405
FXUS63 KILX 181903
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
103 PM CST Tue Nov 18 2025

.KEY MESSAGES...

- There is a level 1 of 5 (marginal) risk for severe thunderstorms
  today south of a roughly Pana to Paris line. The primary hazard
  would be hail up to 1 inch in diameter.

- The next opportunity for rain arrives late Thursday into Friday
  night. The axis of heaviest rain has shifted south, but there is
  still a chance for rain amounts greater than 1 inch south of
  I-70.

&&

.DISCUSSION...
Issued at 103 PM CST Tue Nov 18 2025

The low pressure system is moving eastward today, with a warm front
draped over the southeastern part of the CWA. SPC has maintained a
marginal risk (level 1 of 5) of severe weather for south of a Pana
to Paris line. The dewpoint gradient looks to be along the southern
CWA border. The triple point is expected to move through southern IL
this afternoon, which would increase the chances for severe storms
with hail, wind, or even a tornado, the further south you travel
through the state. South of I-70, the CAMs show 1000-1200 J/kg of
MUCAPE and ~30 knots of effective wind shear. The freezing level is
around 9k-10k ft. Most (if not all) of the storms that develop down
there today will be elevated, supporting the hail threat. However,
if one of these storms can latch onto a boundary or become surface
based, a tornado could spin up.

For an example of how the afternoon redevelopment could go, let`s
take a look at the HRRR. The HRRR shows a corridor of strong (maybe
severe) storms traveling east along the I-64 corridor, just south
of our CWA, from 19z-23z. The NAMnest is more north, with the
storms stretching to the I-70 corridor. Area of concern for our
forecast area would be approximately the I-70 corridor and south.
Currently, the NAMNest looks to be initializing the general area
of the ongoing cells the best.

Wednesday would be a brief break in the rain as there is a lull
between systems. Early Thursday morning, another low pressure system
will pass through central and southeastern IL, bringing increased
Gulf moisture and slightly warmer temperatures in for Thursday.
Above freezing temperatures keep the precipitation type rain,
thankfully. This system could deliver higher rainfall amounts
compared to the ongoing system. From Thursday morning to Saturday
morning, QPF of 1-1.5 inches is in the forecast.

Temperatures stay near or just above normal for the next week. The
warmest day this week is Thursday with highs in the upper 50s to low
60s and lows in the upper 40s to low 50s. Behind the low pressure
system Friday, temperatures will drop back down to near normal.

Copple

&&

.AVIATION...  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1112 AM CST Tue Nov 18 2025

Low pressure will pass just south of the terminals this
afternoon. Lowering ceilings and backing winds are expected with
passage of the low. ESE/SE winds currently in place are expected
to back to the NE/N this afternoon and should remain out of that
direction the remainder of the period. Meanwhile, MVFR/IFR
ceilings are expected to continue to expand across the region,
bottoming out IFR everywhere overnight along with some patchy fog
potential. Thunderstorm chances have shifted further south away
from the terminals, though occasional light rain cannot be ruled
out through the afternoon.

Deubelbeiss

&&

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

$$