416
FXUS63 KILX 150535
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1235 AM CDT Sun Mar 15 2026

.KEY MESSAGES...

- Severe weather is possible Sunday afternoon and evening, with
  the greatest threat near and east of Interstate 55. Damaging
  winds potentially exceeding 75 mph and a few tornadoes are the
  primary hazards.

- A sharp transition from rain to snow occurs Sunday night behind
  a strong cold front, accompanied by wind gusts over 40 mph and
  rapidly falling temperatures. Snow accumulations are possible
  with the highest probabilities of exceeding 2 inches focused
  near and west of the Illinois River.

- Subfreezing high temperatures and minimum wind chills between 0
  and -10 degrees are expected Monday and Tuesday mornings before
  a significant warming trend takes over for the last half of the
  new week.

&&

.DISCUSSION...
Issued at 217 PM CDT Sat Mar 14 2026

Surface analysis early this afternoon shows surface high pressure
centered over lower Michigan/Ohio with breezy east-southeast winds
across central Illinois. Mostly cloudy skies have kept temperatures
a few degrees cooler than originally anticipated with highs expected
to top out in the upper 40s to middle 50s. A deepening surface low
will track from the central Plains into the Great Lakes Region on
Sunday, bringing a period of impactful weather Sunday through Monday.

Strong southerly winds will develop out ahead of an approaching cold
front on Sunday with high probabilities for gusts to exceed 40 mph
through Sunday night. A warm, moist airmass will advect northward
during the day with high temperatures expected to climb into the 60s
to low 70s. Periods of showers and thunderstorms will begin as early
as mid to late morning, though the threat for strong to severe
storms increases later Sunday afternoon/evening with the arrival of
the cold front. The latest suite of CAMs shows a line of
thunderstorms developing in west-central Illinois between 19-21Z as
a strengthening mid-level jet begins rounding the base of a trough,
further increasing deep layer shear. Although dewpoints in the 50s
will limit instability (<1000 J/kg MLCAPE), robust deep layer shear
and strong kinematics will favor a squall line/QLCS event, with
damaging winds and tornadoes being the primary hazards through the
evening. The highest threat will be east of I-55 where an Enhanced
risk for severe storms (level 3 of 5) is in place.

Behind the front, strong cold air advection will transition
precipitation to snow Sunday night within the lows deformation
zone. Accumulating snow continues to be a possibility with about a
50-70% chance for seeing at least 2 inches near and west of the
Illinois River, with lesser amounts further east and southeast.
Strong west- northwest winds on the backside of the departing low
will significantly reduce visibility where snow is falling,
resulting in hazardous travel conditions. A winter weather
headline may be needed for counties near and west of the Illinois
River where the highest accumulations are forecast.

Much colder air filters in behind the system for Monday and Tuesday
with ECMWF EFI showing values around -0.8, which indicates an
unseasonably anomalous event. Temperatures will be coldest Monday
night with values falling into the single digits to teens. Breezy
winds during this period will send wind chills below zero for
western parts of the state Monday morning and for most Tuesday
morning.

A quick hitting clipper system may bring another shot of wintry
precipitation Tuesday night, possibly resulting in minor snow
accumulations. Temperatures will moderate by midweek then surge well
above normal late in the week into next weekend as upper ridging
over the western CONUS amplifies, allowing mid-level heights to
quickly rise over the Midwest states.

NMA

&&

.AVIATION...  (For the 06z TAFs through 06z Sunday Night)
Issued at 1235 AM CDT Sun Mar 15 2026

All sites will start as VFR with mid level cigs around 12-15kft.
HiRes models show a narrow line of sub severe showers and
scattered storms moving across all sites in the morning. Cigs
could drop to MVFR around 2.5kft with these storms and have a 2hr
PROB30 group at PIA and BMI. Only VCSH for SPI, DEC, and CMI with
no MVFR cigs. All sites will have MVFR cigs for late morning and
afternoon, but when main line of storms develops and moves through
each site, have a 3hr TEMPO group at each site with very high
winds, vis around 1sm and cigs below 1kft. After storms, rain/snow
mix is possible at all sites, but have no reduction in vis and
lower MVFR cigs. Winds will continue to increase in speed out of
the southeast, then become southerly for most of the day, then
westerly after the front/storms moves through. Gusts will be very
high just ahead of the afternoon storms and behind in the evening.


Auten

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 10 AM this morning to 7 AM CDT Monday for
ILZ027>031-036>038-040>057-061>063-066>068-071>073.

&&

$$