240
FXUS63 KILX 022347
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
547 PM CST Mon Nov 2 2026

.KEY MESSAGES...

- Strong southerly winds will gust 30 to 40 mph at times on
  Tuesday, with a 30 to 50% chance of reaching advisory criteria
  (gusts of 45 mph or higher) north of I-70.

- Scattered thunderstorms Tuesday afternoon and evening could
  produce localized damaging wind gusts, even with little or no
  lightning.

- Widespread rainfall amounts of 0.75 to 1.50 inches are
  expected Tuesday through Wednesday night, with a 10% chance of
  localized totals reaching 2.0 to 2.5 inches.

&&

.DISCUSSION...
Issued at 1252 PM CST Mon Nov 2 2026

     NEAR TERM (TODAY THROUGH TUESDAY)...
A pair of potent mid-level shortwaves -- one situated over the
Desert Southwest and another over North Dakota -- will drive a
slow-moving surface low and cold front across the region through
the first half of the week. Surface analysis this afternoon
shows a 996 mb low over northeastern South Dakota, with a trough
axis extending southwestward into a second low center of 998 mb
over western Kansas. Strong southwesterly flow ahead of these
synoptic features is fueling robust warm and moist advection
across the Midwest.

South-southeast winds gusting 20 to 30 mph today will boost
temperatures into the mid 60s today. Highs will warm further
into the low to mid 70s Tuesday as the pressure gradient
tightens. Southerly wind gusts on Tuesday may approach 40 mph at
times, with NBM probabilities for gusts exceeding 40 mph
ranging from 50 to 70% across a significant portion of the CWA.
The probability of reaching Wind Advisory criteria (45 mph
gusts) is roughly 30 to 50% north of I-70. While confidence is
currently insufficient to issue a Wind Advisory, a few localized
sites may tag criteria. Meanwhile, sustained moisture transport
will push surface dewpoints into the low to mid 60s by Tuesday
afternoon.

     SEVERE WEATHER THREAT (TUESDAY AFTERNOON & EVENING)...
As the elongated, double-barrel surface low lifts across the
mid and Upper Mississippi Valley Tuesday afternoon, weak
instability is forecast to overspread portions of central
Illinois. This instability will be superimposed by strong deep-
layer shear of 40 to 50 kt, supporting a conditional severe
weather threat Tuesday afternoon and evening should localized
cloud breaks allow for greater surface heating. Even without
robust convective updrafts or lightning, the intense background
synoptic flow within the cloud-bearing layer could easily be
transferred to the surface, resulting in near-severe or
marginally severe wind gusts in convective downdrafts.

     HEAVY RAIN & HYDROLOGY (TUESDAY THROUGH WEDNESDAY)...
Precipitable water values exceeding 1.50 inches pooling along
the frontal zone approach maximum values in the 1985-2012 GEFS
reforecast climatology. High rainfall efficiency is expected as
a slow-moving band of showers and isolated embedded
thunderstorms traverses the forecast area Tuesday into
Wednesday. The 48-hour NBM mean QPF through Wednesday night
indicates widespread totals of 0.75 to 1.50 inches, with 90th
percentile ensemble guidance highlighting localized totals up to
2.0 to 2.5 inches.

     EXTENDED PERIOD (THURSDAY THROUGH SUNDAY)...
Cold frontal passage will bring an end to widespread moderate-
to-heavy precipitation by late Wednesday night as the surface
low gradually fills and meanders across the Great Lakes.
Persistent low-level cyclonic flow and wrap-around moisture
within post-frontal cold air advection (CAA) will maintain cloud
cover along with scattered sprinkles or light showers Thursday
through Saturday, particularly as shortwave vorticity lobes
pinwheel southward around the departing upper trough. Post-
frontal high temperatures Friday through the weekend will cool
into the 50s, which remains near seasonal normals. Recent GFS
and ECMWF guidance is showing better consensus regarding a fast-
moving shortwave diving across the region on Sunday, bringing
the next opportunity for more widespread light precipitation.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 547 PM CST Mon Nov 2 2026

IFR conditions prevail at the central Illinois terminals late
this afternoon. Radar/local obs show patchy drizzle and reduced
visbys down to 2-3 miles in a few spots...and this should
continue for the next couple of hours before the drizzle lifts
slowly northward out of the area by mid-evening. While low
clouds currently dominate, ceilings improve markedly further
south near/south of I-64. All models suggest the continued
strong SE boundary layer flow will eventually lift these
improved conditions into central Illinois later this evening
through the overnight hours. Based on the most recent HRRR/RAP,
have improved ceilings to low VFR at KDEC/KCMI by 06z...then
further northwest to KPIA by around 10z. A cold will slowly
approach from the west on Tuesday, spreading low clouds and
showers into the area as the day progresses. Forecast soundings
indicate a return to MVFR across the board between 13z and 15z.
Showers will primarily impact the western terminals, so have
opted to leave rain mention out of KDEC/KCMI through 00z Wed.
Winds will initially be SE with gusts of 20-25kt tonight, then
will become S with gusts of 25-30kt on Tuesday.

&&

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

&&

$$

KEY MESSAGES...Deubelbeiss
DISCUSSION...Deubelbeiss
AVIATION...Barnes