260
FXUS63 KLSX 231125
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
625 AM CDT Fri Oct 23 2026

.KEY MESSAGES...

- High pressure remains in place allowing for our dry and warm
  weather continues well into next week.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 347 AM CDT Fri Oct 23 2026

A slow moving upper-level ridge continues to dominate over the
central CONUS bringing dry and seasonably warm conditions to the Mid-
Mississippi Valley. Seasonably warm high temperatures are being
primarily driven by the ridge continuing its residence over the
region. High temperatures today and through the weekend will remain
in the mid to upper 70s, possibly reaching 80s in some areas. The
over night low temperatures on the other hand will remain more
seasonal. The dry air mass that remains in the region associated
with the surface high has allowed for efficient radiative cooling
through the region creating low temperatures into the upper 40s and
low 50s. Low temperatures overnight are expected to continue to be
in the upper 40s to low 50s through the weekend. The 40s will
primarily be located in the river valleys and in southeastern MO and
southwestern IL, where fewer clouds will allow for more radiative
cooling.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Issued at 347 AM CDT Fri Oct 23 2026

Over the western CONUS, a deep upper-level trough propagates to the
northeast toward the central CONUS early next week. Guidance
indicates that as this trough slowly moves to the northeast, its
amplitude will decrease enough to the point where the cold front
associated with the trough will stay well to the north of our
forecast region Tuesday into Wednesday, and allow for a ridge to
remain over the region. This will allow for continued dry and
seasonably warm conditions to continue through this forecast period
with high temperatures remaining in the 70s each day. Another trough
and associated cold front then begin to build over the western CONUS
before moving to the east toward the end of the week. Guidance is
uncertain on the exact timing and magnitude of this cold front in
Missouri. NBM guidance from yesterday had IQRs of 15-20 degrees on
Thursday and Friday with the 25th percentiles in the lower to mid-
60s and 75th percentiles near 80, but the most recent runs have
brought the IQRs closer to 10-15 degrees with 25th percentiles
brought up into the 70s on Thursday and mid to upper 60s on Friday
while keeping the 75th percentiles near 80. This hints that model
guidance is either pushing the cold front further into the future or
decreasing the magnitude of the front. Latest ensemble guidance has
increased the chances of rain associated with moisture ahead of the
front with a 20-50 percent chance of measurable rain by Friday
evening across the region.

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 625 AM CDT Fri Oct 23 2026

High pressure remains in place over the region allowing for light
winds and continued VFR conditions. There is a chance of fog at SUS
and CPS early this morning due to the light to calm winds, but will
be very spotty. SUS has already experienced a few observations of
IFR visibilities, but have been short lived.

&&

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

&&

$$

SHORT TERM...Asel/Kimble
LONG TERM...Asel/Kimble
AVIATION...Asel/Gosselin