Flash Flood Warning 51, NWS Lincoln, IL

Area Forecast Discussion
National Weather Service Lincoln IL
653 PM CDT Mon Jul 27 2026

.KEY MESSAGES...

- Oppressive heat and humidity continues through early evening
  with heat indices peaking between 105 and 115 degrees.

- Multiple thunderstorm complexes will move across IL this
  afternoon/evening, presenting a conditional threat for severe
  weather. Damaging winds (60-70+ mph gusts) and heavy rains
  are a risk especially in eastern and southeastern IL this
  afternoon and early evening.

- A cold front will bring relief from the high heat and humidity on
  Tuesday, transitioning us back to near normal temperatures
  and humidity levels during mid week.

&&

.DISCUSSION...
Issued at 218 PM CDT Mon Jul 27 2026

Outside of the storm risk today, it has been very hot and humid
today. Heat indices have been around 100-105 so far but still have
time to increase to about 115 degrees in some spots. The Extreme
Heat Warning continues until tonight at 9 pm. If thunderstorms
materialize and move in during the afternoon and early evening, it
would cool temps/heat indices and would likely end the heat
headlines earlier than 9 pm. Beyond today, temperatures become more
seasonable and less humid with highs in the 80s and lows in the 60s
through next week.

Today's forecast has been a doozy. The models haven't been of the
greatest assistance recently with this round of convection. We have
an Enhanced Risk (level 3 of 5) for areas near and north of a Henry
to Marshall line and a Slight Risk (level 2 of 5) elsewhere for
today. Primarily this risk is for damaging winds, potentially
stronger than 70 mph, but there is also a 2% tornado risk for the
area within the Enhanced Risk.

Our 12z sounding shows MUCAPE over 5500 J/kg, effective shear of ~50
knots, and PWATs of nearly 2 inches. A shortwave is pulsing through
this afternoon across Illinois and Indiana, based off GFS 500 mb
vorticity. The storms currently over the Chicago-Land area may clip
eastern IL as it drops south into Indiana and they are evolving into
a damaging wind threat as it transitions to a linear mode rather
than supercellular. It is starting to trend towards areas west of I-
55 may not see any of the severe threat today. There may be some
showers/storms that direction but it looks like the main show will
remain east of I-55 this afternoon/evening. An additional wave may
move behind it that will also drop south, potentially riding the
IL/IN border, but could possibly be weaker in strength, based off
the HRRR. The HRRR's 16z and 17z runs are picking up the active
convection well. The storms should have exited by 10 pm tonight.
Storms will be moving to the south-southeast at 30-40 mph this
afternoon/evening.

The next chance for showers and thunderstorms comes in on Friday
into Saturday as a shortwave moves through the area.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 653 PM CDT Mon Jul 27 2026

2330z/630pm radar imagery shows the bulk of the convection well
E/SE of the central Illinois terminals. With the synoptic cold
front still to the NW across eastern/southern Iowa, an isolated
shower or thunderstorm will remain possible through the
remainder of the evening. Current satellite trends show mostly
clear skies along/ahead of the front: however, the HRRR/RAP have
been consistently showing a few cells popping along the front
later this evening. Confidence for thunder is low, so have only
mentioned VCSH between 03z and 09z. Once the front passes, winds
will veer to the N/NW late tonight, then to the N/NE Tuesday
morning. Skies will be mostly clear overnight, but low clouds
poised upstream across the Great Lakes will filter southwestward
into the area on Tuesday. Some guidance shows low MVFR ceilings,
but other models such as the HRRR and NAM suggest the clouds may
be MVFR. Given low confidence at that time range, have
introduced SCT015 BKN035 after the 12z-14z time frame.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 9 PM CDT this evening for
ILZ027>031-036>038-040>057-061>063-066>068-071>073.

&&

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

Hazardous Weather Outlook
National Weather Service Lincoln IL
226 PM CDT Mon Jul 27 2026

ILZ027>031-036>038-040>057-061>063-066>068-071>073-281930-
Knox-Stark-Peoria-Marshall-Woodford-Fulton-Tazewell-McLean-Schuyler-
Mason-Logan-De Witt-Piatt-Champaign-Vermilion-Cass-Menard-Scott-
Morgan-Sangamon-Christian-Macon-Moultrie-Douglas-Coles-Edgar-Shelby-
Cumberland-Clark-Effingham-Jasper-Crawford-Clay-Richland-Lawrence-
226 PM CDT Mon Jul 27 2026

This Hazardous Weather Outlook is for central Illinois, east
central Illinois, southeast Illinois and west central Illinois.

.DAY ONE...Tonight.

Heat index values of 105 to 115 degrees will continue into this
evening, then ease overnight.

Scattered storms are expected across portions of east central
Illinois east of I-57 with isolated storms possible west of I-57.
A few storms will be capable of producing wind gusts in excess of 70
mph. Isolated large hail and a brief tornado are also possible.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Scattered thunderstorms are expected from Thursday night into
Saturday. The severe weather threat appears low at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and evening.

Expected storm motion is toward the southeast around 35 mph.

Deubelbeiss

Special Weather Statement
National Weather Service Lincoln IL
426 PM CDT Mon Jul 27 2026

ILZ051>053-272200-
Sangamon-Macon-Christian-
426 PM CDT Mon Jul 27 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN CHRISTIAN...
NORTHEASTERN SANGAMON AND SOUTHWESTERN MACON COUNTIES THROUGH 500 PM
CDT...

At 425 PM CDT, Doppler radar was tracking a strong thunderstorm over
Buffalo, or 13 miles east of Springfield, moving southeast at 35 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Taylorville, Rochester, Riverton, Kincaid, Blue Mound, Edinburg,
Stonington, Illiopolis, Niantic, Mechanicsburg, Dawson, Buffalo,
Mount Auburn, Jeisyville, Spaulding, Clear Lake, Willeys, Sharpsburg,
Taylorville Municipal Airport, and Langleyville.

This includes Interstate 72 between mile markers 105 and 128.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3984 8959 3993 8941 3992 8940 3992 8921
      3966 8903 3949 8935
TIME...MOT...LOC 2125Z 324DEG 32KT 3984 8942

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Copple