797
FXUS63 KLSX 091705
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1105 AM CST Sun Nov 9 2025

.KEY MESSAGES...

- The coldest temperatures of the season so far will occur today
  and Monday before warming kicks off for the remainder of the
  week.


&&

.SHORT TERM...  (Through Late Monday Afternoon)
Issued at 251 AM CST Sun Nov 9 2025

Yesterday`s cold front has moved through the area and temperatures
are dropping as the anomalously cold airmass surges into the region.
The tight surface pressure gradient is resulting in elevated winds
and a continuation of the 20-30 mph gusts that entered the region
immediately behind the cold front. Cloud cover will linger across
the region through most of the day and combined with the robust cold
air advection will lead to a shallow diurnal curve. Temperatures
will peak not much higher than their morning lows, in the 30s.

Aloft the mid-level trough remains in place over the broader Great
Lakes region, and another shortwave disturbance will push through
the area today. Coupled with some 700-600mb frontogenesis, this may
be enough to squeak out some flurries here and there across the
forecast area today. Winds will remain elevated with gusts between
20-30 mph, so any flurries that develop will fracture, becoming
quiet fine when they reach the surface. No accumulation will occur.

Temperatures will drop into the upper teens to low 20s overnight,
the coldest we`ve seen this side of summer and the first hard freeze
of the season. The cold start and continued cold air advection will
offset the sunny sky on Monday, and temperatures will only be able
to warm a few degrees more than today. Winds will finally diminish
Monday evening as a surface high pushes across the lower Mississippi
Valley, loosening the surface pressure gradient.

Delia

&&

.LONG TERM...  (Monday Night through Saturday)
Issued at 251 AM CST Sun Nov 9 2025

The surface high will push into the Deep South overnight and into
Tuesday morning, causing southwesterly surface flow to establish
across the mid-Mississippi Valley. This will be mirrored in the low-
levels while aloft the mid-level trough will slide east, allowing
northwesterly flow to establish. The southwesterly low-level and
surface flow will kick start a warming trend that will continue
through the week. Despite a cold start in the 20s and high level
clouds through most of the day, 30 degrees of warming is still
expected with highs on Tuesday reaching into the 50s.

Northwest flow aloft will continue through the mid-week period as
the region remains stuck between the departing trough and an
approaching ridge that will be positioned over the West Coast.
Southerly to southwesterly surface low will continue through mid-
week and combined with increasing sunshine and warmer morning lows
than Monday will result in temperatures warming back above normal.
By the end of the work week the mid-level flow becomes more
progressive, and the ridge shunts eastward, driven by a trough
approaching the West Coast. Southwest flow aloft develops over the
end of the work week and into the weekend, giving another boost to
warming temperatures. There is a 40-50% chance temperatures will
exceed 70 degrees during the first half of the weekend. By the end
of the period the mid-level trough from the West Coast will approach
the mid-Mississippi River Valley, bringing the next best chance of
rain to the region. Differences in timing, strength, and position
result in uncertainty at this time in when and how much rain we`ll
receive.

Delia

&&

.AVIATION...  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1102 AM CST Sun Nov 9 2025

Gusty northwest winds are the main story through Monday morning.
Gusts around 25-30 knots are expected through this afternoon
before they weaken closer to 18-20 knots tonight into Monday. Any
remaining MVFR stratocumulus should quickly lift to near 4-5 kft
AGL very early this afternoon. VFR conditions and mostly dry
weather are forecast then through the period. Some flurries are
possible overnight, but no visibility restrictions are expected.

Gosselin

&&

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

$$

WFO LSX