261
FXUS63 KILX 271815
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
115 PM CDT Wed Aug 27 2025

.KEY MESSAGES...

- Temperatures are anticipated to remain seasonably cool over the
  next seven days, averaging around 3 degrees below what is
  considered normal temperature for late August to early
  September.

- A relatively dry forecast will result in weekly precipitation
  that is well below the normal average of 1 inch.

&&

.DISCUSSION...
Issued at 106 PM CDT Wed Aug 27 2025

Dry, mild and otherwise low-impact weather will persist through
the remainder of the week with North America mired in a blocking
pattern. Call it an omega block. Call it a split flow regime. Call
it whatever you like, but with deep troughing anchored over the
eastern half of the CONUS and an amplified ridge over the West
Coast, there will be very few opportunities for appreciable Gulf
or Pacific moisture to creep back into central Illinois.

With that said, we are monitoring a few short-term disturbances.
This afternoon, an upper-level speed maximum (80-90 kts) and a
subtle mid-level shortwave trough moving through the mid-
Mississippi Valley will lead to increased cloud cover. However,
dry low-level air and high cloud bases should limit any precip to
only a sprinkle. Then, on Thursday, we will see a more defined
shortwave trough track across Hudson Bay, bringing a backdoor cold
front to our region around midday. Due to limited low-level
moisture return ahead of the front, it is expected to primarily
cause an increase in mid-level clouds, with only a slight
possibility (15% chance) of a sprinkle near and north of I-74.

From Tuesday through Friday, a notable pattern change emerges
across the Great Lakes region. Two strong shortwave troughs and
their associated cold fronts will bring fluctuating temperatures;
an improved CAPE/Shear parameter space; and increased chances for
showers and thunderstorms during the latter half of next week.

MJA

&&

.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 114 PM CDT Wed Aug 27 2025

High pressure will remain over the Ohio Valley through the period
resulting in light south to southwest winds across central
Illinois through the period. VFR conditions are expected to
prevail. A weak cold front will approach central Illinois
Thursday. Precip is unlikely (only 15% along the I-74 corridor)
but expect an increase in mid level clouds.

Deubelbeiss

&&

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

$$