623
FXUS63 KILX 021115
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
615 AM CDT Thu Oct 2 2025

.KEY MESSAGES...

- Above normal temperatures with highs in the mid 80s to near 90
  degrees will continue through Monday over central/se IL, before
  an approaching cold front brings a return to more seasonable
  readings in the low to mid 70s on Wednesday and Thursday of next
  week.

- An elevated wildfire risk will develop this weekend over central
  IL especially by Sunday afternoon, as south to southwest winds
  increase to breezy levels. NBM has a 15-30% chance of wind gusts
  over 25 mph Sunday afternoon nw of the IL river.

&&

.DISCUSSION...
Issued at 345 AM CDT Thu Oct 2 2025

The 08Z/3 am surface analysis shows expansive 1030-1034 mb
Canadian high pressure over southeast Quebec and ridging sw across
the Great Lakes and into WI and northern IL. A weak surface trof
was just south of the Ohio river into eastern AR. Aloft strong
500 mb high was over northern Mexico and ridging ne over IN with
500 mb heights of 586-587 decameters over IL. IR Satellite
imagery shows scattered to broken Cirrus stratus clouds over over
all but far se and far nw IL and lifting ne. Temps at 330 am were
in the mid 50s to lower 60s. Dewpoints ranged from the low to mid
40s from Lacon to BMI to Paris northeast while more moist
dewpoints in the mid to upper 50s in southeast IL and from Macomb
to Lincoln to Mattoon sw. Winds were light ENE to SE or calm over
central/se IL. Latest CAMS show patchy fog developing in southern
IL next few hours, possibly as far north as highway 50. Any fog
the develops should dissipate by 8 am.

Strong Canadian high pressure to settle southward into the mid
Atlantic States and ridging westward into the mid MS river valley
on Friday and continue to ridge back over IL into this weekend.
The upper level ridge to also stay over IL through this weekend
and be strongest over IL on Friday with 500 mb heights approaching
588 decameters. This to continue the warm and dry wx pattern
across the area through this weekend. Though a weak surface
boundary near the Ohio river could develop isolated showers from
mid afternoon into early evening in southern IL, but should stay
south of Clay, Richland and Lawrence counties. Partly to mostly
cloudy skies from cirrus clouds early this morning should trend
partly mostly sunny this afternoon as these clouds decrease from
the west. Very warm highs in the upper 80s today with mid 80s near
the Indiana border where cirrus clouds hang on longer. South to SE
winds generally under 10 mph today. Lows overnight in the lower
60s, with some upper 50s near the Indiana border around Vermilion
and Edgar counties. Mostly sunny skies and sw winds under 10 mph
on Friday with very warm highs in the upper 80s to around 90F but
shy of record highs in the low to mid 90s.

A strong mid/upper level trof digging and moving eastward into the
Western States late this week, to nudge the subtropical ridge over
the Eastern States, east of IL. A frontal boundary to move se into
the northern plains Friday night and Saturday and move se across
Iowa during Sunday and Sunday night. Increase pressure gradient
over central IL during this weekend especially by Sunday to
increase south to sw winds to breezier levels over the IL river by
Sat afternoon and over much of central IL by Sunday afternoon.
Summerlike daytime temps linger through Monday with highs in the
mid 80s to near 90F this weekend and in the mid 80s Monday.

Models have trended quicker with bringing 20-30% chance of showers
and isolated thunderstorms into central and SE IL late Monday
afternoon and Mon night, with 30-40% chance on Tue as cold front
moves se into the area. Best chances shift into southeast IL
during Tue night with CWA dry on Wed into Thu. Highs Tue in the
lower 80s (upper 70s over IL river valley) cool into the low to
mid 70s Wed/Thu as 1028-1030 mb high pressure settles into the
Midwest and Great Lakes region.

Given the antecedent drought conditions over central and
southeast IL, low fuel moisture and increasing winds...concern is
growing for the potential for field fires over the weekend. While
winds and minimum relative humidity values likely will not meet
Red Flag criteria, burning is highly discouraged both Saturday and
Sunday. The Hot-Dry-Windy Index (HDWI) using the GEFS, shows max
daily values rising above the 75th percentile over the IL river
valley Saturday afternoon, and over much of central IL especially
from from Springfield to Paris north on Sunday afternoon (based on
a 30-year climatology). We will likely be increasing our
messaging for elevated fire danger as this weekend approaches.

The Climate Prediction Center (CPC) 8-14 Day Outlook for Oct
9-15th has a 50-60% chance of above normal temperatures over IL
and a 35-40% chance of above normal precipitation over central/se
IL. The drought may likely persist or even intensify over central
and southeast during the next two weeks. On a plus side, the
growing season looks to continue over the area through at least
Oct 15th with the coolest lows in the 40s from middle of next week
(Wed night) and on.

07

&&

.AVIATION...  (For the 12z TAFs through 12z Friday Morning)
Issued at 615 AM CDT Thu Oct 2 2025

VFR conditions will prevail at all TAF sites for next 24 hours.
Broken cirrus will become scattered during the morning hours and
remain through the period. Light ESE winds will continue this
morning, but become SSE this morning and continue into tonight.

Auten

&&

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

$$