355
FXUS63 KILX 011048
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
548 AM CDT Sat Nov 1 2025

.KEY MESSAGES...

- The next chance for widespread rainfall will materialize by
  Thursday night into Friday as a cold front swings through the
  region.

&&

.SHORT TERM...(Today through Sunday)
Issued at 310 AM CDT Sat Nov 1 2025

An upper-level low evident on 0730z/230am water vapor imagery over
Iowa will pivot southeastward across the area today. Skies will
initially be partly to mostly sunny early this morning:however,
as the low comes overhead and mid-level lapse rates steepen
substantially, skies will become mostly cloudy by afternoon.
Isolated showers will develop during peak heating, especially
along/west of the I-55 corridor. As has been noted by the past few
model runs, the deepest moisture will exist on the S/SE periphery
of the low from the Ozarks into the Ohio River Valley. As a
result, higher rain chances will focus along and south of the I-64
corridor this afternoon. Thanks to the increased cloud cover,
high temperatures will remain in the upper 40s west of I-55...but
will reach the lower to middle 50s east of I-57 where partial
sunshine will persist longest. The low will quickly shift
southeastward out of the region tonight, with just a few showers
persisting south of I-70 into early evening. Once the system exits
and skies partially clear, a very chilly night will be on
tap...with lows mostly in the upper 20s and lower 30s. Despite a
return to sunny skies, highs on Sunday will remain slightly below
normal for this time of year in the middle 50s.

Barnes

.LONG TERM...(Monday through Friday)
Issued at 310 AM CDT Sat Nov 1 2025

Quiet weather will prevail through much of the extended forecast
with temperatures climbing back above seasonal normals into the
middle to perhaps upper 60s Tuesday through Thursday. After that,
a cold front is progged to bring the next chance for widespread
rainfall by late Thursday into Friday. 00z Nov 1 GFS/ECMWF/GEM are
all in excellent agreement with the speed of the front...with all
solutions pushing it into the Illinois River Valley by early
Friday morning...then into Indiana by late afternoon. Southwesterly
flow ahead of the approaching front will bring better deep-layer
moisture northward into the region, resulting in higher confidence
in precip development. Due to good model agreement, have opted to
raise PoPs to 40% across the board. Thanks to surface dewpoints
climbing into the middle to upper 50s, GFS MUCAPE values increase
to 400-600J/kg along/west of I-55 Friday morning...then to
600-900J/kg east of I-55 during the afternoon. A quick glance at
the NSSL Machine Learning site even reveals a 2-5% chance for
severe on Friday. Given increasing confidence for precip and the
clear instability signal, have also added slight chance thunder
for Friday. 00z NBM mean QPF ranges from 0.10-0.25, but think this
will increase over the next few runs if current trends persist.

Barnes

&&

.AVIATION...(For the 12z TAFs through 12z Sunday Morning)
Issued at 548 AM CDT Sat Nov 1 2025

Clouds will be on the increase from west to east across central
Illinois this morning. 1030z/530am satellite imagery shows clouds
spilling across the Mississippi River...with MVFR conditions
noted further upstream along/northwest of a KSTJ to KDBQ line.
HRRR/RAP depicts these low clouds shifting E/SE, but diurnally
rising to low VFR by the time they reach the central Illinois
terminals. Based on satellite timing tools, have introduced a
4000-foot ceiling at KPIA by 14z...then further east to KDEC/KCMI
by 17z. Isolated showers will be possible along/west of I-55 this
afternoon, so included a VCSH at those sites accordingly. Once the
upper low responsible for the clouds pivots southeastward into
the Ohio River Valley, skies will clear later this evening. Have
scattered the ceiling at KPIA by 03z, then eastward to KCMI by
07z. Winds will initially be W/SW at around 5kt early this
morning, then will become W/NW at 5-10kt this afternoon.

Barnes

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$