Severe Thunderstorm Warning 342, NWS Lincoln, IL

873 
WWUS53 KILX 111912
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
212 PM CDT Tue Aug 11 2026

ILC019-183-112000-
/O.CON.KILX.SV.W.0342.000000T0000Z-260811T2000Z/
Vermilion-Champaign-
212 PM CDT Tue Aug 11 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR NORTHERN VERMILION AND NORTHEASTERN CHAMPAIGN COUNTIES...

At 211 PM CDT, severe thunderstorms were located near Rankin and near 
Hoopeston, moving southeast at 45 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

This severe storm will be near...
  Hoopeston and Rossville around 215 PM CDT.

Other locations impacted by this severe thunderstorm include
Armstrong, Alvin, Penfield, Ludlow, Bismarck, Henning, and Collison.

This also includes Middle Fork State Fish and Wildlife Area.
 
This includes Interstate 57 between mile markers 254 and 257.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4012 8753 4040 8826 4040 8794 4049 8793
      4049 8753
TIME...MOT...LOC 1911Z 296DEG 37KT 4044 8779 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Auten

958 
WWUS53 KILX 111940
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
240 PM CDT Tue Aug 11 2026

ILC019-183-112000-
/O.CON.KILX.SV.W.0342.000000T0000Z-260811T2000Z/
Vermilion-Champaign-
240 PM CDT Tue Aug 11 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR NORTHERN VERMILION AND NORTHEASTERN CHAMPAIGN COUNTIES...

At 240 PM CDT, a severe thunderstorm was located over Potomac, or 12
miles southwest of Hoopeston, moving southeast at 45 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

This severe storm will be near...
  Danville and Vermilion Regional Airport around 250 PM CDT.

Other locations impacted by this severe thunderstorm include
Armstrong, Bismarck, Alvin, Penfield, and Henning.

This also includes Middle Fork State Fish and Wildlife Area.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4012 8753 4032 8804 4041 8754
TIME...MOT...LOC 1940Z 295DEG 38KT 4029 8776 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Auten

939 
WWUS53 KILX 111955
SVSILX

Severe Weather Statement
National Weather Service Lincoln IL
255 PM CDT Tue Aug 11 2026

ILC019-183-112005-
/O.EXP.KILX.SV.W.0342.000000T0000Z-260811T2000Z/
Vermilion-Champaign-
255 PM CDT Tue Aug 11 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN VERMILION AND
NORTHEASTERN CHAMPAIGN COUNTIES WILL EXPIRE AT 300 PM CDT...

The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

&&

LAT...LON 4012 8753 4032 8804 4041 8754
TIME...MOT...LOC 1955Z 296DEG 37KT 4023 8760 

$$

Auten

Area Forecast Discussion
National Weather Service Lincoln IL
1245 PM CDT Tue Aug 11 2026

.KEY MESSAGES...

- Highly conditional severe threat today, primarily along/north
  of I-74. Tracks and outflow evolution of an upstream MCS will
  dictate wind threat later this morning into afternoon.

- Unsettled "ring of fire" pattern persists through Thursday
  morning with intermittent thunderstorm chances and muggy
  conditions.

- Relief arrives late Thursday into Friday following a cold
  front. Cooler temperatures settle into the Midwest early next
  week.

&&

.DISCUSSION...
Issued at 344 AM CDT Tue Aug 11 2026

.UPDATE / NEAR TERM... (Today through Tonight)

Early morning water vapor imagery depicts multiple mid-level
shortwave impulses rippling through broad northwesterly flow
across the Upper Midwest. The most robust shortwave is currently
pushing into northwest Iowa and has already forced a cluster of
deepening convection. At the surface, a quasi-stationary
boundary remains draped along the I-80 corridor from central
Iowa into northwest Indiana.

The convective cluster pushing through Iowa early this morning
is the dominant feature driving SPC's Day 1 Enhanced Risk
(Level 3 of 5) across portions of northern and central Illinois.
However, considerable forecast uncertainty remains regarding
its upstream evolution--specifically how far south this MCS
will track as its cold pool matures over the state later this
morning.

Current observational trends suggest that the wind-driven
Enhanced Risk for today might be slightly baggy on its southern
fringe across the ILX CWA. The maturing upstream MCS seems
poised to advance east along I-80 throughout the morning, riding
the theta-e gradient of the stationary front that remains
rooted just north of our forecast area.

Overnight initiation along the WI/IL border has materialized as
of 3 AM, but satellite/radar trends show no sign of a strong
convective outflow pushing the effective boundary south of I-80.
Should this trend persist, it becomes increasingly unlikely
that the primary Iowa MCS will dive southeastward along the I-74
corridor by midday. Conversely, if the northern border
convection manages to lay out an effective boundary south of
I-80 over the next few hours, the local Enhanced Risk placement
will be validated.

The devil remains in the details today, and we will monitor the
southern flank of the incoming MCS closely. While recent CAMs
(notably the 06z HRRR) advocate for the MCS kicking an outflow
boundary south into central Illinois this afternoon yielding
explosive convective initiation across east-central Illinois we
are growing increasingly pessimistic about widespread secondary
development. Model soundings reveal substantial residual
capping, with parcels largely failing to reach convective
temperatures this afternoon. Furthermore, synoptic-scale
subsidence will overspread the area behind the departing
shortwave. Any surging outflow may struggle to break the cap or
overcome this broad suppression.

