922
FXUS63 KILX 111738
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1238 PM CDT Sat May 11 2024

.KEY MESSAGES...

- The weekend is panning out to be dry and pleasant with increasing
  warmth through Sunday.

- Soaking rains and a few storms return on Monday and linger
  through Tuesday. There remains a 40-60% chance that rainfall
  totals will reach around one inch during that time, which could
  send a few rivers toward bank full.

&&

.UPDATE...
Issued at 1023 AM CDT Sat May 11 2024

At 10:15am, visible satellite showed clear skies across central
Illinois, which has resulted in a rapid rise in temps this morning
favoring highs a smidgen warmer than previously forecast; that was
updated using the latest iteration of the HRRR which seems to be
handling mixing/insolation well. The wind forecast was nudged up a
hair also, given ASOS observations show gusts already
approaching/reaching 30 mph and BUFKIT soundings suggest mixing
will only deepen (though winds aloft will simultaneously weaken)
through early afternoon when top of mixed layer (800-750mb, per
NAM and GFS forecast soundings) winds are in the 35-40mph range.
We`ll likely have frequent northwesterly gusts around 25-33 mph
this afternoon, making the airmass feel a little chillier than
temps alone would suggest.

Bumgardner

&&

.DISCUSSION...
Issued at 234 AM CDT Sat May 11 2024

The latest IR satellite images show a band of mid clouds drifting
south through Illinois as a cold front traverses the area. The
aurora was still visible through the clouds, as an impressive G5
solar storm impacts the CONUS.

As for precip along the cold front, showers have been spotty to
say the least with the dry airmass limiting any measurable rain
in most of the area. Those showers should depart into Indiana by
sunrise or shortly after, with nearly full sunshine this morning.
Deep mixing will dry out the air today, as surface dewpoints dip
into the lower 40s. However, afternoon cumulus will redevelop due
to steeper low level lapse rates in the post-cold frontal
airmass. Northwest wind gusts will top out in the 25 to 30 mph
range early this afternoon, adding a cooler feel to this below
normal temperature day.

Southerly return flow on Sunday will help boost high temps into
the low 80s west of I-55, with upper 70s east of I-55. Surface
dewpoints will make a return to the 50s, in preps for the onset of
the next wave of rain early Monday morning. Surface cyclogenesis
will develop over the central Plains as a cold front makes
southward push from the upper Midwest toward the Ohio River
Valley. The two will intersect as the low reaches southern
Illinois late Monday night into Tuesday, setting the stage for
wetting rains much of the day and night Monday. QPF totals in that
24 hour period look to climb over 0.75" in most of central IL (70%
chance). Instability params are marginal for thunder for most of
the day Monday, but increase Monday night into Tuesday as frontal
convergence increases and mid-level lapse rates steepen. Severe
weather potential appears low amid weaker shear profiles, and a
triple point that passes well to the south of IL.

Our coolest day of the next week will be Tuesday, as highs remain
in the 60s north of I-70 (70-80% chance per DESI Grand Ensemble).

The break in the rain Wednesday will be short-lived as the next
frontal system progresses through the mid-Mississippi River Valley
area Thursday and Friday. Rain and storm chances late week will
keep the recent wet trends in full swing.

Shimon

&&

.AVIATION...  (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1233 PM CDT Sat May 11 2024

VFR conditions will continue through the forecast period, with
diurnal cumulus, along with northwest winds gusting to 25 kt,
diminishing after sunset this evening. Tomorrow, low level winds
will turn to southerly, gusting 15-20 kt near the end of the
forecast period.

Bumgardner

&&

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

$$