962
FXUS63 KILX 010433
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1133 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.

&&

.UPDATE...
Issued at 808 PM CDT Fri May 31 2024

Regional radar mosaic showed a large area of showers over central
and eastern MO, associated with a slow moving shortwave pushing
east from the central Plains. Leading edge of ascent will work to
saturate a deep dry layer between 850-500 mb noted on the 00z ILX
sounding. Thus the northeastward advance of the steadier showers
will be slow tonight, but eventually overspreading much of the CWA
by sunrise. Steady southeast winds, lowering/thickening clouds,
and rising dewpoints will keep lows in the lower 60s.

25

&&

.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 06z TAFs through 06z Saturday Night)
Issued at 1133 PM CDT Fri May 31 2024

Rain will push northeast across central IL overnight, with
ceilings gradually lowering to MVFR around sunrise. Guidance is in
better agreement that IFR ceilings will overspread the area from
the southwest during the morning, and persist through 06z,
possibly dropping to LIFR during the evening. Isolated to
scattered TSRA will be around Sat afternoon, and introduced a
PROB30 group for several hours. Winds to remain southeast through
the forecast at around 10 kt.

25

&&

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

$$