461
FXUS63 KILX 131730
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1230 PM CDT Sun Jul 13 2025

.KEY MESSAGES...

- Marginal risk for severe thunderstorms (5% chance of 60 mph
  gusts) and a slight risk for excessive rainfall in place for
  areas along and south of I-70 this afternoon into evening.

- Daily chances (20-50%) for showers and storms are advertised
  through the upcoming week, though not everyone will see rain.

- Temperatures will be generally seasonable to slightly below
  normal this week. A cold front later in the week could bring a
  period of cooler temperatures by next weekend.

&&

.DISCUSSION...
Issued at 206 AM CDT Sun Jul 13 2025

The stalled out front across southeastern IL will have convection
develop along it today as a shortwave moves over the area. The
storms could be strong to severe, with a focus on the damaging wind
threat. There is modest CAPE and 30-40 knots of shear, supporting
stronger storms. SPC has a marginal risk in place for counties along
and south of I-70. The severe threat window looks to be from 21z to
03z this evening. However, there is a signal for additional showers
and thunderstorms as far north as a Peoria to Bloomington line.
Heavy rain will also be in play again today, starting around noon.
WPC has place I-70 south in a slight (level 2 of 4) risk of
excessive rainfall. PWAT values are around 2-2.2 inches again today.
The forecast soundings are showing a long-skinny CAPE profile as
well, supporting the heavy rain threat. The crops in that region
might enjoy the heavier rainfall. Any flooding concern will be
around urban areas and poor drainage areas.

Temperatures will be seasonable to slightly below normal this week,
mainly ranging from the low 80s to low 90s during the day. Normal
this time of year is upper 80s. Another cold front passage this week
will be what ushers in the slightly below normal temperatures.

There are several chances for showers and thunderstorms this week
with several disturbances pulsing through. We will take each one as
they come, but know that each day brings its own chances for
precipitation.

Copple

&&

.AVIATION...  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1222 PM CDT Sun Jul 13 2025

A slow-moving frontal system will gradually push south of the I-72
terminals this afternoon. Scattered thunderstorms in the vicinity
of this front are already underway and are anticipated to persist
through the afternoon. We have therefore introduced a TEMPO group
for TSRA at all terminals through about 21z-22z. Flight
conditions will largely remain VFR through 00z, though any
instance of TSRA could result in MVFR visibility.

By late tonight, areas of fog could develop across all terminals,
perhaps reducing visibility into the MVFR/IFR range across the
board before conditions improve after 12z-13z Saturday morning.

Otherwise, winds will be variable throughout this afternoon into
the evening hours, especially as nearby thunderstorm outflow work
to abruptly change wind directions. Winds then become nearly calm
overnight.

MJA

&&

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

$$