Four Corners, Iowa Weather Forecast Discussion

008
FXUS63 KDVN 061021
AFDDVN
Area Forecast Discussion
National Weather Service Quad Cities IA IL
521 AM CDT Mon Oct 6 2025
...Updated for 12z Aviation...
.KEY MESSAGES...
- A cold front will bring showers (40-70%) and a few storms to
  the area through tonight. The greater coverage is anticipated
  later today and especially tonight. This will not be a
  drought-busting rain, but our best chance in nearly 2 weeks at
  a wetting rainfall of 0.1 inch or more with pockets of 0.5+
  inches possible.
- Cooler, more seasonable early fall temperatures settle in over
  the next 24 hours and persist into late week.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 240 AM CDT Mon Oct 6 2025
Large footprint of banded showers and some storms is noted this
morning immediately behind a cold front extending from eastern
WI through central IA and southwest KS. A rainy cold front is
usually an anafront, and that is the case this morning and bodes
well for bringing our best chance at seeing measurable rain
since Sept 23rd. In true anafront characteristics the rain/cloud
shield is largely rooted behind the front and extends westward
to the 850 hPa boundary. The initial shower activity has
struggled to make much inroads into the service area due to
drier air and waning low level Fgen. However, a more robust mid
level Fgen band was organizing to our southwest from parts of
southwest IA, southeast NE into KS and models track this Fgen
band into our neck of the woods later this morning, so we should
see some expansion or uptick of shower activity after daybreak
through midday, particularly in areas north/west of the Quad
Cities. We may see then a bit of a lull with some potential for
pre-frontal scattered showers and a few storms this afternoon
in parts of far eastern Iowa and particularly northwest
Illinois, but confidence is somewhat low due to weak forcing and
will be dependent largely upon sufficient destabilization in
what looks to be a generally uncapped environment. Wouldn`t rule
out some gusty winds and possibly small hail (similar to what was
observed yesterday evening to our west) should any storms occur
given ramping deep layer shear. Synoptic scale ascent will
increase tonight attendant to the right entrance region of an
upper level jet streak atop the surface cold front. This should
bring about a greater coverage of showers and possibly a few
storms this evening/overnight before tapering off early Tuesday
morning. Rainfall will be mostly under 0.25 inch, but some pockets
of 0.5-0.75+ inch are possible as hinted by 00z HREF 24 hr
Localized Probability Matched Mean (LPMM) ending 12z Tuesday with
PWATs climbing to 1.3 to 1.5 inches. This will not be enough to
bring any drought relief, but it should help in knocking down the
dust and putting a little moisture back into the plants.
High temperatures today will of course be very challenging with
the boundary slowly progressing through the area. What is
certain is that the coolest readings will be found in our
northwest service area (greater coverage of showers and clouds)
while the warmest readings will be in our east/south (longer
duration of solar insolation). Some of the guidance supports
potentially a 25 to 30+ degree gradient with readings possibly
as cool as the upper 50s to lower 60s northwest and as warm as the
mid 80s south/east. As typical the greatest challenge with
highs will reside near the front and right through the heart of
the service area.
Tonight we`ll begin to shut down the rain from north to south
late as the cool air deepens. Skies may correspondingly begin
to clear as well leading to cool lows in the 40s to around 50
north, while clouds and some rain chances linger through
daybreak south resulting in lows holding up in the middle 50s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 240 AM CDT Mon Oct 6 2025
A west-northwest flow pattern aloft is expected to dominate
through the end of the work week, while at the surface high
pressure shifts across the Great Lakes. This will bring a very
refreshing and pleasant airmass on easterly flow with mainly dry
conditions and seasonable early fall temperatures with highs in
the 60s/70s and lows in the 40s/50s. Models do suggest some
upper level energy may work down across the region toward
Thursday into Friday, resulting in some low chances for showers.
However, dry low level easterly flow lends to very low confidence
on this potential.
Over the weekend, the ensembles generally support amplification
of an upper ridge over the region. This should foster a nice
warmup back above normal on temperatures with highs once again
in the 80s.
&&
.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 515 AM CDT Mon Oct 6 2025
Cold front has just passed CID and DBQ. Increasing mid level
frontogenetical forcing post-frontal will bring about an uptick
in showers this morning in the vicinity of both sites with
conditions lowering into lower VFR and MVFR with a low chance of
IFR. The front will take until late morning and afternoon to
pass through MLI and BRL. Until it does, VFR conditions will
abound. As it approaches there is a 20-30% chance for a few
showers and storms pre-frontal at both MLI and BRL. Tonight,
anticipate an increase in shower coverage across all terminals
with synoptic scale lift increasing attendant to an upper level
jet atop the sagging frontal zone, with conditions mainly lower
VFR to MVFR with spotty IFR. After 06z/07 the rain will gradually
taper off from northwest to southeast through 12z followed by
decreasing clouds/VFR conditions.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...McClure
LONG TERM...McClure
AVIATION...McClure

NWS DVN Office Area Forecast Discussion