878
FXUS63 KILX 070513
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1213 AM CDT Mon Jul 7 2025

.KEY MESSAGES...

- Seasonably hot and humid conditions are expected the next
  several days, with highs mainly from the mid 80s to around 90,
  and heat index peaking around 90 to 95 daily.

- Occasional periods of scattered showers and thunderstorms can be
  expected for the upcoming work week.

&&

.DISCUSSION...
Issued at 222 PM CDT Sun Jul 6 2025

Lift associated with an upper level shortwave trough and a cold
front draped northeast to southwest across central IL have
prompted the initiation of scattered showers and thunderstorms
this afternoon, which should continue into this evening before
diminishing over the area overnight as the front pushes to the
south and the shortwave moves to the east. With MLCAPE values of
2000-3000 J/kg but weak shear, a few strong storms containing
strong wind gusts could take place, and a SPC has designated a
Marginal Risk for severe storms. HREF ensembles continue to
advertise very isolated 2-3 inch rainfall accumulations through
this evening due to slow storm motion and precipitable water near
2 inches. Isolated instances of flash flooding will need to be
watched for, especially if occurring in urban or poor drainage
areas.

With the front lingering just south of the I-70 corridor Monday, we
could see another round of showers and thunderstorms near and south
of I-70, then a break should take place Monday night as surface high
pressure drifts by to the north, ridging into central IL.

A few upper level waves in a weak zonal/westerly flow pattern look
to bring chances for more showers and thunderstorms midweek through
next weekend. Although timing is far from certain at this point, the
first of these looks to work its way slowly across the area late
Tuesday through Wednesday, followed by a couple more late week
into the weekend. PoPs Wednesday through the weekend depict
somewhat of a diurnal trend with highest values during the
afternoon to early evening, generally 30 to 50 percent. Severe
weather chances look to be generally low, although a few model
runs depict a potent enough shortwave for severe weather around
Friday.

Temperatures look to run seasonably hot and humid for the upcoming
week, with highs ranging from mid 80s to around 90, lows from mid
60s to lower 70s, and dewpoints from the 60s to lower 70s, resulting
in heat index values peaking around 90 to 95 daily.

37

&&

.AVIATION...  (For the 06z TAFs through 06z Monday Night)
Issued at 1213 AM CDT Mon Jul 7 2025

Cloud deck near 1000 feet has been edging southwest into central
Illinois, as winds shift to the northeast behind surface boundary.
Ensemble guidance shows the lowest ceilings mainly impacting KCMI,
and perhaps KDEC/KBMI at times. However, a tongue of low clouds in
the guidance extends as far west as KSPI, and ceilings nearby are
at 1600 feet, so this seems plausible. Conditions at KSPI/KDEC are
expected to improve by 12Z as the cloud tongue pushes southward,
though it may take a few more hours to fully clear out in eastern
Illinois. By late morning, a clearing trend will be taking place
from west to east, with VFR conditions prevailing the remainder of
the forecast period.

Geelhart

&&

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

$$