169
FXUS63 KILX 310538
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1238 AM CDT Mon Aug 31 2026

.KEY MESSAGES...

- Hot and mostly dry weather is forecast this week with
  afternoon heat indices peaking above 100 degrees in west-
  central Illinois on Monday and areawide beginning Tuesday.

&&

.DISCUSSION...
Issued at 120 PM CDT Sun Aug 30 2026

Radar mosaic has shown a persistent band of showers and isolated
storms impacting areas north of a Macomb to Pontiac line most of the
morning into early this afternoon. This activity has been fed by a
30-40 kt low-level positioned from central Kansas into northern
Illinois and should come to an end here soon as the low-level
jet continues to wane. Temperatures were reduced near/north of
the I-74 corridor for today due to lingering precipitation and
cloud cover, but areas south of there are already observing
values in the upper 80s to low 90s as of 1 pm.

A ridge of high pressure centered over the Southern Plains will
spread east this week, bringing a stretch of hot and mostly dry
conditions. Temperatures this week will peak in the 90s with
the hottest days expected by midweek. Dewpoints in the upper 60s
to low 70s will send heat indices over 100 degrees as early as
Monday in west-central Illinois and then areawide Tuesday,
continuing through at least Thursday. High temperatures look to
remain just shy of records at our official climate sites, but
overnight lows in the mid 70s will likely tie or break our
warmest low records.

A compact northern stream trough will track through the southern
Canadian Prairies/Northern Plains this week, sparking
occasional chances for showers and storms north of our area. The
upper ridge will flatten out some late in the week as the
trough tracks north of the Great Lakes Region, allowing
shortwave energy to intrude further south. The NBM shows low
chances for precipitation Thursday night through the start of
the weekend before the ridge reamplifies later this weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1235 AM CDT Mon Aug 31 2026

VFR conditions will prevail at all TAF sites next 24hrs.
Scattered mid clouds around 15kft will cover all sites overnight
but then gradually dissipate for tomorrow, leaving just
scattered cirrus through the day. By evening, clear skies are
expected in the south with scattered high clouds continuing at
PIA and BMI. Winds will be south to southwest through the period
with speeds less than 10kts now and again this evening. Daytime
winds will be 10-15kts.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM this afternoon to 7 PM CDT this
evening for ILZ027-036-040-041-047>052.

&&

$$

KEY MESSAGES...NMA
DISCUSSION...NMA
AVIATION...Auten