746
FXUS63 KILX 152303
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
503 PM CST Sat Nov 15 2025

.KEY MESSAGES...

- Temperatures will turn seasonably cool starting tonight with
  lows mainly in the 30s and highs in the 50s the next few days.

- The next chance (70-80%) for precipitation arrives Monday into
  Tuesday. This will do little to aid the ongoing drought
  conditions, with only a 10-30% chance for more than a half inch
  of rainfall.

- A better opportunity for widespread beneficial rainfall arrives
  late Thursday into Friday. There is a 30-50% chance for rain
  amounts greater than 1 inch.

&&

.DISCUSSION...
Issued at 150 PM CST Sat Nov 15 2025

A dry cold front working its way across the area this afternoon will
bring temperatures back to near normal values tonight as colder air
trailing the front moves in, with lows ranging from mid 30s north of
I-72 to lower 40s south of I-70. A fairly substantial pressure
gradient across the area will keep winds blowing overnight,
weakening from 10-15 mph and gusts over 20 mph in the evening to 5-
10 mph by morning, but this will keep temperatures from falling more
substantially through mixing. A mostly sunny day is on track for
Sunday, with the northwest winds slowly diminishing as high pressure
approaches. Highs should reach lower to mid 50s, fairly seasonable.
The high will drift across the area Sunday night, allowing winds to
go light and variable. With a very dry air mass over the area and
dewpoints potentially in the teens, there is potential to see a very
efficient radiational cooling set up, however increasing mid and
high level clouds could disrupt this potential. For now, lows around
30 derived by NBM look reasonable, but there is potential for
temperatures to depart several degrees from this mid-range forecast.
Another seasonable, dry day is on track for Monday, while a weather
system approaches from the west, increasing cloud cover.

The first precipitation in the forecast is Monday night as a surface
low approaches the mid Mississippi Valley, spreading moist warm
advection into central and SE IL, and producing a good signal among
models for light precipitation. Amounts will likely be around a
quarter inch or less over most of the area, but south of I-70 has
potential (30%) to see amounts over a half inch as precipitation
lingers later into Tuesday. Still, it appears unlikely this system
will significantly mitigate current drought conditions as there is
less than a 10% chance of seeing over an inch south of I-70, and
less than a 10% chance of over a half inch in most of central IL.
There should be scattered thunderstorms with this system as mean
MUCAPE values reach around 500 J/kg from I-72 southward. Severe
storm potential looks to be negligible as CAPE profile will be
skinny and elevated according to forecast soundings.

Tuesday afternoon through Wednesday are likely to be dry with
slightly warmer than normal temperatures as it appears shortwave
ridging will dominate the pattern with a frontal boundary likely to
be lingering far enough south of the area to keep conditions dry
this far north.

The next weather system of interest looks on track for late in the
work week. Model consensus has come into good agreement for a potent
low to eject out of the southwest U.S. and begin to phase with a
northern stream shortwave, traversing the mid-mississippi valley
late in the week. Run-to-run consistency is increasing with this
scenario as well. However, considerable differences in timing,
track, and strength remain. Impacts could range up to heavy rain and
severe thunderstorms in central IL given some potential scenarios,
however median precipitation from ensemble guidance remains below an
inch, with less than a 10 percent chance of exceeding 2 inches. CAPE
forecasts are unimpressive in ensemble means, however this could be
driven by GFS tendency to under forecast CAPE at extended duration
and timing differences among models.

Temperatures will continue a bit warmer than normal through late
this week, then return to near normal next weekend as cooler air
arrives behind the late week system.

37

&&

.AVIATION...  (For the 00z TAFs through 00z Sunday Evening)
Issued at 503 PM CST Sat Nov 15 2025

Northwest winds will remain elevated through most of Sunday with
sustained speeds between 10-15 kt. Surface high pressure will
settle in from the northwest Sunday evening, allowing winds to
ease by the end of the TAF forecast. Mostly clear skies are
expected, with just a few passing mid/high clouds at times.

NMA

&&

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

$$