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FXUS63 KILX 110108
AFDILX

Area Forecast Discussion...Updated
National Weather Service Lincoln IL
808 PM CDT Thu Jul 10 2025

.KEY MESSAGES...

- Daily chances for afternoon/evening thunderstorms will be seen
  through the weekend with the highest chances being on Friday
  and Saturday.

- Hot and humid conditions will be in place through the end of
  this week and again early next week. Temperatures look to trend
  cooler by the end of next week.

&&

.UPDATE...
Issued at 808 PM CDT Thu Jul 10 2025

Decreased thunderstorm chances this evening to slight chance for
most of the evening with dramatic weakening of convection that
moved from southeast IA into west central IL. Nevertheless, the
low level jet developing farther west in northern MO/southern IA
has been enhancing more thunderstorm activity in that area, and
this should extend east-northeastward into northern IL late this
evening and after midnight. How much of central IL is affected
remains in question, as a few models depict activity remaining
north of Knox, Stark, and Marshall Counties, while a few bring
activity through that area and even a county or two to the south.
Current slight chance to chance category PoPs in this area appear
to be on target, so have left forecast as-is after midnight.
Otherwise, lows near 70 appear on track for tonight.

37

&&

.DISCUSSION...
Issued at 251 PM CDT Thu Jul 10 2025

...Daily Storm Chances Through the Weekend...

A few widely scattered showers and storms have developed in east-
central Illinois along a remnant outflow boundary from an overnight
thunderstorm complex. Further northwest, a MCV from the same storm
complex is spinning over southeast Minnesota/northeast Iowa and
will be the focus for thunderstorm development over the northern
half of Illinois going into this evening. Although most guidance
keeps the majority of this activity north of our local area, a few
outlier solutions do show storms stretching as far south as I-72.
Increasing shear with the approaching MCV and moderately strong
instability could lead to a few organized storms capable of mainly
strong winds and heavy rainfall.

A low-level jet will nose into northern IL overnight, leading to
repeated rounds of heavy rainfall north of the area. Better
chances for precipitation arrive later on Friday here locally as a
shortwave impulse ahead of a parent trough spreads into the
middle Mississippi Valley Friday afternoon. A warm front is
expected to lift into north- central parts of the state by evening
with hot and humid conditions developing south of the front.
Instability will become moderately strong by afternoon with
SBCAPEs looking to approach or exceed 2000 J/kg. ~30 kt of
effective wind shear, especially near the front, will be
sufficient for thunderstorm organization, posing a risk for all
severe hazards. Storms look to fire up sometime late Friday
afternoon or early evening in our west, with activity spreading
east into the nighttime hours.

A cold front moving through the area on Saturday will bring
additional chances for precipitation through the weekend. The better
upper forcing will be displaced north of the area, though hot and
humid conditions and increasing wind shear with the front will once
again lead to marginal parameters for a few stronger thunderstorms
Saturday afternoon and evening.

Predictability becomes less certain going into next week, though a
brief break in precipitation appears possible early in the week as
an upper ridge moves overhead. Upper troughing looks to swing back
through the northern CONUS by midweek, which could lead to
additional precipitation chances later in the week.

...Hot and Humid Through the End of the Week, Again Early Next Week..

Despite daily precipitation chances, temperatures will remain hot
and humid through the end of this week with high temperatures on
Friday peaking in the low to middle 90s paired with heat indices
around 100, give or take a few degrees. Temperatures fall slightly
over the weekend with the cold front passage, but will quickly
rebound by the beginning of next week as an upper ridge slides
through the Midwest states.

Temperatures by the end of next week into next weekend look to trend
somewhat cooler than normal with the Climate Prediction Center`s 8-
14 day temperature outlook (Jul 17-23) highlighting a 33-50% chance
for below normal temperatures.

NMA

&&

.AVIATION...  (For the 00z TAFs through 00z Friday Evening)
Issued at 625 PM CDT Thu Jul 10 2025

A cluster of thunderstorms looks to slowly move toward the central
IL terminals while weakening this evening. At this point,
probability of thunderstorms affecting terminals southeast of KPIA
appears too low for inclusion in TAFs, and likely to be several
hours away, so have only included PROB30 mention of thunder at
KPIA from 02Z-05Z. Additional storms will likely develop in the
vicinity of southeast IA to northern IL Friday afternoon, and
sweep eastward. At this point, probability for these storms
affecting terminals southeast of KPIA looks too low for mention
prior to 00Z, but have included PROB30 for TSRA at KPIA from
21Z-24Z. Winds SSW 6-10 kts through Friday morning, increasing to
10-12 kts with gusts near 20 kts by 16Z.

37

&&

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

$$