267
FXUS63 KILX 152316
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
616 PM CDT Wed Jul 15 2026

.KEY MESSAGES...

- Seasonably warm and humid weather continues through at least
  Saturday with maximum afternoon heat indices around 100
  degrees, give or take a few degrees.

- Shower and storm chances return late week with the best
  chances expected on Friday.

&&

.DISCUSSION...
Issued at 133 PM CDT Wed Jul 15 2026

High pressure centered over the central US remains anchored in place
atop of an upper low in the southern US (rex block), keeping
temperatures seasonably warm. Dewpoints in the low to middle 70s
have led to peak afternoon heat indices in the middle 90s to near
100 so far today, with similar conditions expected through at least
Saturday. However, the return of scattered convection beginning
tomorrow could alleviate the heat for some.

The upper ridge will begin to break down Thursday into Friday as
several shortwave troughs work through the eastern Canadian
provinces, just north of the Great Lakes Region. Bits of energy from
the previously mentioned upper low will ooze northward in a weakened
state as soon as tomorrow, bringing enough forcing to support
scattered storms through Saturday (Friday having the best chances).
Moderately strong instability could support a few stronger storms
capable of gusty winds. However, weak vertical wind shear should
limit storm longevity and organization. High PWATS and slow storm
motions will favor torrential downpours, with the 15.12Z HREF LPMM
showing localized pockets of over 2" possible.

Shower and storm chances exist Sunday into the early parts of next
week as a few shortwave troughs dive through the Great Lakes Region,
sending a couple of cold fronts through the area. The first cold
front will arrive on Sunday, stalling out just south of the area
before lifting back northward on Monday ahead of the next
approaching wave. Although a subtle reprieve from the heat will come
for some Sunday into Monday, a more noticeable cool down won`t
arrive until Tuesday or Wednesday after a stronger upper wave sends
a more progressive cold front through the area.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 616 PM CDT Wed Jul 15 2026

Diurnal cumulus will begin to fade with sunset, but pick up
again toward mid to late Thursday morning. Some concern remains
with shallow ground fog toward daybreak. Exact placement is
still uncertain, though KSPI tends to be more prone to this
occurrence, so will only include a mention there at this point.
Late in the period, scattered thunderstorms will begin to
develop across the south half of the state, and will include a
PROB30 mention at KDEC/KSPI.

&&

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

&&

$$

KEY MESSAGES...NMA
DISCUSSION...NMA
AVIATION...Geelhart