average
temperatures. Highs are expected to rise 5 to 7 degrees each day,
starting in the upper 30s to lower 40s on Monday rising to the
50s and 60s (!) by Christmas. It`s too far out to confidently
predict record warmth being threatened on Christmas Day, but the
signal has remained strong enough for multiple model cycles that
it will remain an item of interest.

Chances for precipitation next week will be tied to WAA-
regimes ahead of passing upper-level shortwaves embedded in the
quasi-zonal flow centered to our north. At this point, am
seeing two windows to watch for such WAA-driven precip, with the
first Sunday night into Monday and the second Christmas Eve
into Christmas.

With the first window (Sunday night into Monday), low-level
temperature profiles would be supportive of light snow ending as
a wintry mix as the precipitation type. However, forecast
soundings depict a notable pocket of dry air near the ground,
which may end up limiting any precipitation from occurring. With
the latter (Wednesday night into Thursday), a more formidable
push of low-level moisture (dew points rising into the lower
50s) may lead to fairly damp conditions characterized by drizzle
and intermittent showers. At this point, the sliver of slight
chance PoPs over the northeast 1/4 of the CWA Sunday night-
Monday and 20-40% PoPs centered on Christmas Eve appear
reasonable for now.

Castro/Borchardt

&&

.AVIATION /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 509 PM CST Fri Dec 19 2025

Key Aviation Messages for the current TAF period:

- Low level wind shear (LLWS) is expected overnight

VFR conditions are expected through the TAF window. Winds
remain around or just under 10 knots this evening, but are
slowly becoming more southerly. After midnight, a low level jet
will ramp up to almost 60 knots above 2000 AGL. Surface winds
will remain out of the south, but the jet will be out of the
southwest. There is lower confidence in prevailing surface gusts
through the night, but there was enough of a signal to keep it
in the TAF.

Surface winds will become more west-southwesterly in the
morning. While the low level jet is expected to subside and end
the risk for LLWS, better mixing should allow for surface gusts
to continue into the early afternoon. Winds should diminish by
late afternoon. There could be a brief window of northwesterly
directions after 00Z, but should return to the west-southwest
through tomorrow evening.

DK

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory from midnight tonight to 4 AM CST Sunday
     for Winthrop Harbor IL to Gary IN.

     Small Craft Advisory until 6 PM CST this evening for Gary to
     Burns Harbor IN-Burns Harbor to Michigan City IN.

     Small Craft Advisory from midnight tonight to noon CST Sunday
     for Gary to Burns Harbor IN-Burns Harbor to Michigan City
     IN.

&&

$$

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