076
FXUS63 KLSX 080658
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
158 AM CDT Wed Oct 8 2025

.KEY MESSAGES...

-Near normal temperatures will continue into Thursday before warming
back above normal over the weekend and into next week.

-Dry conditions are favored through the end of the week.


&&

.SHORT TERM...  (Through Late Wednesday Afternoon)
Issued at 157 AM CDT Wed Oct 8 2025

Morning satellite imagery shows the region caught in between a mid-
level trough over the Great Lakes region and a weak ridge over the
Southern Plains. The axis of the trough has exited the region, and
at the surface yesterday`s cold front is now south of the forecast
area. In its wake relatively cooler, dry air has moved into the
region with a surface high. While the new airmass is cooler than
we`ve experienced lately, temperatures will peak near normal for
this time of year with highs in the low 70s areawide under a clear
sky.

The surface high will stick around, and radiational cooling and
light winds overnight will allow temperatures to cool well below
normal across the area. Temperatures will reach their minimums in
the 40s, with some localized areas in the hollows and across west-
central Illinois closest to the high reaching into the upper 30s.
The mid-level ridge strengthens over the Central Plains Thursday,
leaving the mid-Mississippi Valley within northwesterly mid-level
flow. The surface pattern will remain unchanged, and after a chilly
start, temperatures will be similar to Wednesday with highs in the
low 70s.

Delia

&&

.LONG TERM...  (Wednesday Night through Monday)
Issued at 157 AM CDT Wed Oct 8 2025

The mid-level ridge will continue to strengthen Friday, while a mid-
level cut off low will move southeast into the Great Lakes region.
At the surface a low will quickly develop over the Great Lakes
region in response, but the system will quickly occlude and the
associated surface fronts are expected to stay to the north of the
forecast area. Instead, southwesterly low-level flow across the mid-
Mississippi Valley will kick off a warming trend that will last
through the end of the forecast period.

The southwesterly flow will deepen as the axis of the mid-level
trough shifts east over the weekend, and will last through next
week. This will open the region back up to shortwaves, though
confidence in moisture return and the timing of any one disturbance
is low at the moment. However, confidence is high that temperatures
will warm above normal over the weekend and into next week as the
interquartile range has continued to narrow over the past several
days. Now the range is only 6-8 degrees heading into next week, with
the 25th percentile above normal for this time of year.

Delia

&&

.AVIATION...  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1143 PM CDT Tue Oct 7 2025

Under clear sky and light northerly winds most TAF sites are at
VFR flight conditions. The exception is KSUS, where fog has
developed and is bouncing the site between IFR and MVFR conditions.
Dry air is moving into the region and will erode the fog, though
its uncertain how fast this will occur. The best timing for VFR
conditions to return to the site is around 07Z given observations
at nearby sites, which is reflected in the TAF.

Delia

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

$$

WFO LSX