479
FXUS63 KILX 040513
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
Issued by National Weather Service St Louis MO
1213 AM CDT Wed Jun 4 2025

.KEY MESSAGES...

- Periods of scattered thunderstorms this evening through Friday
  may generate localized heavy rain. The risk of flooding is low
  (5%), but nuisance ponding of water in poor drainage areas may
  occur.

- There is a level 2 of 5 (slight) risk for severe weather west
  of the IL River this evening. The primary risk will be localized
  damaging thunderstorm winds.

- Temperatures behind the cold front will be slightly cooler
  through the new week. Highs in the upper 70s near 80, and lows
  in the upper 50s to mid 60s.

&&

.DISCUSSION...
Issued at 208 PM CDT Tue Jun 3 2025

Here comes the rain. Scattered showers and thunderstorms have
been percolating across west central IL so far today. The line of
thunderstorms that will bring the risk of damaging winds and
*maybe* an isolated tornado enters the western part of the state
between 23z and 01z. The SPC has west of the Illinois River in a
slight risk for this evening into overnight hours. It looks like
the severe risk will be when it first enters Illinois, but will
lose steam as it makes its way east. We may have a 2-3 hour period
where we could see the damaging winds. Instability initially is
1500-2500 J/kg of MUCAPE but as it progresses, the instability
rapidly decays. The shear is being modelled stronger than in
previous days. We have been seeing bulk shear of 20-30 knots and
now today, the CAMs are depicting 40-50 knots of bulk 0-6km shear
just ahead of the front. There is an inverted v signature on model
soundings. This could indicate potential microburst activity. The
long, skinny CAPE profile on the model soundings, and the PWAT
values of 1.7-2 inches indicate more of a heavy rain risk. These
PWAT values look to linger over the area through at least
Thursday. We will see beneficial and much needed rain, but
localized, urban flooding is possible. At this time, the risk
looks to be highest near and south of the I-72 corridor. The crops
will be greatly appreciative of the multiple rounds of rain this
week. From tonight to Thursday morning we could see rainfall
amounts of 1-2.5 inches

Tomorrow we have a marginal risk for severe weather east of I-55,
primarily for the damaging wind risk. However, most of us will
experience much needed rain. The slowly departing cold front
hanging across central IL, along with multiple shortwaves
seemingly pulsing through the region through Friday, bring several
rounds of showers and thunderstorms for the rest of the week. We
should see a dry Saturday, but additional rain chances return on
Sunday for the new week.

Tomorrow IL EPA is increasing our air quality concerns with it
becoming unhealthy for sensitive groups (orange category) north of
a Quincy to Paxton line. The Canadian wildfire smoke will make an
attempt to return south behind the cold front.

Temperatures cool slightly behind the front today. Highs through
the weekend into the new week will be in the upper 70s to near 80.
Lows will be in the upper 50s to mid 60s.

Copple

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1210 AM CDT Wed Jun 4 2025

Widespread rain and some embedded thunderstorms will continue to
slowly push eastward overnight into Wednesday morning. Brief
reductions in visibilities to 4-5SM are expected. Ceilings will
also lower from west to east, with IFR conditions most likely at
PIA. For the remaining terminals further east, low MVFR
ceilings are more likely.

&&

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

&&

$$

DISCUSSION...WFO LSX
AVIATION...WFO LSX