Crystal Lake, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

091
FXUS63 KDVN 150745
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
245 AM CDT Wed Oct 15 2025

.KEY MESSAGES...

- Passing system will bring light precipitation to locations
  north of Interstate 80, with those south likely to remain dry.

- After today, we will start to see the temperatures increase to
  above seasonal norms again. We may see the low 80s return to
  the area on Friday.

- A larger system will pass through the Upper Midwest Friday
  night through Saturday, bringing the potential for widespread
  rainfall and embedded thunderstorms. No severe weather is
  expected at this time.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 238 AM CDT Wed Oct 15 2025

An upper ridge remains situated over the Upper Midwest, with another
bout of energy passing through the flow along the ridge. This will
bring through chances for more isolated-scattered showers through
the day today. The best forcing moves into the area this morning and
into the early afternoon, which we opted to add in slight-chance
PoPs again through the day to message the chance. Similar to
yesterday, this will be another low QPF event, with expectations
being <0.10". We are expecting this to move through the area as
light rain and/or drizzles. This activity will be focused in
areas along/north of Highway 30, with infrequent showers
possible down towards Interstate 80. Areas south of there
should remain largely dry, aside from some possible drizzles.
Although, many will continue to see a sky full of clouds again,
with better chances for breaks in the clouds south of Interstate
80. Thus, it will be another gloomy/cloudy day for most of the
area. Temperatures will range widely again, with low 60s in our
north to mid-upper 70s in our south.

Tonight, we will start to see this system slowly move out of the
area. Although, we will not see much of a change, aside from
decreasing clouds from the south. Areas in our north may continue to
see some light rain or drizzles, resulting from better saturation
and weak forcing nearby. Temperatures will moderate in the mid 50s
for most tonight, owing to the residual cloud cover.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 238 AM CDT Wed Oct 15 2025

Upper ridge will remain overhead through the remainder of the work
week, with a deepening wave over the Rockies. This setup will usher
in llvl southwesterly flow for the end of the week, with the bulk of
the warm advection moving in on Friday. Not only will this increase
moisture throughout the area, but well above normal temperatures
will move in once again. Granted, we are not talking oppressive
heat. Normal temperatures during this time of the year are in the
low 60s, with us currently forecasting mid-upper 70s and low 80s for
some on Friday!

Deep wave ejects off of the Rockies Friday into Saturday, passing
northeast through the Upper Midwest. This will push the ridge east
of the area Friday into Saturday, dragging a cold front through the
area Saturday. While the overall picture remains the same, guidance
has trended slower, with rain not moving in until later Friday
evening/night. From there, the cold front will be slower to move
out, keeping PoPs over much of the area through the day on
Saturday. This system is expected to bring much needed rain to
much, if not all, of the area. Heavy rain is not expected.
Rather, we can expect a nice soaking rainfall, with generally
<0.50" expected. Some guidance hints at more rainfall, but
confidence remains low at this time. Given how dry it has been,
this will we a welcome sight. Some embedded thunderstorms will
be possible as well. Severe weather is not expected at this
time, with better forcing and environment for such south of the
area. Behind this cold front, we are in for quite the change on
Sunday. Sunday will feature seasonal temperatures and
breeziness, with mostly clear skies. So, while that will be
normal for the time of the year, it will feel starkly different
than the above normal temperatures that we have been seeing.
Warmer clothing might be necessary, especially during the
evening/night.

Beyond the weekend, the pattern looks to remain relatively active.
Thus, temperatures will be up and down through the upcoming work
week. Although, there remains some uncertainty overall due to long
term guidance not being in agreement on the overall pattern. CPC
guidance favors above normal temperatures once again, with low-end
favorability for above normal precipitation. Too soon to pinpoint
when the next best chance for precipitation will be beyond Friday
night and Saturday, but there are sporadic low-end chances through
next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1222 AM CDT Wed Oct 15 2025

A system continues to pass through the Upper Midwest, which will
bring along brief periods of MVFR cigs tonight at CID and DBQ.
MLI and BRL should remain dry with cigs between 3500-5000 ft,
but DBQ/CID may see on and off light rain/drizzles, which may
bring along lower cigs. Best chances will be through the
morning, after 12z. Cigs may drop down to 1500-2500 ft at times,
with higher confidence in this at DBQ. This will be covered with
a PROB30 group for now, as there still remains some uncertainty
on timing and coverage. Otherwise, winds will remain largely
easterly around 10 KTs.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.

&&

$$

SHORT TERM...Gunkel
LONG TERM...Gunkel
AVIATION...Gunkel