276
FXUS63 KDVN 252307
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
607 PM CDT Tue Aug 25 2026

...Updated for 00z Aviation...

.KEY MESSAGES...

- Cold front passing through the area tonight to bring isolated-
  scattered showers/storms into Wednesday morning, diminishing
  by the afternoon.

- Stretch of dry and seasonal weather will continue through the
  remainder of the week.

- Pattern to become more active late this weekend and beyond,
  with shower/storm chances increasing into next week.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 216 PM CDT Tue Aug 25 2026

Ahead of an approaching cold front, we will see a dry evening and
night for the most part. Although, subtle warm advection in the
llvls and increasing cloud cover will help keep temperatures a
little milder than the previous night.

Weak upper wave to pass through our area late tonight through
Wednesday morning, dragging a weak cold front through the area.
Short term guidance would favor the cold front making it into our
far northwest just after midnight tonight. Moisture will remain
quite limited, largely exhibited through passing clouds along the
front. Although, there will be the chance for isolated showers along
the cold front, where best moisture will pool, along with the better
forcing. Confidence is low on coverage of showers, with several
CAMs keeping us dry. Thus, there is a better chance that some
locations may remain dry as this front passes through.
Confidence in overall precipitation chances is low, generally
ranging between 15-30%. If the front comes through slower than
anticipated and passes through some of our area tomorrow
afternoon, there will be a low-end severe threat. Although,
guidance favors a quicker frontal passage, keeping the severe
threat southeast of the area. The SPC has since shunted the
Marginal Risk, level 1/5, southeast of the area, barely
highlighting parts of southeast Putnam County Illinois now.
Thus, they are also catching onto the decreased potential for
strong/severe storms at this time for our area.

Tomorrow night, a post-frontal airmass will move in with cool/dry
advection. Temperatures will cool into the low-mid 60s, with mostly
clear conditions and light northwest winds. Drier air advecting in
should help limit any fog potential at this time.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 216 PM CDT Tue Aug 25 2026

Thursday into Saturday, upper ridge over the Central CONUS will
continue to slowly shift easterly and flatten out due to waves
passing through the north. This will result in a period of surface
high pressure, leading to quiet and seasonal weather.
Temperatures will remain in the 80s, with lower humidity and
mostly clear skies. Winds will also remain light and variable
through this timeframe, bringing quite the pleasant end to the
work week.

Saturday and beyond, the upper ridge finally gets pushed east of the
area. This shift in the pattern would guide llvl southerly to
southwesterly flow into the region, allowing for temperatures and
humidity to increase. Upper level flow will generally be zonal to
southwesterly as well, which will put us under the path of passing
shortwaves. Thus, if this pattern holds true, it would seem like we
are heading into a potentially active stretch of weather late this
weekend and into next week. Global models are in general agreement
on chances for precipitation, with some differences in the timing
and track of these shortwaves. Thus, some things will need to get
ironed out as we get closer. Although, NBM does introduce daily PoPs
(20-40%) Sunday into the middle of next week. Too soon to determine
any severe threat.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 555 PM CDT Tue Aug 25 2026

Predominantly VFR conditions anticipated through the TAF cycle.
A cold front will move across the terminals 06z-15z bringing a
shift in winds from SSW to NNW. Isentropic ascent may foster
some spotty shower activity along the front, with the signal
for the better chances still favoring the Hwy 20 corridor. Thus,
will maintain the PROB30 mention at KDBQ and leave out elsewhere
for now. Can`t rule out some patchy fog and lower stratus (low
MVFR to IFR conditions) in the wake of the frontal passage, but
NBM probabilities for visibility <5sm is just 20-30% and for
CIGs <3kft is 15-30% with the main signal albeit low also near KDBQ.
For now with lower confidence I have only hinted at this potential
with 6SM visibility and a scattered stratus deck. SC/CU is
expected on Wednesday in the cool advection with any bases
lifting to VFR prior to 18z. NNW winds will become sustained at
around 10 kt with gusts around 20 kt after 15z through the rest
of the period, similar to what is occurring across the dakotas
and western MN today post-frontal.

&&

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

&&

$$

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