079
FXUS63 KILX 301709
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1209 PM CDT Fri Oct 30 2026

.KEY MESSAGES...

- Scattered showers and a few thunderstorms could bring
  localized rainfall up to 0.5 inches today, primarily west of
  Interstate 55 before shifting north tonight.

- Temperatures near 70 degrees on Saturday will cap off one of
  the warmest Octobers on record.

- A stronger storm system brings widespread rain and breezy
  conditions Monday afternoon through Wednesday morning. There
  is a 50-60% chance for rainfall totals to exceed 1 inch during
  this timeframe, especially along and west of Interstate 55.

&&

.DISCUSSION...
Issued at 325 AM CDT Fri Oct 30 2026

A weak baroclinic zone extends from near Des Moines, Iowa, to
Cincinnati, Ohio, early this morning. Scattered showers and
thunderstorms are ongoing along this boundary, concentrated
primarily near the nose of a 20-30 kt low-level jet. To the
north, downwind of the mid-level trough axis, a surface high
pressure ridge stretches across the Northern Plains, Great
Lakes, and Ohio Valley. Persistent low-level dry air over the
Great Lakes and easterly winds across central Illinois today
create uncertainty regarding how far east precipitation will
push. The highest probability for rain (60%) remains west of
Interstate 55 during the day, with chances shifting northward by
this evening. Forecast rainfall totals through this evening are
generally less than 0.25 inches along and west of I-55, though
localized amounts up to 0.5 inches are possible across far west-
central Illinois where low-level jet forcing is stronger this
morning. Precipitation chances (30-50%) remain focused near and
north of the I-74 corridor tonight through Saturday morning.
Low-level jet forcing will serve as the primary catalyst for any
shower activity that develops.

Precipitation chances taper off by Saturday afternoon and
evening (10-30%) as low-level dry air filters into the area from
the southeast. Despite abundant clouds, temperatures should
once again warm to around 70 degrees areawide, capping what will
be one of the warmest Octobers on record.

Rainfall chances return by Sunday morning as a shortwave trough
advances out of the Southern Plains into the Mid-Mississippi
Valley. Warm-air advection accompanying this system brings a
medium (40-60%) probability of rain, primarily near and south of
the Interstate 72 corridor. However, recent QPF guidance
indicates rainfall totals will remain under 0.25 inches,
offering minimal relief to ongoing dry conditions.

The highest confidence for rainfall over the coming 7 days
spans Monday afternoon through Wednesday morning. During this
period, global models indicate the jet stream will buckle over
the central U.S., driving several mid-level shortwave troughs
southward across the region. While exact phasing details among
these troughs remain uncertain, deterministic and ensemble
guidance strongly agree on a large-scale storm system delivering
periods of widespread rain, breezy conditions, and cooler
temperatures. Additionally, recent NBM guidance indicates a
50-60% chance of rainfall exceeding 1 inch over the 48-hour
period ending at 6 AM Wednesday, particularly for locations
along and west of Interstate 55.

Following the departure of the storm system, a continental
polar (cP) air mass will settle across the area, favoring dry
and mild weather through the latter portion of next week. Expect
cooler conditions, with daily high temperatures around 60
degrees and overnight lows falling into the upper 30s to lower
40s.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1208 PM CDT Fri Oct 30 2026

A stationary front is expected to remain just south of the
terminals with a modest easterly breeze and isolated to
scattered showers across central Illinois. VFR conditions should
prevail through the period, but cannot rule out brief MVFR
ceilings or vsby in or around showers. The thunder threat is
low, but non-zero. As we head into the evening and overnight
hours, the focus for precip is expected to shift slightly
northward favoring PIA/BMI.

&&

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

&&

$$

KEY MESSAGES...MJA
DISCUSSION...MJA
AVIATION...Deubelbeiss