623
FXUS63 KILX 301939
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
239 PM CDT Mon Jun 30 2025

.KEY MESSAGES...

- Look for scattered thunderstorms from late this afternoon into
  this evening, with isolated damaging winds being the main
  concern. Locally heavy rainfall is also possible.

- Somewhat drier air is anticipated from Tuesday through Thursday,
  with minimal precipitation chances. Hot and humid conditions
  return late in the week, with afternoon heat indices of 95 to
  105 degrees each day Friday (July 4th) through Sunday.

&&

.DISCUSSION...
Issued at 239 PM CDT Mon Jun 30 2025

The main concern for this afternoon and evening is scattered
thunderstorms developing ahead of a cold front. A zone of lift is
currently observed on satellite from northeastern MO through
about Peoria to the south side of the Chicago metro area. Minimal
capping is in place per the SPC mesoanalysis, however the sluggish
speed of storm development demonstrates that at least some MLCIN
still exists. Anticipate storm coverage and intensity to gradually
increase through early this evening, becoming scattered along the
boundary. DCAPE increases with eastward extent, and so does the
likelihood for isolated strong to severe wind gusts occurring.
Isolated severe wind gusts are most probable from 5-8 pm near and
east of I-55. In addition, PWAT values from around 1.5 inches
north of I-74 to near 2 inches south of I-70 may promote moderate
to heavy rain rates with the storms that develop.

Once the front makes its way through central Illinois this
evening, look for somewhat drier air from Tuesday through Thursday
along with high temperatures dropping into the mid-upper 80s,
with little chance for precipitation. Late in the week (by
Friday), anticipate heat and humidity to return as a mid-level
ridge axis traverses the Midwest. Heat index values in excess of
100 F are anticipated for at least portions of the area, at least
through Saturday, with perhaps some slight decrease in heat index
values from Sunday into early next week. The pattern at that point
places central Illinois north of a mid-level ridge over the
southern Plains, with any small-scale disturbances moving through
the flow perhaps able to touch off thunderstorms and rain.

AAT

&&

.AVIATION...  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1238 PM CDT Mon Jun 30 2025

The main aviation concern through 18z Tuesday will be scattered
thunderstorms late this afternoon through this evening. Primary
forcing will be a cold front now from southeastern IA into far
northwestern IL, combined with daytime heating. Isolated storms
ahead of the front this afternoon cannot be ruled out, though they
are fairly low probability. In addition to lightning and lowered
visibility from heavy rain, isolated wind gusts in excess of 40 kt
could occur with this evening`s storm activity.

Outside of storms, low VFR to brief MVFR ceilings are a
possibility this afternoon.

AAT

&&

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

$$