000
FXUS63 KILX 250946
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
446 AM CDT Thu Apr 25 2024

.KEY MESSAGES...

- Waves of showers and storms will be seen Friday through Sunday.
  Storms could be severe at times and also bring heavy rainfall.

- Temperatures will climb to near 80 this weekend, with extended
  outlooks favoring warmer than normal conditions continuing
  through next weekend.

&&

.DISCUSSION...
Issued at 335 AM CDT Thu Apr 25 2024

Light east winds under surface ridging and mostly clear skies has
allowed temperatures to drop into the 30s early this morning. Cirrus
tied to an upper shortwave diving south through Minnesota will
spread into the area today, but otherwise dry and somewhat cooler
than normal conditions will prevail.

A more active weather pattern is in the works for later this week
into the weekend as a pair of low pressure systems lift through the
Plains states and Midwest. The first will be Friday into Saturday
with the second Saturday night into Sunday night. The aforementioned
upper ridge will shift into the eastern US and amplify, leaving
southwest flow positioned overhead here locally. Temperatures will
quickly warm through the weekend, approaching 80 degrees by
Saturday. A wide open Gulf will advect higher dewpoints northward
through the weekend, approaching 60 on Friday and middle 60s
Saturday.

A warm front will lift north through the area on Friday, with strong
WAA sparking the develop of showers and storms Friday morning.
Limited instability with the morning activity should keep the
severe threat minimal. The surface low will enter Nebraska Friday
evening as the negatively tilted upper wave catches up to it. As
the LLJ ramps up Friday evening, convection will blossom along and
ahead of a dryline boundary/front near the Kansas/Missouri border
where the better instability will be. The LLJ and instability
gradient will gradually spill into Illinois late Friday night,
allowing storm activity to continue as it approaches. A few severe
storms could occur during this time.

Morning shower and storm activity could linger into Saturday morning
as the surface low enters the Upper Mississippi Valley. A
stationary front will stretch south of there into the central
Plains with the second surface low spinning up near the Oklahoma
panhandle. This second system will take a similar track as the
first, but just a bit further east. The latest guidance shows us
quickly destabilizing by the afternoon hours with a 50-70% chance
for SBCAPE > 1000 J/kg west of I-55 and similar probabilities for
bulk shear > 30 kts in that same area. Lack of forcing will likely
keep most of the storm activity west of here throughout the day
until the low pushes the stationary/cold front into western parts
of our area later Saturday night. The threat for severe storms
also exists Saturday night, but another concern is the threat for
heavy rainfall due to training of storms through Sunday morning.

The cold front will track slowly through the area Sunday into Sunday
night, bringing yet another day of potential storm activity. Forcing
will be the strongest on Sunday with the front in the vicinity, but
lingering convection from the night prior could prevent us from
fully destabilizing. Total precipitation through the weekend
looks to range from 1 to 2 inches, though areas west of I-55 could
see amounts higher than that.

Temperatures stay mild through the new week with the Climate
Prediction Center showing above normal temperatures sticking
around through at least next weekend.

NMA

&&

.AVIATION...  (For the 12z TAFs through 12z Friday Morning)
Issued at 446 AM CDT Thu Apr 25 2024

VFR conditions continue through the TAF duration. East winds veer to
the southeast later this morning with speeds sitting around 10 kts.
Shower and storm chances return after 12Z Friday when a warm
front lifts through the area, bringing the next change in flight
conditions.

NMA

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 6 AM CDT early this morning for ILZ030-031-
038-043>046.

&&

$$