Des Moines County Iowa Weather Forecast Discussion

673
FXUS63 KDVN 141934
AFDDVN
Area Forecast Discussion
National Weather Service Quad Cities IA IL
234 PM CDT Tue Oct 14 2025
.KEY MESSAGES...
- Spotty mainly light showers will continue off an on across the area
  through Wed night, with the better coverage shifting along
  and north of Interstate 80 by later tonight.
- Clouds and seasonably mild Temperatures through mid week, with
  a good warm up still looking on track for Friday with some
  having a chance for low 80s.
- A larger system and stronger front will pass through the Upper
  Midwest Friday night through Saturday, bringing the potential
  for widespread rainfall and embedded thunderstorms.
&&
.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 235 PM CDT Tue Oct 14 2025
The latest sfc analysis was indicating the main quasi-
stationary front was draped acrs the central plains up through the
southeastern GRT LKS, while aloft broad omega ridging occupied much
of the south central half of the CONUS. This set up with ridge-
riding waves will continue to make clouds and spotty showers acrs
the local area tonight into early Wed. Initial showers having
trouble saturating the LLVLs this aftrernoon with most just
sprinkles or virga aloft, but they are making headway acrs the
western and northwestern CWA ATTM.
But as the upstream large upper low/wave pulls out acrs the north
central Rockies putting a squeeze on it, the ridge lobe will sharpen
and amplify acrs the area through Wed night. In the process, the
vort max and related shower activity will start to get shunted in
higher coverage more to the north of I80 overnight into Wed morning,
and eventually to the west and northwest of the area Wed night, with
maybe an WAA wing of elevated showers and possibly an isolated storm
making its way into the northwestern CWA toward early Thu morning.
Higher based MUCAPES are progged to range 100-200+ J/kg in our
northwest and north into Thu morning suggesting a flash possible,
but mid level lapse rates marginal at best. QPF amounts light
through the period under a tenth of an inch for those who manage to
get some precipital activity.
As for temps in the short term, tonights lows ranging from the lower
50s north, to the low 60s south. Wed highs a challenge with cloud
cover and mixing depth issues. Taking into account the time of year
will side with a cooler blend output with highs ranging from the low
60s in the northeast, to the mid 70s south. Lows generally in the
50s again Wed night.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 235 PM CDT Tue Oct 14 2025
Thursday and Friday...Rather sharp upper ridge continues to adjust
eastward acrs most the length of the MS RVR Valley at the start of
this period, with a 20-30 KT H85 MB southerly LLJ taking over most
the area by Thu evening. We still may have lingering WAA clouds and
a wing of elevated precip acrs the north in the morning, but that
should continue to retreat north and possibly flare up diurnally
with the increasing jet just to the north of the local CWA. That
would leave us in an increasing warm sector but fcst soundings show
varying amounts of inversion growth with the WAA(warm air advection)
aloft and how deep we mix and warm up still a challenge at this
point. Some worry the loaded blend may be too warm if we don`t mix
to at least H875 MB, especially in the north. Same with Friday and
the chance for some WAA AC clouds, otherwise vertical thermal
profiles support highs in the upper 70s to low 80s and breezy
conditions for Friday with a decent mixing depth.
Friday night, the latest ensembles continue to show a digging longer
wave upper trof aided by robust horse-shoeing upper jet complex acrs
the plains and MO RVR Valley. Timing and progression of an
associated stronger cool front through the area still a challenge,
but an ensemble blend shows midday Saturday. Precursor warm and more
moist conveyor to fuel a stream of showers and some embedded thunder
up acrs the local area later Friday night into Saturday morning with
the latest accepted timing. Dry air to overcome and initial PWAT
feed advertised would support rainfall amounts of 0.25 to around a
half inch by mid Sat morning in much of the area, but again this is
uncertain and lower confidence at this juncture in time.
Saturday through Monday...Looking at the same latest suite of
ensemble runs, conceptional strong synoptic scale dynamics and
thermodynamics interplay for a second season severe weather out
break Saturday acrs the Ozarks of AR and MO into southern IL. The
latest NCAR medium range convective hazard fcsts for this day hi-
lighting much of the same area. Will have to watch for a northward
migration in additional runs possibly closer to the southern CWA, but
for now the nasty wx index stays off to the south. Lingering showers
an a few storms possible on Sat along with mild temps, before the
main cool push sweeps in from the northwest as the upper trof axis
edges close later Sat night. Sunday looking like a blustery and much
cooler post-frontal day, more autumn-like with highs in the 50s to
low 60s. Longer range upper jet patterns suggest another building
upstream upper ridge to get shunted acrs the mid and upper MS RVR
Valley by early week in a more dynamic but progressive northeast
Pacifc-into-the CONUS pattern. Of course this would mean another
unseasonable warm up for Monday into Tue with a looming cyclone off
to the west or northwest.
&&
.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1245 PM CDT Tue Oct 14 2025
With a frontal system stalled off to the south of the area, most
of the TAF sites will be subject to low VFR to MVFR CIGs and
spotty passing light showers through Wednesday morning,
especially CID and DBQ. There is a chance that BRL will stay dry
and VFR through midday Wed, and MLI in the middle. Generally
east to northeast sfc winds will maintain north of the front at
6-10 KTs through the TAF cycle as well.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...12
LONG TERM...12
AVIATION...12

NWS DVN Office Area Forecast Discussion