141
FXUS63 KILX 142343
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
643 PM CDT Mon Sep 14 2026

.KEY MESSAGES...

- After a brief respite, temperatures will again run well above
  normal the remainder of the week. Per LREF ensembles, probabilities
  of high temperatures above 95 degrees are generally 40-60% in
  areas south of I-70 through the upcoming weekend.

- An incoming cold front will stall over central Illinois, with
  periods of showers and thunderstorms Tuesday and Wednesday.
  There is a low (5-15%) probability of damaging winds with the
  storms Tuesday afternoon and evening.

&&

.DISCUSSION...
Issued at 220 PM CDT Mon Sep 14 2026

Dew point temperatures this afternoon are only in the mid 40s to
lower 50s across the forecast area. However, as southerly winds
increase overnight, a fetch of Gulf moisture will bring them up
into the mid 60s over west central Illinois by daybreak. Ahead
of the incoming cold front, this juicier air mass will
overspread central Illinois on Tuesday. As temperatures over
much of the area reach well into the 90s, triple digit heat
indices will return to areas near and south of I-72. There
remains a concern with needing a heat advisory, but at the
present time, the highest dew points will be closest to the
front, where temperatures should only reach the 80s. With the
front stalling over central Illinois, highs in the 90s will
continue south of it the remainder of the week. ECMWF Extreme
Forecast Index is near the top of the scale through Thursday.
Temperatures may fall just shy of records, but will be close in
some instances (see table in Climate section below).

Mixed layer CAPE`s over the forecast area are progged to reach
2000-2500 J/kg on Tuesday, with decent 0-6km shear around 30-40
knots immediately along the front. Several of the CAM`s are showing
development near the I-72 corridor toward mid to late afternoon,
though just south of the axis of highest shear. SPC Day2
convective outlook hasn`t changed too much, still highlighting a
level 1 risk of severe weather over nearly the entire forecast
area. Periods of shower/storms continue through mid week, though
they will shift northward with time as the front begins to lift
back north.

As we get into the weekend and early next week, persist upper
level high pressure over the lower Mississippi Valley should
finally shift eastward, allowing for some cooler weather to
arrive by Monday. However, the international models are
suggesting ridging redeveloping over the Plains early next week,
edging eastward. with a warming trend. CPC outlook for September
20-24th indicates a 50-60% chance of above normal temperatures
to start autumn.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 629 PM CDT Mon Sep 14 2026

A warm front will gradually lift across the area tonight,
shifting winds from southeast to south. At the same time, a
low- level jet will develop just west of the regional terminals,
resulting in low-level wind shear (LLWS) at KPIA and KBMI.

Scattered showers and thunderstorms remain a low probability
(30%) for Tuesday afternoon as a cold front pushes across the
region. A PROB30 mention for -TSRA has been added (21z-24z) with
this round of TAFs.

Outside any thunderstorm activity, VFR conditions are forecast
to persist through much of this period.

&&

.CLIMATE...
Issued at 220 PM CDT Mon Sep 14 2026

Record temperatures the next several days:

Location         Tue        Wed       Thu       Fri       Sat
========       ========  ========   =======   =======   =======
Bloomington    102/1939   98/1939   97/1927   97/1906   95/1948
Champaign       98/1939   98/1939   94/2018   97/1893   94/1948
Charleston      99/1939   98/1927   98/1927   97/1954   96/1925
Decatur        101/1939   99/1939   97/1954   96/1983   97/1955
Jacksonville   101/1939   97/1939   97/1927   95/1955   96/1925
Olney          104/1939  100/1927   99/1927   99/1953   98/1940
Peoria         100/1939   94/1939   95/1927   93/1908   95/1948
Springfield    100/1939  100/1939   95/1954   95/2018   95/1978

&&

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

&&

$$

KEY MESSAGES...Geelhart
DISCUSSION...Geelhart
AVIATION...MJA
CLIMATE...Geelhart