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FXUS63 KILX 211703
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1203 PM CDT Fri Jun 21 2024

.KEY MESSAGES...

- The recent stretch of hot weather will continue through Saturday
  as afternoon heat index readings peak in the upper 90s to
  around 100 degrees.

- A cold front will bring a chance for thunderstorms to parts of
  central Illinois Saturday evening into Saturday night. A few of
  the storms could become strong to severe...particularly along
  and west of the I-55 corridor.

&&

.SHORT TERM...(Today through Saturday)
Issued at 344 AM CDT Fri Jun 21 2024

As upper ridging remains firmly in place across the Midwest/Ohio
River Valley, hot and humid conditions will persist through
Saturday. Any substantial convection will remain well N/NW of
central Illinois as high temperatures climb into the middle 90s
both days. Peak afternoon heat index readings will reach the upper
90s to around 100 degrees.

A short-wave trough tracking through the Northern Plains into the
Great Lakes will flatten the upper ridge and push a cold front
toward central Illinois by late Saturday. 00z Jun 21 CAMs have
slightly varying solutions concerning the exact speed of the
front: however, overall consensus suggests it will get close
enough to warrant low chance PoPs along/northwest of the Illinois
River by late Saturday afternoon. The airmass ahead of the front
will become moderately unstable...with HREF ensemble mean SBCAPEs
peaking at 2000-2500J/kg across eastern/southern Iowa into
northern Missouri after 21z Sat. As 0-6km bulk shear increases to
30-35kt ahead of the approaching short-wave, clusters of
thunderstorms will develop along/ahead of the boundary with an
attendant risk for large hail/damaging wind gusts. These cells
will develop and/or spread southeastward into the NW KILX CWA
toward sunset...then to near I-72 shortly before midnight. As
daytime instability wanes, the risk for severe weather will
rapidly diminish and areal coverage of convection will decrease
further southeast overnight. At this time, it appears the highest
probability for scattered hail and damaging wind gusts will be
focused along/west of the I-55 corridor late Saturday afternoon
and evening. Rainfall associated with the front will be greatest
across the N/NW CWA...with decreasing amounts further southeast.
12z Jun 20 LREF indicates a high probability (greater than 50%
chance) of 0.50 of rain or more along/north of a Macomb to Peoria
line. Those probabilities drop to 20% or less along I-72 and less
than 10% along/south of I-70. As a result, do not think the storms
Saturday evening will do much to alleviate the developing drought
conditions across much of central and southeast Illinois.

Barnes

.LONG TERM...(Sunday through Thursday)
Issued at 344 AM CDT Fri Jun 21 2024

The cold front will settle southward to the Ohio River by Sunday
afternoon. Have continued chance PoPs along/southeast of a
Danville to Shelbyville line as the front passes...but am not
expecting any substantial or widespread rainfall on Sunday. The
main story will be the slightly cooler/less humid conditions as
highs drop into the upper 80s to around 90 degrees.

After a warm/dry day on Monday, another cold front will drop into
the region by Tuesday. Temperatures will spike back into the
middle 90s ahead of the boundary, potentially setting the stage
for another round of scattered strong convection during the
afternoon and evening. Once the second front passes, upper
troughing over the Great Lakes will bring a more substantial
cool-down for the end of next week as highs drop into the middle
to upper 80s by Wednesday/Thursday.

Barnes

&&

.AVIATION...  
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(For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1157 AM CDT Fri Jun 21 2024

A damping ridge aloft will help keep terminals at VFR through this
TAF period. High clouds will increase later this evening into
Saturday as a slow- moving cold front approaches from the
northwest. Low- level winds will remain from the south through
this evening, becoming southwest and increasing late Tuesday
morning ahead of the front.

MJA
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&&

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

$$