216
FXUS63 KILX 240836
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
336 AM CDT Tue Jun 24 2025

.KEY MESSAGES...

- Hot and humid weather will prevail this week. High temperatures
  will top out in the lower to middle 90s...with afternoon heat
  index values peaking in the 100-105 degree range through at
  least Thursday.

- Scattered thunderstorms will develop daily through the weekend.
  Despite the numerous rain chances, some locations will remain
  dry as the heaviest and most widespread rainfall stays N/NW of
  central Illinois.

&&

.DISCUSSION...
Issued at 336 AM CDT Tue Jun 24 2025

...Heat Advisory Through Thursday...

Typical summertime heat and humidity will persist this week. High
temperatures will top out in the lower to middle 90s and dewpoints
will hover in the lower to middle 70s...resulting in peak afternoon
heat index values of 100 to 105 degrees. In addition, muggy
overnight lows in the middle 70s will provide limited relief for
those without air conditioning. As a result, the Heat Advisory
will remain in effect through Thursday.


...Daily Thunderstorm Chances...

While the current forecast features rain chances every day, its
important to stress that some locations will see little to no
rainfall through the end of the week...as the heaviest/most
widespread precipitation continues to focus across Iowa into
Wisconsin and far northern Illinois. The latest 7-day QPF
from the Weather Prediction Center (WPC) generally features
around 1 inch of rainfall across central Illinois from today
through next Tuesday...which is right at average for this time of
year.

A frontal boundary will settle southward and stall from southern
Lake Michigan to southern Iowa today. Scattered thunderstorms will
develop along/ahead of the synoptic front as well as any outflow
boundaries left behind by convection currently ongoing across
Iowa/northern Missouri. While CAMs show varying solutions, the
general consensus suggests the greatest areal coverage (40-50%)
of thunderstorms will develop along/north of I-72 late this afternoon
and evening. Meanwhile further south away from the primary
forcing mechanisms, storm coverage will be much less (around 20%).

With the front remaining stationary, scattered thunderstorms will
develop once again on Wednesday...with the highest chances focused
across the northern half of the KILX CWA.

As has been noted by the past few model runs, an area of low
pressure is progged to develop along the tail end of the front on
Wednesday, then lift northeastward into the Upper Midwest by
Thursday. This will temporarily pull the boundary back northward
and result in reduced rain chances for Wednesday night and
Thursday.

Once the low passes, the front will once again get pushed southward
by the end of the week. While the boundary will weaken considerably,
it will still serve as a forcing mechanism within the moisture-rich
environment to trigger scattered thunderstorms Friday/Saturday.

By the end of the forecast period, a short-wave trough dropping
southeastward out of Canada will push a stronger cold front into
and through central Illinois by early next week. At this point, it
appears FROPA will most likely occur on Monday...followed by an
airmass change that will finally bring cooler and drier air into
the region by next Tuesday.

Barnes

&&

.AVIATION...  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1211 AM CDT Tue Jun 24 2025

Showers and storms are ongoing northwest of the terminals within a
trough that stretches from the central Great Plains into the Upper
Midwest. This activity should stay northwest of the terminals
overnight, but outflow from these storms will turn winds more
westerly during the day Tuesday. Scattered showers and storms will
develop over central Illinois Tuesday evening, though confidence
in specific timing and location is low precluding more than a
prob30 mention at this time. Outside of precip, VFR conditions
will prevail through the period.

Deubelbeiss

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT Thursday for ILZ027>031-036>038-
040>057-061>063-066>068-071>073.

&&

$$