096
FXUS63 KILX 260702
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
202 AM CDT Wed Aug 26 2026

.KEY MESSAGES...

- Thunderstorms are expected to develop over central Illinois
  later this afternoon and evening. Damaging winds and large
  hail are the main threats.

- Comfortable and dry weather is anticipated Thursday through
  Saturday, followed by the return of summer-like heat early
  next week.

&&

.DISCUSSION...
Issued at 202 AM CDT Wed Aug 26 2026

Water vapor imagery shows a strong ridge of high pressure anchored
over the southwest US with a mid-level trough centered to the
north of Lake Superior. At the surface, a cold front associated
with the aforementioned trough stretches from northern
Wisconsin southward into central Iowa, with convection ongoing
ahead of the boundary in western Wisconsin as of 2 am. A little
closer to home, warm air advection out ahead of the front has
led to widespread mid-level stratus, which is holding
temperatures higher by several degrees compared to this time 24
hours ago. Some CAMs suggest spotty, light showers may develop
within this region through this morning (15% chance), but most
should stay dry.

The mid-level shortwave will track through the Northern Great Lakes
Region today, sending a cold front through Illinois this afternoon
and evening. Out ahead of the front, temperatures are forecast to
warm into the 80s paired with low 70s dewpoints, resulting in
moderate destabilization by this afternoon. SBCAPE values look
to peak around 2500 J/kg combined with bulk shear around 30 kts,
which would be enough to support a few organized storms. CAMs
show scattered storms developing near or east of I-55 by late
this afternoon, then spreading east through the evening. The
primary hazards with any storms that do become organized will be
damaging wind gusts and isolated large hail. The threat for
flash flooding appears low, though pockets of heavy rain will be
possible under any of the stronger storms.

Northwest flow aloft remains in place through late week with a broad
area of surface high pressure controlling the weather pattern
through at least Saturday. This will keep things dry and
comfortable with seasonal temperatures in the low to middle
80s. Upper ridging will begin shifting east into the Midwest
states this weekend, bringing the return of summer-like heat as
surface flow becomes southerly. Temperatures will climb into the
upper 80s to low 90s beginning Sunday, with more tropical-like
dewpoints sending heat indices into the middle to upper 90s
by Monday. A couple upper shortwaves riding the northern
periphery of the ridge could bring showers and storms back into
the area Monday and Tuesday, though most of this should remain
confined over the northern half of the state.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1211 AM CDT Wed Aug 26 2026

A cold front will push across central Illinois Wednesday
afternoon and evening. Overnight through Wednesday morning, S/SE
winds currently in place will very gradually veer to SW/W ahead
of the front, then winds veer to northwesterly behind the
front. Scattered thunderstorms are expected to develop along the
front late afternoon into the evening directly over portions of
central and east central Illinois. Latest suite of guidance
gives about a 30 percent chance for storms along the I-72
corridor (SPI/DEC/CMI) but slightly favor storms forming just
southeast of the terminals and missing them. For now will
maintain a prob30 in the TAFs for those three southern most
sites.

&&

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

&&

$$

KEY MESSAGES...NMA
DISCUSSION...NMA
AVIATION...Deubelbeiss