686
FXUS63 KILX 051134
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
634 AM CDT Tue May 5 2026

.KEY MESSAGES...

- Waves of showers will continue today, with a few
  thunderstorms along and south of roughly I-70 where there is a
  low (5-14%) risk for flooding.

- Showery and cool weather will continue through the end of the
  work week, with the next chance (40-50%) for storms arriving
  Saturday night into Sunday. The severe weather risk appears
  low at this time.

&&

.DISCUSSION...
Issued at 1241 AM CDT Tue May 5 2026

***** STORMS EARLY THIS MORNING, RAIN TODAY *****

At 1230am, scattered thunderstorms, some approaching severe limits,
were ongoing across portions of central Illinois. Given much of this
activity is behind an outflow boundary sent out of evening storms,
the wind risk should be low, though with some of the taller cores
can`t fully rule out a microburst or two via precipitation loading.
We have received several reports of hail up to 1 inch in diameter
recently, which is not surprising given 500-1500 J/kg MLCAPE and 30-
35 kt effective bulk wind shear apparent in the RAP`s mesoanalysis.
Due to a 40-50 kt LLJ, strongly veering low level winds should
sustain storms for at least a few more hours, with nearly 600
m^2/s^2 0-1km SRH evident on both VWX and IND`s VAD profilers. Most
convective allowing models (CAMs) and Warn on Forecast System (WoFs)
members suggest activity will abate with waning instability after 2-
3am or so, but a weak disturbance riding along the front will spark
additional rain area-wide and perhaps a few thunderstorms in
southeast Illinois near daybreak. Showers are forecast to continue
for most of the area (though mainly near/south of I-72) much of the
day, with the most persistent activity near and south of roughly I-
72/Danville. Given heavy rainfall (1.25"+ in an hour) with the
storms early this morning, and the heavy rain portions of central
and southeast Illinois received last week, the threshold for
flooding will be lower than normal. With HREF/NBM showing a 10-30%
chance for more than 2 inches of rainfall in southeast Illinois,
we`ll need to keep one eye on this area for flooding, though we
suspect the chance is low given at least half of that 2 inches
should be spread out over 12+ hours mid morning through late
evening. With cloud cover, showers, and low level northerly flow
behind the cold front, it`ll be a cool and gloomy day with highs in
the mid to upper 50s south of roughly I-72/Danville where the rain
will be most persistent. Further north, temperatures may top out in
the low-mid 60s with any breaks of sunshine, especially north of a
Macomb to Bloomington line.

***** STAYING COOL WITH LOW PRECIP CHANCES LATE WEEK *****

Another shortwave will bring a 20-30% chance for light rain tomorrow
morning into early afternoon, though rain amounts will be much
lighter with NBM giving only a 10-25% chance for a wetting rain
(0.10" or more). With a cool airmass aloft (850mb temperatures
near/below 0 degC), high temperatures will likely (50-70% chance)
fall shy of 60 degF area-wide tomorrow afternoon. This trend for
cool and showery weather will continue into the first part of the
weekend as the parent upper level trough lingers over Ontario/Quebec
to foster continued northwest flow across the Midwest. The
deterministic GFS and ECMWF suggest we may get a weak push of warm
advection ahead of a shortwave trough to warm the area into the 70s
Saturday and provide some instability for showers/storms Saturday
night into early Sunday (40-60% chance). Otherwise, conditions
look mostly dry next week, with a warming trend apparent in
global and ensemble data; by Wednesday, there is a 40-60% chance
for high temperatures warmer than 80 degrees from NBM.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 635 AM CDT Tue May 5 2026

All sites will start as VFR with mid clouds and light showers.
BMI, SPI, DEC, and CMI will see continuous showers through the
day and into tonight, but cigs will decrease later this
afternoon and again tonight. DEC and CMI will see MVFR cigs
afternoon and evening since the front will be closer to them.
SPI might, but only dropping them to 3.5kft. BMI will remain VFR
and PIA should see an end to the precip in the afternoon. Winds
will be north to northwesterly but then become more north-
northeasterly during the day and then northeast for the evening.
Speeds will be around 10kts through the period as the front will
be slow to sink south.

&&

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

&&

$$

KEY MESSAGES...Bumgardner
DISCUSSION...07/Bumgardner
AVIATION...Auten