651
FXUS63 KILX 160431
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1131 PM CDT Sat Jun 15 2024

.KEY MESSAGES...

- Seasonably hot and humid weather is on tap for next week. Heat
  index values will peak at or above 100 degrees from Sunday
  afternoon through Monday afternoon before readings settle back
  into the middle to upper 90s for the remainder of the week.

&&

.UPDATE...
Issued at 743 PM CDT Sat Jun 15 2024

Thicker high clouds have been moving past the I-74 corridor and
will be out of the area soon. However, skies generally remain
partly cloudy west of I-55 overnight, ahead of a shortwave
currently across eastern parts of South Dakota and Nebraska.
A couple small MCS`s are ongoing in this area and will lift
northeast overnight. Latest HRRR runs have been suggesting a
glancing blow early Sunday morning northwest of the Illinois
River, though general CAM solutions have been tracking it more
into northwest Illinois. Went ahead and added some 20% PoP`s early
morning north of a Galesburg-Pontiac line to address this
possibility. Otherwise, only minor edits made to the forecast
grids at this time.

Geelhart

&&

.SHORT TERM...(Tonight through Sunday Night)
Issued at 228 PM CDT Sat Jun 15 2024

A 1025mb high centered over southern Ontario continues to dominate
the weather across central Illinois this afternoon. 19z/2pm
temperatures are in the middle to upper 80s: however, dewpoints
have diurnally mixed into the lower to middle 50s...resulting in
comfortable conditions. Plenty of high cloudiness from a pair of
short-wave troughs over the Plains is drifting eastward, leading
to a high/thin overcast everywhere north of I-70. These clouds
will persist through the night as the wave currently over western
Kansas lifts northeastward toward the Great Lakes. CAMs keep any
associated convection along/west of the Mississippi River late
tonight into early Sunday morning, but will still need to keep an
eye out for an isolated shower along/north of a Rushville to
Bloomington line. Lows tonight will range from the lower 60s near
the Indiana border to the upper 60s to around 70 degrees in the
Illinois River Valley where cloud cover will be more prevalent. As
the wave lifts into the Great Lakes, boundary layer winds will
veer to the SW and increase behind a departing warm front. This
will bring hotter and more humid air into the region, pushing
afternoon highs into the lower to middle 90s. Thanks to dewpoints
climbing well into the 60s to around 70 degrees, Sunday afternoon
heat index values will peak around 100 degrees.

Barnes

.LONG TERM...(Monday through Next Saturday)
Issued at 228 PM CDT Sat Jun 15 2024

The hottest day of the forecast period will be Monday when air
temperatures reach the middle 90s and heat index values climb into
the 100-105 degree range. The one mitigating factor for the heat will
be southwesterly winds gusting 20-25mph. As has been seen by the
past several model runs, increasing deep-layer moist advection
from the western Gulf of Mexico will lead to an increase in cloud
cover and the development of widely scattered convection Monday
afternoon. The same scenario will unfold on Tuesday, with the
increase in cloud cover leading to less hot high temperatures in
the upper 80s and lower 90s and heat index readings below 100
degrees.

After that, seasonably hot and humid summer-like weather will
prevail for the remainder of the extended...with periodic very
low chance PoPs. It does not appear any significant frontal
boundaries will push into the region, so any convection that
occurs will remain widely scattered and disorganized Wednesday
through Saturday.

Barnes

&&

.AVIATION...  (For the 06z TAFs through 06z Sunday Night)
Issued at 1131 PM CDT Sat Jun 15 2024

Showers/storms west of the Mississippi River are expected to
largely track northwest of KPIA early Sunday morning, but may be
close enough to produce some brief ceilings around 5,000 feet
there. Overall, VFR conditions will be the rule the next 24
hours. Winds turn southerly and increase to 10-15 knots early
Sunday morning, and a few gusts near 20 knots or so can`t be ruled
out. Winds should drop off around sunset.

Geelhart

&&

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

$$