259
FXUS63 KDVN 271108
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
608 AM CDT Tue Oct 27 2026

.KEY MESSAGES...

- Unseasonably mild fall weather continues through the end of
  the week with passing clouds and relatively light winds.

- Precipitation chances increase late this week and into early
  next week as a more active pattern takes shape.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 1249 AM CDT Tue Oct 27 2026

A weak low pressure over Minnesota will lift a boundary
northward today as southerly flow returns to the area. A passing
trough could spawn some isolated rain showers (10% coverage)
near the I-380 and Highway 20 corridors in Iowa, but dry low
levels will keep this a non-wetting rain if it reaches the
ground. Highs once again climb back into the low 70s this
afternoon. Heading into tonight, shortwave ridging builds back
in, drying out the CWA. The persistent southerly flow will put a
floor on radiational cooling with lows only in the upper 40s
and low 50s.

On Wednesday, a negatively tilted trough over south-central
Canada will develop a low pressure system with a cold front
extending southward into the Northern Plains. This front is
expected to work its way into Iowa Wednesday night, bringing a
better chance for showers and even storms (30-80%; highest
coverage in eastern Iowa). Conditions dry back out on Thursday
as the cold front slides into central Illinois and northern
Missouri and a weak high pressure propagates into Minnesota and
Wisconsin. Northeasterly flow behind the front will provide a
quick shot of cooler air for areas north of I-80.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Issued at 1249 AM CDT Tue Oct 27 2026

Thursday Night-Sunday...A subtle trough in the subtropical jet
is forecasted to move into Southern Plains Thursday night into
Friday, causing pressure falls along the Front Range in
Colorado. As zonal flow aloft turns southwesterly, the cold
front from Thursday will transition into a warm front and move
northward. Scattered showers and storms (40-80% coverage) are
likely to develop along this boundary Friday into Saturday
morning. By Saturday, the trough reaches Iowa and northern
Missouri, keeping PoPs (40-60%) on the board heading into
Sunday. Rainfall totals of 0.1 to 0.5 inches are probable
(70-90% chance) areawide through Sunday.

Early Next Week...Longwave troughing over the western CONUS is
expected to become in phase with the subtropical jet and eject
eastward into the Rockies. Surface cyclogenesis is likely across
the Central Plains with a warm front extending eastward into
the Mid-Mississippi River Valley. Beyond this point, there is
great uncertainty among the ensemble guidance in the development
of this mid-latitude cyclone and its path, but confidence is
high (70-90% chance) on a wet and breezy pattern early next
week.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 604 AM CDT Tue Oct 27 2026

Dry low level through mid level air will keep our area VFR and
dry today, though like the past few days, high clouds will be
moving through. Visibility will be excellent today at main
terminals, and any restrictions at smaller airports will be due
to harvesting activities today. Southeast winds around 7 kts
will become more southerly by late morning today, and remain
5-10 kts through tonight.

&&

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

&&

$$

SHORT TERM...Delaune
LONG TERM...Delaune
AVIATION...Ervin