769
FXUS63 KILX 312302
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
602 PM CDT Fri May 31 2024

.KEY MESSAGES...

- Widespread showers and storms arrive late tonight with chances
  continuing through Saturday. Rainfall amounts look to range from
  0.5 to 1 inch, with a 20-30% chance for amounts exceeding 1
  inch.

- Additional chances for showers and storms are expected early
  next week, including the threat for some severe storms.

&&

.DISCUSSION...
Issued at 309 PM CDT Fri May 31 2024

Another pleasant and seasonable weather day is occurring across the
state this afternoon as we remain largely under high pressure. Cloud
cover has increased some since this morning as an upper wave over
the central Plains approaches from the southwest. Moisture transport
will increase ahead of the wave and eat away at mid-level dry air,
eventually leading to shower activity late tonight continuing into
Saturday. Lack of both instability and a pronounced upper jet will
prevent severe weather, however CAPE of a ~500 J/kg give or take
will support scattered thunderstorm activity. Precipitation totals
look to range from 0.5 to 1 inch areawide, though slightly higher
amounts over 1 inch will be possible with any thunderstorms. The NBM
highlights about a 20-30% chance of 1+ inch of rainfall.

Brief upper ridging will overspread the area going into the second
half of the weekend, putting an end to precipitation for Sunday.
Flow aloft becomes more zonal by the beginning of the new week,
allowing a series of upper waves to rotate through the area. Periods
of showers and storms become common Monday, looking to continue
through at least Midweek. A stronger wave will track from the
Pacific Northwest into the northern Plains/Canadian Prairies later
Monday into Tuesday, bringing what looks like a more active period
for the central US. At this point, the better jet dynamics look to
remain positioned to our west and northwest until later in the week,
which would imply less supportive wind shear. The CSU-MLP highlights
a few days with a 5-15% chance for severe weather next week, with
the highest probability being on Tuesday which is when a cold front
will approach from the west.

Temperatures will warm back near or slightly above normal for early
next week with dewpoints in the 60s to low 70s leading to a more
humid airmass. The Climate Prediction Center then favors below
normal temperatures for the end of next week into next weekend as
the early week system becomes occluded north of the Great Lakes
Region and pushes lower mid-level heights southward into the
region.

NMA

&&

.AVIATION...  (For the 00z TAFs through 00z Saturday Evening)
Issued at 602 PM CDT Fri May 31 2024

SHRA will advance northeast across central IL late tonight, and
continue off and on though Saturday afternoon. A few TSRA are
possible (20% chance) mainly Saturday afternoon but coverage too
low to include in TAFs. Ceilings and visibilities will drop to
MVFR with the rain, with transient periods of IFR ceilings in
heavier showers. After wind gusts diminish over the next hour or
two, southeast winds near 10 kt will persist through the forecast.

25

&&

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

$$