Area Forecast Discussion
Issued by NWS Central Illinois

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735
FXUS63 KILX 141057
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
557 AM CDT Fri Aug 14 2026

.KEY MESSAGES...

- Flash flooding is a concern along and north of the I-74
  corridor ongoing. Some locations have received 2-4 inches so
  far.

- There is an area of convection moving south across central and
  southeastern IL this morning that poses a heavy rain and
  damaging wind threat. The next round of convection will move
  in late this evening into the overnight hours. A slight risk
  for severe weather is in place for the northwestern part of
  our CWA from the SPC.

- Heat index values of 105 to 110 degrees will continue into the
  weekend each afternoon, in areas near and south of I-72. The
  heat is expected to spread northward across the forecast area
  by Saturday.

&&

.DISCUSSION...
Issued at 152 AM CDT Fri Aug 14 2026

The next round of heavy rain and strong storms have entered the
northern part of the CWA. It will continue to sink southward
throughout the overnight hours into the morning. The environment is
still quite unstable and as these storms push south, they should
move into an area of stronger CAPE values. Effective wind shear is
around 45 knots as of the most recent mesoanalysis from SPC where
the storms are located. Damaging winds is the main concern with the
strongest storms, but some small hail is possible as well.
The next round of convection will move in late this evening
into the overnight hours. A slight risk for severe weather is in
place for the northwestern part of our CWA from the SPC.

Along with the severe risk, we are also concerned for some flooding.
There is a flood watch out until 15z this morning. PWATs are around
2-2.2 inches. We have been quite saturated as of late. Some areas
cannot take much more without becoming inundated. Along and north of
I-74, the FFG is much lower (6 hr: 2-2.5 inches, 3 hr: 1-2.5 inches)
than in the southern half of the CWA, since they have received much
of the rain in the last day or so. The area around I-74 to Danville
has gotten ~2-5 inches of rain in the last 24 hours based off of
MRMS estimates. WPC has put our northwestern counties in a moderate
risk ERO today.

Temperatures remain hot as we make our way into the weekend. There
is a heat advisory for Scott County to Clark County (and south) that
is valid through Sunday. Further expansion north of the
advisory is possible as we go forward in time and get a better
grasp of how the next few rounds of MCS activity will evolve,
both spatially and temporally. Heat indices of 100-110 degrees
are forecast through Sunday, but how far north these heat
indices get will depend solely on the convection.

There is a marginal risk for severe weather again tomorrow area-wide
and again on Sunday for areas south of a Schuyler to McLean County
line with a similar environment in place as previous days. The
forecast will continue to evolve as we get newer runs of the models.

Next week may bring us a break in the active weather and the heat
briefly. Some guidance suggests a high pressure area setting up
over the Upper Mississippi Valley / Great Lakes region by
Monday, behind a cold front that is set to move through central
IL during the day. Temperatures starting Monday into much of the
next week will be mainly in the upper 70s to 80s for highs and
60s to low 70s for lows.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 557 AM CDT Fri Aug 14 2026

IFR ceilings are in place at KPIA-KBMI and are expected to
remain through mid-late morning, then MVFR through much of the
afternoon. Periods of TSRA with locally heavy rain and gusty
winds will affect the terminals through mid-late morning, with
bouts if IFR-LIFR under the more intense storms. Much of the
rest of the day will be VFR with light (and at times, variable)
winds. The next complex of thunderstorms will move in overnight
tonight, mainly affecting PIA and BMI within the 12z period.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 10 AM CDT this morning for ILZ027>031-037-
038-045-046.
Heat Advisory until 8 PM CDT Sunday for ILZ049>052-061>063-
066>068-071>073.

&&

$$

KEY MESSAGES...Copple
DISCUSSION...Copple
AVIATION...Copple