481
FXUS63 KILX 130002
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
702 PM CDT Mon Oct 12 2026

.KEY MESSAGES...

- Record-breaking heat continues through Tuesday afternoon, with
  high temperatures reaching the upper 80s to lower 90s.

- A Marginal Risk (level 1 of 5) for severe thunderstorms exists
  Tuesday night. Some storms will be capable of producing
  localized damaging wind gusts and hail.

- Unsettled weather Tuesday night through Thursday brings
  periods of wet weather, with a 60 to 80 percent chance of 1
  to 2 inches of event total rainfall.

- A sharp cold front transitions the region to much cooler
  conditions late week into the weekend, bringing a potential
  for early morning frost both Saturday and Sunday.

&&

.DISCUSSION...
Issued at 1222 PM CDT Mon Oct 12 2026

Strong low-level warm air advection remains established across
the Midwest under a building upper-level ridge. Mid-level height
rises and persistent south-southwesterly surface winds gusting
up to 25 mph will push high temperatures into the upper 80s and
lower 90s this afternoon, likely breaking daily high
temperature records. Unseasonably warm conditions persist
through Tuesday ahead of an approaching upper-level trough.
Highs on Tuesday again top out in the upper 80s to lower 90s,
roughly 20 degrees above seasonal norms. Record highs remain
susceptible to being broken across central and southeast
Illinois. High resolution guidance shows the front working into
the central CWA through Tuesday afternoon, and CAMs depict a few
post-frontal showers/sprinkles over the northwest CWA. To
account for this, added some 20 PoPs for the Galesburg and
Peoria areas.

Convective initiation occurs Tuesday evening into Tuesday night
as a lead shortwave tracks northeast toward the region. HREF
guidance shows MUCAPE values building to 1000-1500 J/kg paired
with 0-6km bulk shear of 30-40 knots. ML/AI severe guidance,
along with the SPC Day 2 Outlook, maintain a Marginal Risk
(level 1 of 5) for central and western portions of the forecast
area. Primary convective hazards feature isolated severe wind
gusts up to 60 mph and large hail up to quarter size.

The frontal boundary stalls in the area Wednesday into Thursday,
becoming oriented parallel to upper-level southwest flow as
more shortwave energy ejects from the trough to our west. Deep-
layer moisture surges along the boundary, with precipitable
water (PWAT) values reaching 1.75-2.00 inches, exceeding the
95th percentile for mid-October. High-resolution ensemble
forecasts (HREF) and medium-range guidance (ECMWF, GEFS, and
ECMWF-AI) support a few rounds of rain and embedded
thunderstorms, with sizable breaks, Wednesday and Thursday. WPC
excessive rainfall outlooks highlight a Marginal Risk for heavy
rain across central and southeast Illinois both days. Ensemble
guidance (LREF) yields high confidence (60-80% chance) for event
total rainfall exceeding 1 inch, with localized totals up to 2
inches. Some spread is noted in the footprint of heavier
rainfall during this period, with recent guidance trending the
higher values to the northwest sections of the CWA.

A sharp airmass change arrives Friday as an expansive Canadian
surface high pressure system builds into the Plains and Midwest.
The GFS/GEFS continues to be a cold outlier among the guidance
suite, showing temperatures several degrees colder than  the
preferred NBM. Nonetheless, strong cold air advection on Friday
will keep highs below normal in the lower 60s, along with gusty
northwest winds. The first frost of the season will be in play
this weekend, though this will likely hinge on the exact
position of the ridge axis. Confidence in the ridge axis being
overhead during the early morning hours for calm winds and
widespread frost formation is low, but with the cold airmass in
place, lows in the 30s are likely both Saturday and Sunday
morning.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 702 PM CDT Mon Oct 12 2026

VFR conditions will prevail at all TAF sites next 24hrs with
SKC to SCT high clouds through Tue morning. Southwest winds
will be light, under 10 kts through the night. A 40-45 kt low
level jet will develop this evening and cause LLWS through much
of tonight before diminishing in the pre-dawn hours. Winds will
remain southwesterly tomorrow with speeds around 10kts.

&&

.CLIMATE...
Issued at 612 AM CDT Mon Oct 12 2026

Record high temperatures for today and Tuesday:

Location        Monday       Tuesday
========        =======      =======
Bloomington     88/1930      91/1899
Champaign       87/1962      86/1989
Charleston      89/1962      87/2017
Decatur         92/1962      90/1899
Jacksonville    88/1901      91/1899
Olney           89/1928      93/1928
Peoria          87/2024      88/1899
Springfield     89/1962      88/1975


Records for latest 90 degree high temperature for the year:

Location        Date
========        ================
Bloomington     October 15, 1899
Champaign       October 14, 1899
Charleston      October 15, 1897
Decatur         October 15, 1938
Jacksonville    October 30, 1950
Olney           October 22, 1953
Peoria          October 15, 1897
Springfield     October 11, 1962

&&

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

&&

$$

KEY MESSAGES...25
DISCUSSION...25
AVIATION...Auten
CLIMATE...Geelhart