We caution against dismissing the Day 1 severe risk outright.
Ignoring the anomalous thermodynamics (MLCAPE >3500 J/kg) and
strong kinematic profiles in place would be meteorological
malpractice. It remains entirely possible that the core or
southern flank of the MCS clips the I-74 corridor through late
morning with severe wind gusts, or that isolated re-development
occurs along the outflow. However, today's risk is
extraordinarily conditional, and given the lack of overnight
outflow push, the overall probability of widespread, significant
wind damage across central Illinois is trending lower.

.LONG TERM... (Wednesday through Monday)

Regardless of whether today proves to be a convective bust
locally, the active ring of fire pattern will remain intact
through Thursday morning. Additional shortwave energy will
occasionally ripple across central Illinois along the lingering
baroclinic zone. Dewpoints pooling in the mid-70s, combined with
nighttime low-level jet (LLJ) veering over the surface
boundary, will sustain moderate buoyancy each night.
Intermittent overlaps of 25-35 kt deep-layer shear will keep an
organized severe weather threat in play through midweek.

By Thursday evening, a more defined, broad upper trough axis
will dig across the eastern Great Lakes, driving the surface
boundary south through our CWA as a cold front. This will flush
away the oppressive heat and high humidity, if only temporarily.
NBM guidance reflects afternoon highs dropping into the lower
80s by Friday.

This initial cooldown looks brief, as the frontal boundary
wavers back northward as a warm front Friday night into
Saturday. Showers and thunderstorms will likely accompany the
warm-frontal passage Saturday, with additional rain chances
arriving Sunday into Monday as a potent shortwave trough digs
across the Plains and drives a stronger cold front through the
region.

Despite nuance differences among medium-range guidance
regarding exact frontal timing over the weekend, models exhibit
strong consensus that a deeper continental polar (cP) air mass
will sweep into the Midwest by Monday and Tuesday, delivering a
much-needed, extended break from the active convective regime.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1245 PM CDT Tue Aug 11 2026

Complex of severe convection that tracked across northern
Illinois this morning has now curved southeastward into Indiana:
however, a prominent outflow boundary lingers near/north of the
I-74 corridor. Will be keeping an eye on that area over the next
few hours as scattered cells develop through the remainder of
the afternoon. Areal coverage on most CAMs remains scant, but
have opted to maintain the PROB30 for thunder at KPIA/KBMI/KCMI
through about 23z. These cells should dissipate and/or shift
into Indiana before sunset...followed by a mostly dry overnight
and early morning. It appears another complex of storms will
develop over Iowa late tonight into early Wednesday morning,
then take a similar albeit slightly further south track than the
storm complex earlier today. This would take the convection
across the heart of central Illinois from late Wednesday morning
through the afternoon. Plenty of questions in this scenario
remain, so confidence is low at this time. As such, have
generally followed the 12z RRFS solution and added a PROB30 for
thunder at only KPIA between 15z and 18z Wed.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT this evening for ILZ036-040>042-
047>054-056-061>063-066>068-071>073.

&&

KEY MESSAGES...MJA
DISCUSSION...MJA
AVIATION...Barnes

Hazardous Weather Outlook
National Weather Service Lincoln IL
1132 AM CDT Tue Aug 11 2026

ILZ027>031-036>038-040>042-047>051-121100-
Knox-Stark-Peoria-Marshall-Woodford-Fulton-Tazewell-McLean-Schuyler-
Mason-Logan-Cass-Menard-Scott-Morgan-Sangamon-
1132 AM CDT Tue Aug 11 2026

This Hazardous Weather Outlook is for central Illinois and west
central Illinois, mainly along and west of I-55.

.DAY ONE...This afternoon and tonight.

Scattered thunderstorms are expected into the evening hours, mainly
along and north of I-74. A few of these may contain damaging winds,
though the severe weather threat is not as high as earlier.

Heat index values of 100 to 105 degrees are expected today, primarily
south of I-74.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Heat indices of 95 to 105 degrees are expected Wednesday afternoon.

Daily chances for thunderstorms and heavy rain exist through the
weekend. Some of these storms could be severe through at least
Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed through sunset.

ILZ043>046-052>057-061>063-066>068-071>073-121100-
De Witt-Piatt-Champaign-Vermilion-Christian-Macon-Moultrie-Douglas-
Coles-Edgar-Shelby-Cumberland-Clark-Effingham-Jasper-Crawford-Clay-
Richland-Lawrence-
1132 AM CDT Tue Aug 11 2026

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

.DAY ONE...This afternoon and tonight.

Scattered thunderstorms are expected to develop over east central
Illinois by mid afternoon, with a risk developing in southeast
Illinois by early evening. These storms may be severe, with potential
for wind gusts in excess of 70 mph.

Outside of the storms, heat index readings of 100 to 105 degrees are
likely this afternoon.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Heat indices of 95 to 105 degrees are expected Wednesday and Thursday
afternoons, primarily south of I-70.

Daily chances for thunderstorms and heavy rain exist through the
weekend. Some of these storms could be severe through at least
Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed mid to late afternoon north of
I-70, and early this evening south of I-70.

Geelhart