289
FXUS63 KLSX 240729
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
229 AM CDT Sat Oct 24 2026

.KEY MESSAGES...
- A stagnant pattern remains in place keeping warm and dry
  conditions through the end of the week.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 228 AM CDT Sat Oct 24 2026

A slow moving upper-level ridge remains over the central CONUS
keeping dry and seasonably warm conditions in the Mid-Mississippi
Valley through the weekend and into Monday. As a result, very little
change in the weather day-to-day is expected. The only change is the
presence of some upper-level clouds. The stubborn ridge continues to
drive high temperatures into the mid to upper 70s, with some areas
possibly exceeding 80 on Sunday depending on the thickness of the
clouds. Dry air will allow for radiative cooling overnight keeping
low temperatures in the upper 40s to low 50s, with the 40s
predominately being in the river valleys and southeastern MO and
southwestern IL. This is due to the presence of fewer clouds in that
region, which will allow for more efficient radiative cooling
overnight.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Issued at 228 AM CDT Sat Oct 24 2026

Over the western CONUS, a deep upper-level trough is present and is
expected to propagate to the northeast toward the north-central
CONUS and into the Midwest during the middle of the week. Guidance
is in good consensus that as the trough tracks northeast it will
reduce the amplitude of the ridge over the region. The current
forecasted track of the trough will cause the associated cold front
to stay well to the north of the region, resulting in dry and
seasonably warm conditions in the region continuing through the
entire week. High temperatures will remain in the 70s each day.

Earlier guidance had indicated a potential pattern change at the end
of the week, but latest model trends indicate stronger confidence
that the ridge remains in place through the end of the week.
Yesterday, the NBM and LREF guidances continued to hint at the
possibility of a cold front coming at the end of the week with IQRs
of 10-15 degrees for Thursday and Friday, but latest runs have IQRs
of 5-10 degrees by raising the 25th percentile from being in the 60s
to being in the low 70s. At the same time, this model trend has also
decreased the chance of rain at the end of the week down to 10-30
percent on Friday while increasing the chances the following weekend
ahead of the potential cold front.

&&

.AVIATION /06Z TAFS THROUGH 12Z SUNDAY/...
Issued at 1220 AM CDT Sat Oct 24 2026

High pressure continues to bring calm winds and VFR conditions.
There continues to be a daily threat of fog in the valleys each
morning, but thus far some high level cirrus clouds are
providing enough of a blanket tonight to make this less likely
than previous nights. However, if these clouds disperse then
locally greater cooling may lead to local instances of fog
through 12 or 13Z. The greatest chances are at SUS or CPS.

&&

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

&&

$$

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