560
FXUS63 KDVN 171741
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1141 AM CST Mon Nov 17 2025

...18z Aviation Update...

.KEY MESSAGES...

- Cloudy skies will eventually lead to scattered showers and
  possibly even a thunderstorm up across the area by tonight.

- After a midweek lull, and active pattern returns for the late
  week ahead.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 152 AM CST Mon Nov 17 2025

Warm advection has already spread mid clouds over our CWA early this
morning, helping hold temperatures in the mid 30s to lower 40s under
the clouds, while we fell to the upper 20s to low 30s in the east
prior to midnight. Cloud cover will be the primary driver of how
temperatures work out today.  Given the rather continuous WAA aloft
today, since cloud cover is already resulting from this, I`m
inclined to believe we`ll see mainly cloudy skies today, which
supports holding temperatures towards the cooler 25%NBM, which is
mid/upper 40s north to low 50s central, and some mid 50s in the far
south.

Through the day, mainly dry conditions are expected, but by early
evening, the approaching mid level wave will bring stronger lift in
the early evening and over overnight. While models are different
with MUCAPE, most of the CAMs have 200-800 J/kg tonight, mostly in
the Interstate 80 and south. Thus, we`ll continue the isolated
thunderstorms in our forecast, which will allow some located QPF to
be over 0.25", while many other places will see around 0.10 or less.
The widespread light rain will lead us to be high pops, with 60-90%
tonight, despite the light QPF.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 152 AM CST Mon Nov 17 2025

Tuesday, the system will be overhead in the morning, the moving off
to the east in the afternoon. The depth of moisture appears to dry
off above 5Kft Tuesday morning, with saturation continuing near the
surface as the low moves overhead.  While some CAMs continue with
showers in this period, this appears to hinting that drizzle and fog
are a growing potential Tuesday morning. Tuesday will be another
cool day, with plenty of clouds, dampness, and highs in the 40s for
most places.  Like today, the 25%NBM appears to be the preferred
temperatures. Saturated temperatures above freezing near the surface
up through 7kft, should keep precipitation liquid through the event.

Wednesday continues to appear to be a break in the action this week,
with clouds likely a problem for temperatures, which could be the
second day of stratus in place, all be it with dry conditions.

Thursday through Friday remain in question now, with deterministics
continuing to vary from a brush of cold rain in our far south, GFS,
or a wet CWA rain event over 0.50" on the EC.  WPC has shifted
probabilities of 0.5 south of earlier forecast, but continues to
offer 0.25 to 0.5 in this period for areas south of I-80. This seems
a nod towards the 12z/16th EC solution, and about 1/2 of the
00z GEFS members, which all bring the upper low up into the
Midwest. This remains a period where change could impact our
forecast, given the wide variance in the upper level flow
forecasts for that late week system (both a dry period and wet
possible locally, which is why our pops remain under 60%).

Temperatures generally appear in the upper 40s to lower 50s for
highs most days of our forecast, with the exception of Thursday,
where WAA is expected to bring 50s to lower 60s to the region for
high. Low temperatures remain in the lower 30s for most periods of
the forecast this week, except for Wed night and Thu night which are
milder in the mid 30s to lower 40s.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1138 AM CST Mon Nov 17 2025

Mid and high clouds with a VFR TAF period into this evening,
before higher based showers develop and spread northeastward
acrs the area this evening and into the overnight. Some isolated
thunderstorms possible embedded in the showers, but will hold
off mention in the TAFs for now. The rain and some light fog
may reduce conditions to MVFR at times this evening, but it may
be mainly VFR until after midnight when top-down saturation
produces lowering CIGs into Tue morning, possibly to IFR levels
especially in the north. The showers will look to decrease late
tonight or into early Tue morning, trending to light rain or
drizzle with some fog by Tue morning. Only BRL may improve with
CIGs by late morning, but low confidence in this.

&&

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

&&

$$

SHORT TERM...Ervin
LONG TERM...Ervin
AVIATION...12