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Area forecast discussion
National Weather Service Lincoln Illinois
915 PM CDT Sat Aug 24 2019

issued at 340 PM CDT Sat Aug 24 2019

Fair weather will continue over much of central and southeast Illinois
tonight, with seasonably cool lows in the mid to upper 50s.
An approaching upper level system into the mid Mississippi River
valley on Sunday and Sunday night will start to bring some
showers and isolated thunderstorms back into the area especially
over east central and southeast Illinois by later Sunday afternoon into
Sunday night. Mostly cloudy skies are expected on Sunday with
highs of 75 to 80 degrees. Showers and some thunderstorms will
remain possible Monday through Tuesday, with the best chances
during Monday night as a cold front passes through the area.


issued at 915 PM CDT Sat Aug 24 2019

Thin high clouds is all that is seen on satellite photos and
nothing on radar this evening. So, current going forecast still
looks good for rest of the night with temps dropping into the mid
to upper 50s again tonight with light easterly winds. Therefore no
update planned at this time.


Short term...(this evening through sunday)
issued at 340 PM CDT Sat Aug 24 2019

1027 mb Canadian high pressure over the northeast Great Lakes will
drift east into New England on Sunday. Scattered diurnally driven
cumulus clouds with bases around 5k ft over central Illinois this
afternoon should diminish as sunset. Fair and seasonably cool
weather will continue tonight over much of the area as mid/high
clouds increase from the SW overnight with lows in the mid to
upper 50s. Coolest lows overnight in NE County Warning Area where less cloud cover

Latest models continue to show an upper level trof moving east
into Iowa/MO/AR by late Sunday afternoon, and increasing warm air advection ahead
of this trof into Illinois during the day Sunday. Models have continued
quicker with spreading chances of showers into County Warning Area on Sunday and
Sunday night. Have 20-30% chance of showers from Springfield to
Terre Haute south on Sunday, with isolated thunderstorms possible
south of I-70 late Sunday afternoon. Mostly cloudy skies Sunday
keeps temps a bit cooler with highs 75-80f, coolest in SW County Warning Area
where more clouds expected thru the day Sunday.

Long term...(sunday night through saturday)
issued at 340 PM CDT Sat Aug 24 2019

The upper level trof/disturbance slowly moves east over the MS
River Valley by overnight Sunday night and increase chances of
showers and isolated thunderstorms over central/se Illinois with highest
pops east of I-55 by overnight Sunday night into Mon morning. Not
as cool Sunday night due to clouds and waa with lows in the lower
60s northern cwa, mid 60s central sections and upper 60s in
southeast Illinois.

The upper level trof/short wave tracks into the lower Ohio/Tennessee River
valley Monday afternoon and should see convection chances
gradually diminish in eastern/se Illinois Mon afternoon. Pops mainly in
the 20-40% range on Mon afternoon, though higher pops early Mon
afternoon along the in border. Highs Mon in the lower 80s and
more humid dewpoints in upper 60s/lower 70s with southerly flow.
So a taste of Summer returning to the area on Monday.

A fairly strong northern stream short wave/trof near the Canadian
West Coast to dig into the Midwest and drive a cold front se thru
County Warning Area during Mon night, likely bringing a band of showers and some
thunderstorms. Storm Prediction Center day3 outlook as marginal risk of severe storms
far NW County Warning Area and wpc day3 outlook also has marginal risk of
excessive rainfall NW of the Illinois River for Mon night especially Mon
evening as precipitable water values reach around 2 inches for a
time ahead of cold front.

Chances of showers and a few thunderstorms lingers in eastern/se
Illinois on Tue and diminishing during Tue afternoon as front pushes
away from the area. Decreasing clouds during Tue from NW to se
with a fair amount of sunshine developing during Tue afternoon
with highs around 80f to lower 80s with drier air ushering in
by Tue afternoon.

Dry weather returns to area Tue night into Wed night as weak high
pressure settles into the MO and mid MS River Valley. A bit cooler
highs of 75-80f on Wed with upper level trof over the Great Lakes
and into Illinois and Ohio River valley, warmest by Lawrenceville.
Stayed close to consensus of models from Thu thru Saturday with
most of this time frame being dry with below normal temps, highs
staying in the mid to upper 70s Thursday thru Saturday. A frontal
boundary pushing se thru Illinois overnight Thu night into Friday does
not have much moisture to work with but could give slight chances
of showers around that time.


Aviation...(for the 00z tafs through 00z Sunday evening)
issued at 625 PM CDT Sat Aug 24 2019

VFR conditions will prevail at all taf sites next 24hrs. As cumulus
dissipates, high cirrus is all the tafs will see this evening and
overnight. The cirrus will become broken during early morning
hours and then more cumulus is expected to develop around 5kft tomorrow
mid morning and then continue into the afternoon. At same time,
expecting some broken ac around 8-9kft to develop and continue
into the afternoon. Any precip is expected to hold off til later
tomorrow. Winds will be easterly through the period with speeds of


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