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000
FXUS63 KILX 220847
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
347 AM CDT Mon Apr 22 2024

.KEY MESSAGES...

- Rain chances return Monday night into Tuesday, with a 20% chance
  for an isolated storm.

- Brief cool down for midweek with frost/freeze potential possible
  near and north of I-74 Thursday morning. There is a 40-70%
  chance for air temperatures to fall below 36 degrees.

- A warmer and more active weather pattern arrives late in the
  week. Several chances for showers and storms exist late Thursday
  night through the weekend, including the potential for severe
  weather.

&&

.DISCUSSION...
Issued at 347 AM CDT Mon Apr 22 2024

A surface high is centered over the ArkLaTex region early this
morning with surface ridging extending as far north as the eastern
Great Lakes region. Gentle winds and clear skies under the high`s
presence have allowed temperatures to dip down into the 30s to
low 40s as of 3 am, with frost formation still a threat through
about sunrise. Winds are in the process of backing to the
southwest as a surface low works across the southern portions of
the Canadian Prairies, sending the surface high into the southeast
US later today. A cold front associated with the low will
approach from the west on Tuesday, sparking the development of
rain showers overnight. The pressure gradient will tighten ahead
of the front with wind gusts looking to approach 20-30 mph by this
afternoon. Forecast soundings show deep mixing up to ~800 mb by
this afternoon, which should mix down much warmer and drier air.
High temperatures today should be near or slightly above normal
(middle 60s), with dewpoints in the upper 20s to low 30s.


Precipitation later tonight could struggle to reach the ground
initially due to the drier airmass in place, so ended up slowing
down PoPs with likely chances (60% or higher) not expected until
closer to sunrise Tuesday when stronger forcing with the front
arrives. Thunderstorm chances look limited until Tuesday afternoon
when the right front entrance region of a mid-level jet becomes
centered over the middle Mississippi Valley. Despite this, limited
amounts of moisture will keep instability meager and keep severe
weather chances very low. Precipitation will end by Tuesday
evening as the cold front pushes out of the area. Precipitation
amounts look to be around 0.5 inch or less.

Surface high pressure settles in behind the frontal passage, leading
to a brief midweek cool down. Overnight lows Wednesday and Thursday
morning will be unseasonably cool, with the threat of frost or
freeze potential returning near/north of I-74 Thursday morning. The
NBM has a 40-70% chance for low temperatures to hit or fall below 36
degrees. The cool down will be short lived with temperatures
rebounding back above normal late in the week as upper ridging
amplifies over the eastern CONUS positioning southwest flow overhead.

The weather pattern will become more active late in the week and
weekend as a few systems and upper disturbances work through the
area. The first will be on Friday when a surface low lifting into
the Northern Plains sends a warm front north through the area.
Showers and storms will accompany the front early Friday morning as
it quickly lifts north into the Great Lakes Region. Later in the
day, a cold front will approach from the west, but looks to stall
out before reaching the area. Because of this, instability Friday
evening will be highest just west of the area, which is where storms
should initiate. Strong wind shear and steepening lapse rates with
an approaching negatively tilted upper wave could lead to a few
strong to severe storms, with activity spreading into our CWA later
that evening.

The cold front will become mostly stationary somewhere over the
Midwest states on Saturday and Sunday with variability on where
exactly it will be. Further west, another strong Pacific trough will
eject northward and spin up a surface low over the Plains states
late Saturday night into Sunday. A few upper shortwaves will pivot
northward along the aforementioned stationary boundary this
weekend, bringing periods of showers and storms through the
weekend before the main wave arrives sometime Sunday into Monday.
Severe weather chances area a possibility through the weekend,
though details remain fuzzy due to timing differences.

NMA

&&

.AVIATION...  (For the 06z TAFs through 06z Monday Night)
Issued at 1147 PM CDT Sun Apr 21 2024

VFR conditions will prevail through the entire 06z TAF period.
Winds will initially be SW at less than 10kt, then will increase
and gust over 20kt from midday Monday through Monday night. Skies
will be clear through midday, followed by increasing high clouds
during the afternoon. After that, forecast soundings suggest
cloud bases will lower to around 12,000ft by evening.

Barnes

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 8 AM CDT this morning for ILZ027>031-
036>038-040>057-061>063-066>068-071>073.

&&

$$