153
FXUS63 KILX 070501
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1201 AM CDT Wed May 7 2025

.KEY MESSAGES...

- Low-impact weather will extend through early next week, with
  little or no rain currently in the forecast.

&&

.DISCUSSION...
Issued at 126 PM CDT Tue May 6 2025

Afternoon water vapor imagery depicts an upper-level low pivoting
across the Texas Panhandle with a broadening cloud shield pushing
into the Ozarks. These high clouds will eventually overspread
central Illinois by tonight as the upper low lifts into the Southern
Plains. Mostly cloudy skies will then continue into Wednesday as the
low stalls over SW Missouri.  Temperatures today will surge into the
lowers 70s beneath mostly sunny skies, then into the mid-to-upper
70s by Wednesday (despite the filtered sunshine) as a ribbon of
warmer 850-mb temps sags into central IL ahead of a backdoor
front.

A few of the 12z CAMs (namely the NSSL WRF and FV3) break out an
area of scattered showers Wednesday afternoon from roughly the
Quad Cities to Bloomington-Normal where the more favorable T/Td-
spread pools ahead of the front. These models are probably a
little overzealous, and most cumulus growth tomorrow afternoon
should be limited by dry air entrainment. We have maintained the
15% PoPs along the I-74 corridor for Wednesday afternoon but have
otherwise faded the rain signal.

By Wednesday evening, a digging shortwave trough will move into the
Great Lakes region and help push the backdoor cold front further
into central IL.  The effect this front has on temperatures
Wednesday night will be significant, with short-term guidance
supporting overnight lows in the upper 40s near and north of
I-74; about a 30 degree (F) diurnal swing as winds shift N/NE.

The front will become stalled by Thursday as it bisects central IL
from west-to-east.  Cool and dry conditions are anticipated north of
the front with daily highs in the mid 60s, while areas near and
south of the front get near 70 degF with an isolated shower not out
of the question (< 30% chance).  Very dry air settling in behind the
front will then allow for temperatures to crater Thursday night,
with low-to-mid 40s forecast across a good chunk of the the region.

Ideal spring weather will then be in place this weekend as a
blocking pattern develops over the region.  This stretch of weather
will be characterized by dry conditions, seasonable warmth, low
humidity, and light winds. Our next best chance for rain beyond
this weekend could come as early as Monday afternoon as the
blocking pattern breaks down and begins to get swept back into the
main belt of westerlies. While storms look unlikely early next
week, there could be just enough moisture and lift on the backside
of the departing disturbance to support scattered light showers.

MJA

&&

.AVIATION...  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1201 AM CDT Wed May 7 2025

VFR conditions are expected through the upcoming 24 hours, however
an approaching low pressure system from the southwest and a cold
front approaching from the north will bring increasing clouds to
the central IL terminals and developing east winds switching to
northeast Wednesday evening. Light and variable winds can be
expected overnight, becoming E 6-10 kts by 17Z, and NE 6-12 kts by
01Z-04Z.

37

&&

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

$$