112
FXUS63 KILX 081941
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
241 PM CDT Mon Jun 8 2026

.KEY MESSAGES...

- A heavy rain threat will persist through this evening,
  continuing into the overnight hours south of I-72/Danville.
  Rates of two inches per hour or greater may lead to localized
  flash flooding.

- The combination of heat and humidity will lead to heat index
  values peaking between 95 and 105 degrees on Tuesday and
  Wednesday. Those sensitive to heat should take extra
  precautions.

- The threat for severe weather will increase through this
  week, peaking in the late Wednesday night-Thursday time frame.


&&

.DISCUSSION...
Issued at 241 PM CDT Mon Jun 8 2026

Near record precipitable water values of just over 2" along with
an approaching upper low are driving a heavy rain threat today,
with multiple reports of 2"/hour rain rates. East central IL
will see the greatest threat for heavy rain over the next few
hours. An MCV moving out of southeast MO may lead to
thunderstorm development in portions of southeastern IL that
have yet to see much activity. Some will see a brief break this
afternoon, but with more showers/storms capable of heavy
rainfall moving in from the west we anticipate the flood threat
to persist through at least this evening. A few CAMs depict a
convective complex with an associated MCV moving across MO and
weakening during the overnight hours. The southern portion of
the flood watch has been extended to 7 am to account for this
possibility, as well as to account for the persistent near
record PW values.

The combination of heat and humidity then become a concern for
Tuesday and Wednesday. Heat index values in the mid 90s up to
a few degrees over 100 are anticipated. Particularly following
the extended period of dry and cool conditions experienced
toward the end of May/in the first week of June, this period of
heat and humidity could have more impact than usual. On Tuesday,
a weak moisture boundary may trigger isolated thunderstorms but
little relief from the heat will probably result. Instability is
quite strong, but with shear limited the severe threat should be
limited as well. The main concern would be isolated strong to
severe wind gusts.

The severe weather threat is forecast to increase later in the
week for central and southeast Illinois. Late Wednesday night
into Thursday morning, severe storms coming out of the upper
Mississippi Valley are forecast to weaken as they move toward
central Illinois. The greater threat is anticipated on Thursday
afternoon/evening, with SPC delineating a 30% contour
approximately near and west of I-55.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1246 PM CDT Mon Jun 8 2026

Primary band of heavy rain and thunderstorms is now working its
way through KBMI-KMTO, and should reach KCMI within the hour.
Threats are lightning, rain rates in excess of 1" per hour with
IFR or lower visibilities, and some gusty south winds. Another
round of scattered thunderstorms now in western Illinois is
anticipated to affect the TAF sites during the mid to late
afternoon hours. MVFR to perhaps IFR ceilings are forecast to
develop overnight, primarily east of a line from KPIA-KSPI.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 1 AM CDT Tuesday for ILZ027>031-036>038-
041>046-053-055-057.
Flood Watch until 1 AM CDT Tuesday for ILZ040-047>052-054-056-
061>063-066>068-071>073.

&&

$$

KEY MESSAGES...AAT
DISCUSSION...AAT
AVIATION...AAT