Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 081953

Area Forecast Discussion
National Weather Service Lincoln IL
253 PM CDT Sat Aug 8 2020

Issued at 253 PM CDT Sat Aug 8 2020

An area of thunderstorms will develop over west central Illinois
this evening and track southeast into early Sunday morning. The
best rain chances will be west of Springfield and Effingham, with
many areas northeast near I-74 remaining dry into much of Sunday.
Another round of showers and thunderstorms should move into the
region from the northwest Sunday evening.


.SHORT TERM...(This evening through Sunday)
ISSUED AT 253 PM CDT Sat Aug 8 2020

MCV has steadily tracked across Missouri today and was seen on
radar north-northwest of St. Louis at 2 pm. Morning high-res
models are in decent agreement with development of a convective
cluster in that general vicinity this evening, as it interacts
with a warm front over the area, though the finer details have
some variation. General thought is for the heavy rain focus to
remain near the Illinois/Missouri border, so will hold off on any
flood watches at this point. However, likely PoP`s were introduced
for areas from Rushville southeast to Flora centered around the
sunrise period. Will keep areas near and north of I-74 dry for the
most part, though a couple stray storms will be possible this
evening from about Peoria south.

With the more extensive clouds sticking around much of the day
over the eastern CWA, high temperatures have been lowered about 5
degrees on Sunday in that area. Further west, afternoon sunshine
behind the MCS should help boost temperatures to the upper 80s
across the Illinois River Valley, with heat index readings close
to 100.


.LONG TERM...(Sunday night through Saturday)
ISSUED AT 253 PM CDT Sat Aug 8 2020

Not a lot of change in the general forecast thinking through mid
week, as the challenge will be with timing of additional nocturnal
MCS`s rolling along the top of the upper level high across the
southern Rockies. As we get later in the week, some discrepancies
develop with the longer range models. This morning`s European
model run closes off an upper low near the Illinois/Iowa border by
midday Friday, which is further west and about 24-30 hours
earlier than last night`s run. It keeps it in Illinois much of the
upcoming weekend, which would be a much cooler and wetter
solution than what is currently in the blended forecast. The GFS
is weaker and more progressive with this feature. Plenty of time
for that to shake out at such a long range.

Warmest conditions expected on Monday, with highs near 90 and heat
index around 100 in most areas.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1210 PM CDT Sat Aug 8 2020

VFR conditions expected to prevail through the period. Main
concern would be with a lowering ceiling/visibility associated
with expected development of a thunderstorm cluster across west
central Illinois this evening. Current track would keep most of
the storms just southwest of KSPI, but close enough to warrant a
close eye and a concern for lower ceilings by 12Z. Ahead of that,
a few thunderstorms are also possible there late this afternoon
through about sunset, and a VCTS mention will be included in the
new TAF set for that period.




SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...Geelhart is the U.S. government's official web portal to all federal, state and local government web resources and services.