Severe Thunderstorm Warning 294, NWS Lincoln, IL

Area Forecast Discussion
National Weather Service Lincoln IL
832 PM CDT Wed Jun 17 2026

.KEY MESSAGES...

- A Tornado Watch is in effect until 10pm CDT for locations
  along and south of a Macomb to Chenoa line. All severe hazards
  are possible...with the greatest probability for strong
  tornadoes focusing south of a Springfield to Paris line.

- Quiet weather will prevail Thursday through Saturday...with
  the next chance for thunderstorms arriving by Sunday.

&&

.UPDATE...
Issued at 832 PM CDT Wed Jun 17 2026

The severe threat has drifted near and south of I-72/Danville
now. We are still expecting potentially strong to intense, long
track tornadoes, very large hail, and damaging wind gusts of
75+ mph for the next few hours. Remain weather aware and know
where your safe shelter is.

If you are north of a Cass County to Dewitt County line, you
should be in the clear for this event.

&&

.DISCUSSION...
Issued at 316 PM CDT Wed Jun 17 2026

19z/2pm mesoanalysis shows an outflow boundary left behind by
the morning convection along a Quincy...to Litchfield...to
Salem line. This is considerably further south than previously
thought: therefore the most significant risk for widespread
severe weather later this afternoon and evening has shifted
south as well. As such, the new Tornado Watch coordinated with
SPC does not include the far northern KILX CWA from the Peoria
area northward.

MLCAPEs are currently under 1000J/kg: however, as the boundary
mixes slowly northward this afternoon, the RAP suggests MLCAPEs
will increase into the 1500-2000J/kg along/southeast of a Quincy
to Champaign line over the next couple of hours. Impressive wind
fields aloft are contributing to very strong 0-6km bulk shear
of 60-80kt...while 0-1km shear values remain in the 30-40kt
range. Given marginal instability and extreme shear, am
expecting supercell thunderstorms to rapidly develop along/ahead
of a slowly advancing cold front across the Illinois River
Valley imminently. All severe hazards will be in play...including
damaging wind gusts in excess of 70mph, hail larger than
golf balls, and tornadoes. The Significant Tornado Parameter
(STP) is currently maximized closer to the outflow boundary
from central/northern Missouri across south-central Illinois,
but is progged to lift northward later this afternoon/evening.
At this time, it appears the highest probability of potentially
strong tornadoes will focus along/south of a Springfield to
Paris line.

Thunderstorms are currently developing in a band from
Galesburg/Rushville eastward to Pontiac/Champaign. CAMs have
generally sped up the development process, as well as the
gradual S/SE movement of the band. As a result, think the
primary severe risk will be focused along the I-72 corridor
between 4pm and 6pm, then will sink toward I-70 by 7pm to 9pm.
The primary line of convection will exit the far SE KILX CWA
around midnight: however, a few showers may linger further north
throughout the evening into the first part of the overnight.

A short-wave trough will bring a period of mid-level cloudiness
to central Illinois Thursday morning, with forecast soundings
suggesting the potential for a few light rain showers mostly
along/south of a Rushville to Robinson line where slight chance
PoPs (20%) are warranted. Once this wave departs, a return to
cool and mostly dry weather will be on tap for Friday and
Saturday. The next significant chance for precipitation will
hold off until late Saturday night into Sunday as a stronger
short-wave trough traverses the Plains and approaches from the
west. Given better deep-layer moisture and strong forcing, think
showers and thunderstorms will become widespread. The severe
weather risk remains uncertain at this time, with several
machine learning algorithms such as Colorado State and NSSL
keeping the greatest probabilities further south. A few NCAR
members do however suggest 15-30% probs northward into central
Illinois, so will need to keep an eye on mesoscale details as
the time nears.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 629 PM CDT Wed Jun 17 2026

A line of scattered but intense convection located along the
I-72 corridor will continue to gradually push east-southeast of
the terminals through about 02-04z. Convective impacts will be
greatest at SPI, DEC, and CMI, where brief LIFR vsbys and
variable and gusty thunderstorm winds are expected. Skies will
gradually clear overnight, with winds become steady from the W
to WNW around 8-12 kts. After 12z, diurnal CU with bases around
5kft will develop with steady NW around 10-15 kts.

&&

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

&&

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

Hazardous Weather Outlook
National Weather Service Lincoln IL
328 PM CDT Wed Jun 17 2026

ILZ036>038-040>057-061>063-066>068-071>073-181100-
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-
328 PM CDT Wed Jun 17 2026

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

.DAY ONE...Tonight.

A broken line of thunderstorms capable of all severe hazards will
settle southward through central Illinois late this afternoon and
evening. The strongest cells within the line will have the potential
to produce tornadoes, damaging wind gusts in excess of 70mph, and hail
large than golf balls. The highest probability for strong tornadoes
will focus along and south of a Springfield to Paris line.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Thunderstorms will develop across the area late Saturday night into
Sunday. At this time it appears the severe weather risk will remain
low.

River flooding is ongoing for portions of central Illinois. Please
refer to the latest flood statements for details.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed through 10pm this evening.

Expected storm motion is toward the east at 60-70mph.

ILZ027>031-181100-
Knox-Stark-Peoria-Marshall-Woodford-
328 PM CDT Wed Jun 17 2026

This Hazardous Weather Outlook is for central Illinois and west
central Illinois.

.DAY ONE...Tonight.

A few strong to severe thunderstorms capable of damaging wind gusts
and large hail will track across north-central Illinois late this
afternoon. The storms will drop south of the Peoria area by early
evening.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Thunderstorms will develop across the area late Saturday night into
Sunday. At this time it appears the severe weather risk will remain
low.

River flooding is ongoing for portions of central Illinois. Please
refer to the latest flood statements for details.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed through 5pm this afternoon.

Expected storm motion is toward the east at 60-70mph.

Barnes

Preliminary Local Storm Report
National Weather Service Lincoln IL
833 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 PM     Rain             2 ENE Urbana            40.11N 88.18W
06/17/2026  M1.40 Inch       Champaign          IL   Public

            Rainfall so far today.

&&

07

Preliminary Local Storm Report
National Weather Service Lincoln IL
838 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0644 PM     Hail             3 N Humboldt            39.64N 88.32W
06/17/2026  M3.00 Inch       Coles              IL   Public

            Relayed via social media.

&&

Preliminary Local Storm Report
National Weather Service Lincoln IL
839 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0822 PM     Tornado          2 SW Montrose           39.15N 88.40W
06/17/2026                   Effingham          IL   Broadcast Media

            Homes damaged from a tornado southwest of
            Montrose.

&&

Preliminary Local Storm Report
National Weather Service Lincoln IL
842 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0646 PM     Hail             Humboldt                39.61N 88.32W
06/17/2026  M2.50 Inch       Coles              IL   Public

            Relayed via social media.

&&

Preliminary Local Storm Report
National Weather Service Lincoln IL
845 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0450 PM     Hail             1 W Illiopolis          39.85N 89.26W
06/17/2026  M1.75 Inch       Sangamon           IL   Public

            Report from mPING: Golf Ball (1.75 in.).

&&

07

Preliminary Local Storm Report
National Weather Service Lincoln IL
848 PM CDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0551 PM     Hail             Decatur                 39.84N 88.95W
06/17/2026  E0.75 Inch       Macon              IL   Public

            Report from mPING: Dime (0.75 in.).

&&

07