Hail and Damaging Wind in Illinois, April 27, 2026

Area Forecast Discussion
National Weather Service Paducah KY
254 AM CDT Mon Apr 27 2026

.KEY MESSAGES...

- A significant severe weather event remains on track late this
  afternoon into tonight. Strong tornadoes, very large hail, and
  damaging winds are all possible. An initial area of showers
  and thunderstorms will move through the Quad State this
  morning, then there will be a break this afternoon before the
  primary severe weather episode begins.

- Breezy conditions are expected today with wind gusts 25-40
  mph. A Wind Advisory for gusts over 40 mph may need to be
  issued this afternoon (~50% chance).

- Another round of severe storms is possible late Tuesday
  afternoon into Tuesday night. Very large hail (>2") and
  damaging winds are the primary threats, but a few tornadoes
  cannot be ruled out.

- It will be warm again today, but the early rainfall could hold
  high temperatures down by a few degrees from previous forecast
  levels. Temperatures will trend down to normal or just below
  for Wednesday into next weekend.

&&

.DISCUSSION...
Issued at 254 AM CDT Mon Apr 27 2026

A cluster of convection over east central Missouri will move
eastward over the northern half of the Quad State in the next
few hours. It should be running out of any significant
instability, so a weakening trend is expected. The latest HRRR
shows the northern portion of the cluster dissipating over
southern Illinois by daybreak. It also develops another line of
storms that moves southeast through southeast Missouri through
daybreak. This area continues into west Kentucky and eventually
dissipates over the Pennyrile later this morning. Surface-based
instability will be limited to under 500J/kg, so the storms will
most likely be elevated. Torrential rainfall and lightning
should be the primary concerns, but some hail cannot be ruled
out.

There is plenty of flow and forcing for the air mass to recover
over the Quad State behind this morning's system. As the
associated MCV continues east, subsidence should help to limit
convection over the Quad State until close to 00Z. Most of the
00Z and later CAM data develops scattered supercells along the
cold front/dryline to the west of the area late this afternoon.
The environment is forecast to be absurdly strong with CAPE
over 3000J/kg and 0-3km SRH 300-400m2s2. The RRFS has STP values
from 5-10 over southeast Missouri. The general trend in the
CAMs is for storms to remain discrete or possibly form into
short line segments where they can hold onto their supercellular
characteristics. This will lead to a very large hail and strong
tornado (up to EF-3) threat. The worst conditions are expected
over southeast Missouri and southern Illinois, but the
instability drops off considerably over southwest Indiana and
the Pennyrile in west Kentucky, so the storms should weaken as
they move into our eastern counties in the late evening or
overnight hours.

The 00Z ECENS has a 90% or greater chance of wind gusts reaching
at least 40 mph this afternoon and it usually verifies well.
However, given the early morning convection, we decided to cap
gusts to 39 mph for now and wait and see how this evolves later
this morning. The day shift can re-evaluate the need for a Wind
Advisory later today.

The 00Z guidance continues to bring a surface wave through the
Quad State late Tuesday and Tuesday night. Strong instability is
expected to develop and the shear has increased sufficiently to
support another round of severe storms. There should be steep
lapse rates in the low and mid-levels and some substantial
downdraft CAPE, so large hail and damaging winds are a strong
possibility. There may even be a tornado threat, as there are
indications that the low-level shear could increase
significantly in the evening.

With three rounds of storms possible through Tuesday night, 2-3"
of rainfall is expected, and some localized higher amounts are
possible. This should certainly help the drought conditions
across the region, but some isolated flash flooding concerns
could develop where the heaviest rain falls.

We should be dry with north winds by daybreak Wednesday.
Temperatures will drop to normal or below through at least
Saturday, and no precipitation is expected. The NBM still has
some 20-30% PoPs in the south Friday, but the 00Z guidance
keeps that precipitation to the south of the Quad State. There
is no QPF.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1148 PM CDT Sun Apr 26 2026

On and off shra/tsra possible through the TAF period, with
timing of best chances very challenging. Shra and isolated/scattered
tsra possible near KCGI/KPAH/KMVN after 11z, with a lull late
morning. More isolated activity expected at KEVV/KOWB. At all
sites, chances increasing late afternoon and especially after
00z, with strong to severe storms possible with gusty winds.
MVFR/IFR vsbys likely with storms, and MVFR cigs possible. Away
from convection, VFR conditions expected with south/southeast
winds around 10kts increasing to 12-18kts with gusts around
25kts, shifting to southwest after 00z.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.

&&

DISCUSSION...DRS
AVIATION...RST

Hazardous Weather Outlook
National Weather Service Paducah KY
320 AM CDT Mon Apr 27 2026

ILZ075>078-080>094-INZ081-082-085>088-KYZ001>022-MOZ076-086-087-
100-107>112-114-281000-
Jefferson-Wayne IL-Edwards-Wabash-Perry IL-Franklin-Hamilton-
White-Jackson-Williamson-Saline-Gallatin-Union-Johnson-Pope-
Hardin-Alexander-Pulaski-Massac-Gibson-Pike-Posey-Vanderburgh-
Warrick-Spencer-Fulton-Hickman-Carlisle-Ballard-McCracken-Graves-
Livingston-Marshall-Calloway-Crittenden-Lyon-Trigg-Caldwell-
Union KY-Webster-Hopkins-Christian-Henderson-Daviess-McLean-
Muhlenberg-Todd-Perry MO-Bollinger-Cape Girardeau-Wayne MO-Carter-
Ripley-Butler-Stoddard-Scott-Mississippi-New Madrid-
320 AM CDT Mon Apr 27 2026 /420 AM EDT Mon Apr 27 2026/

This Hazardous Weather Outlook is for portions of southern
Illinois, southwest Indiana, western Kentucky, and southeast
Missouri.

.DAY ONE...Today and Tonight

An initial round of thunderstorms will move through mainly
southeast Missouri and west Kentucky this morning. Torrential
rainfall and lightning will be the primary concerns, but some
hail cannot be ruled out.

Scattered to numerous severe storms are expected mainly this
evening. Very large hail, greater than golfball size, strong
tornadoes, and damaging winds will be possible. The greatest
threat seems to be in southeast Missouri and southern Illinois
this evening.

Any storm today and tonight will produce torrential rainfall. A
flash flood threat could develop in areas that receive multiple
storms.

South winds will gust 25-40 mph this afternoon into the early
evening.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Numerous strong to severe storms are expected late Tuesday and
Tuesday night. Very large hail and damaging winds will be the main
concerns, but a few tornadoes cannot be ruled out. Torrential
rainfall could lead to an isolated flash flood threat.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed throughout the Quad State
late this afternoon and this evening. Activation cannot be ruled
out for a few hours this morning, as well. Activation throughout
the region may be needed again late Tuesday and Tuesday night.