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000
FXUS63 KILX 231554
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1054 AM CDT Fri Apr 23 2021

.SYNOPSIS...
Issued at 330 AM CDT Fri Apr 23 2021

Mostly cloudy skies will prevail today over Illinois along with
some light rain showers from I-55 west. More widespread rain
showers will overspread central and southeast IL during tonight,
with wet weather likely continuing into Saturday. The rain should
end over the IL river valley Saturday afternoon, and over the
rest of the area by Saturday evening. Seasonably cool temperatures
will prevail into this weekend. Highs of 55 to 60 degrees today,
upper 50s to lower 60s Saturday, and in the low to mid 60s Sunday.
Much warmer conditions are expected Monday and Tuesday, with
highs in the mid 70s to lower 80s.

&&

.UPDATE...
Issued at 1001 AM CDT Fri Apr 23 2021

Clouds will continue to increase in coverage this afternoon as
synoptic-scale ascent becomes enhanced ahead of an upper-level
trough lifting into the Southern Plains. Meanwhile, low-level dry
air observed by the 12z ILX sounding will mitigate the chance for
widespread showers this afternoon. The better chance will arrive
later this evening once the lower troposphere saturates. Most
locations will receieve 0.25" of rainfall or less through Saturday,
but some locations may receive up to 0.75" wherever the
frontogenetic forcing/banding precip develops. The rain is on
track to exit the region from west to east by Saturday evening.

Temperatures will warm near 60 degrees this afternoon as low-
level return flow on the western periphery of a departing surface
high helps advect a modified Gulf air mass northward into central
Illinois.

&&

.SHORT TERM...(Today and tonight)
ISSUED AT 330 AM CDT Fri Apr 23 2021

Early morning surface map showed 1023 mb high pressure over
western NC/VA into southern WV and ridging westward into the mid
MS river valley including southeast IL. A 1004 mb low pressure was
along the southern CO/KS border with a warm front extending thru
sw OK into ne Texas and near the AR/LA border. Aloft the water
vapor loop shows a northern stream short wave trof over the
eastern Dakotas while a southern stream trof was over AZ into nw
Mexico. Broken to overcast mid level clouds had overspread much of
IL during the night while rain showers were south of I-64 over
southern IL into central/se parts of MO and tracking eastward.
Temps were in the upper 30s to mid 40s over CWA, mildest from
Springfield sw. CMI airport was down to 34 from midnight to 1 am
until mid level clouds spread in during early overnight and now
up to 38F.

Latest CAMs have trended slower with arrival of light rain showers
from the west during today with weak lift and limited low level
moisture. Have lower pops today especially in eastern IL where we
have nudged highs up a few degrees. Highs in the mid to upper 50s
today, expect upper 50s to near 60 degrees in eastern IL where
more peaks of sunshine expected as mid level clouds thin for a
time during midday/early afternoon. Winds become breezy SSW today.

Best forcing pushes east into IL during tonight as short wave trof
approaches IL, with better chance of rain showers, though not
getting into southeast IL until late evening or overnight. Very
limited instability over CWA thru tonight and have removed the
isolated thunderstorms this afternoon and tonight over southern/sw
CWA. A little more support for a few thunderstorms in southern/sw
IL late this afternoon into tonight. Lows tonight in the mid to
upper 40s.

.LONG TERM...(Saturday through Thursday)
ISSUED AT 330 AM CDT Fri Apr 23 2021

The short wave trof pushes east into IL Sat morning and exits east
of IL during Sat afternoon. Continued high chances of rain showers
Sat morning especially east of the IL river, then diminish pops
from the west during Sat afternoon with the IL river valley dry by
Sat afternoon with cloudy skies becoming partly sunny. Brunt of
rain showers shift east of IL by sunset Sat. Rainfall amounts
between a half and three quarter inches expected over much of the
area by sunset Saturday, though lighter amounts by Galesburg where
quarter to half inch amounts expected. Highs Sat in the upper 50s
and lower 60s, mildest over the IL river valley where more
sunshine expected later in the day.

Weak 1020 mb high pressure ridge settles over IL/WI by midday
Sunday and bringing a nicer spring day to the area with mostly
sunny skies and lighter winds. Highs Sunday in the low to mid
60s, mildest over southern/SW CWA. Models show some qpf over the
upper MS river valley and possibly as far south as nw IL Sunday
afternoon with some increasing clouds over central IL.

Strong south winds on back side of high pressure ridge on Monday
over IL with gusts 25-35 mph and possibly higher along with a
fair amount of sunshine, to bring a nice warm up, with highs in
the mid to upper 70s. Highs around 80 to lower 80s on Tuesday with
isolated showers/thunderstorms over the IL river valley Tue
afternoon. A deep upper level trof into the southern Rockies Tue
and into the southern Plains Wed to bring a stronger storm system
into IL during midweek. Showers and thunderstorms likely spread
east over the area during Tue night into Wed. Low pressure
ejecting ne into central IL and then into lower MI Thu to continue
high chances of showers and some thunderstorms. Moderate to heavy
rains possible from Tue night thru Thu and during that period
could also be a risk of stronger thunderstorms. Highs Wed in the
low to mid 70s, warmest in southeast IL. Highs Thu range from
lower 60s over the IL river valley and around 70 along the Wabash
river.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 555 AM CDT Fri Apr 23 2021

VFR conditions are expected to continue through about sunset
across the central IL airports with some sprinkles possible.
Broken mid level clouds around 10k ft early this morning to lower
to 4-6k ft this afternoon. MVFR ceilings accompanied by some rain
showers will spread east over central IL during early evening
with IFR to low end MVFR ceilings setting in during overnight
with MVFR vsbys from more widespread rain showers. SSW winds to
increase to 10-14 kts with gusts around 20 kts by late morning and
afternoon. Winds to veer SE this evening and diminish to 5-10
kts.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...MJA
SYNOPSIS...07
SHORT TERM...07
LONG TERM...07
AVIATION...07