406
FXUS63 KILX 081900
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
200 PM CDT Wed Oct 8 2025

.KEY MESSAGES...

- Low temperatures will dip into the 30s across parts of central
  and southeast Illinois both tonight and Thursday night.

- The highest probability (40-60% chance) for readings below 38F
  and perhaps patchy frost will be focused along/east of I-57
  Thursday night.

&&

.SHORT TERM...(Tonight through Thursday)
Issued at 200 PM CDT Wed Oct 8 2025

High pressure anchored over the Great Lakes will dominate the
weather across central Illinois over the next 24 hours. A cool/dry
airmass is currently in place as evidenced by 18z/1pm surface
dewpoints in the upper 30s and lower 40s. Given the dry environment,
temps will efficiently cool after sunset...quickly dropping from
afternoon highs in the upper 60s to around 70 degrees into the
middle 50s by 8pm. The center of the high will remain over
Wisconsin, so think a light NE breeze of 5-8mph will persist
through the night. Modest mixing of the boundary layer will
therefore offset optimal radiational cooling and should keep
overnight lows from completely bottoming out. Have still undercut
numeric guidance by several degrees, with lows dropping into the
upper 30s and lower 40s. Abundant sunshine will prevail on
Thursday, which will boost afternoon readings into the upper 60s
and lower 70s. As the ridge axis shifts slowly eastward, boundary
layer winds will begin to veer to a more southerly direction
Thursday night...especially along/west of I-55. Meanwhile further
east, it appears winds will be lighter and may go nearly calm. As
a result, think the coldest readings and best chance at seeing
some patchy frost will materialize along/east of I-57...where the
12z NBM shows a 40-60% chance of temps dipping below 38 degrees.

Barnes

.LONG TERM...(Friday through Next Wednesday)
Issued at 200 PM CDT Wed Oct 8 2025

12z Oct 8 models continue to agree that a weak cold front will
push into area on Friday as the prevailing ridge axis shifts to
the East Coast. The boundary will have very little moisture to
work with, so am expecting little more than an increase in cloud
cover and a shift in the wind with FROPA. Once the weak front
passes, a return to mild and dry weather is anticipated this
weekend. Highs will generally reach the lower to middle 70s each
day.

After that, upper ridging will build over the Midwest and the
boundary will get shunted back northward by early next week. Some
models are suggesting a few showers may develop on Monday/Tuesday:
however, the NBM remains dry at this point. The main weather story
will be the warming temps...as temps get back into the lower and
perhaps middle 80s by next Wednesday.

Barnes

&&

.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1202 PM CDT Wed Oct 8 2025

High pressure over the Upper Midwest will drift east into the
Great Lakes. Across central Illinois, northeast winds in place
today will gradually veer to a southeast direction Thursday, but
should remain below 10 kt through the period. VFR conditions are
expected through the period.

Deubelbeiss

&&

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

$$