806
FXUS63 KILX 080656
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
156 AM CDT Tue Sep 8 2026

.KEY MESSAGES...

- Summer heat and humidity return today and Wednesday. There is
  a 50-80% chance of heat indices greater than 95 degrees south
  of I-70 tomorrow afternoon.

- Rain and thunderstorms move in tomorrow into Thursday morning,
  bringing a damaging wind risk and heavy rainfall. QPF shows
  1-3 inches of rainfall south of I-72, with the greatest
  amounts near and south of I-70.

&&

.DISCUSSION...
Issued at 156 AM CDT Tue Sep 8 2026

Temperatures will warm back up into the 90s today and Wednesday as
the upper ridging builds back eastward with 850 mb temperatures of
20-24C. Tomorrow, moisture transport will increase ahead of the cold
front bringing soupy dewpoints in the 70s into the central part of
the state. There is a 50-80% chance of heat indices greater than 95
degrees south of I-70 Wednesday afternoon, from the HREF. There
could be some limitations with how hot it could get on Wednesday
with the cloud cover from convective debris across the state and how
fast the front may move through. For areas north of the IL River
Valley, today could be the hottest day out of the two.

The cold front will move through tomorrow into tomorrow night as the
ridge gets broken down by the upper low moving over Canada. It will
clear out the sweltering mid to upper 90 temperatures, leaving highs
in the low to mid 80s before building back to upper 80s to near 90
for the weekend. The LREF suggests that there is a 50-70% chance of
high temperatures cooler than 80 degrees by next Tuesday. Could
Autumn be near?

This front will also bring the next chance for substantial rain and
strong-to-severe thunderstorms tomorrow into Thursday. The CAMs are
showing a line of showers & convection along the front entering the
northwest around 10z Wednesday. The initial area of convection may
widely dry out during the day, leaving some scattered activity as
the front pushed southeast through the state. This scattered
activity could have strong to damaging winds and/or hail with them.
Looks like by 00z Thursday, redevelopment will occur in the
southeast in the evening as the LLJ kicks in, potentially training
near and south of I-70. This redevelopment could continue into
Thursday morning and may prove to be a flash flooding risk, rather
than severe. However, this area can likely take quite a bit of rain
before flooding becomes a major concern. The 6 hour FFG for the
southeast is 3-5 inches. QPF shows 1-3 inches of rainfall south of I-
72, with the greatest amounts near and south of I-70, from 06z
Wednesday to 00z Friday. PWATs in that area are forecast to be 2.0-
2.5 inches.

WPC has maintained a D2 marginal risk ERO south of I-72, with a
slight risk area just off to the east, including southwestern IL.
SPC has expanded the D2 marginal risk for severe weather north to a
southern Knox County to Livingston County line and south. Damaging
winds and hail are the most likely hazards with the area of storms.

Additional low-end chances exist for showers and thunderstorms
through the weekend. Due to low predictability and model spread,
broad-brushed 20-40% PoPs remain in place from Friday night through
early next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1211 AM CDT Tue Sep 8 2026

VFR conditions continue through Tuesday evening, with mainly
scattered high based clouds. Easterly winds will trend more
toward the south through Wednesday morning, though remaining
below 10 knots.

&&

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

&&

$$

KEY MESSAGES...Copple
DISCUSSION...Copple
AVIATION...Geelhart