878
FXUS63 KLSX 052007
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
207 PM CST Thu Nov 5 2026

.KEY MESSAGES...

- A light freeze is likely (>60%) this weekend, mainly in rural
  areas and river valleys.

- Dry conditions with moderating temperatures are expected late
  this weekend into next week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 205 PM CST Thu Nov 5 2026

A cold front is currently nearing the I-44/I-55 corridors in
Missouri and Illinois respectively. This boundary will push
through the remainder of the CWA over the next few hours, with
surface winds veering to the northwest and stratus advecting in
its wake. A few light rain showers are also expected this
afternoon/early evening, mainly across parts of northeast
Missouri and west-central Illinois beneath steeper midlevel
lapse rates associated with a trough axis. Later on tonight, the
setup looks more conducive to patchy/areas of drizzle beneath
the stratus deck due to weak low-level convergence.

Temperatures tonight are forecast to drop back into the low to mid
40s from north to south, as the air mass coming into the region is
not strong for this time of year. In addition, brisk north/northwest
winds and plenty of low stratus clouds help prevent radiational
cooling. Low-level dry air is expected to work its way into the area
from north to south on Friday, so look for decreasing clouds by
afternoon. High temperatures are forecast to be in the upper 40s to
low 50s, or about 10 degrees below normal for the date.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 205 PM CST Thu Nov 5 2026

(Friday Night - Saturday Night)

The focus for both Friday and Saturday nights is on the potential
for the first freeze this fall in the region. The coldest night for
most locations is expected to be Friday night based on the timing of
the surface high, though portions of southeast Missouri in favored
river valleys may be as cold, if not slightly colder, Saturday
night. Widespread low 30s are forecast across the region Friday
night, with the exception of the urban heat island of metro St.
Louis (mid to upper 30s). A few spots may drop into the upper 20s,
mainly in central/northeast Missouri as well as west-central
Illinois. This is where the REFS probabilities for subfreezing low
temperatures are highest (60-70%). The surface high Saturday night
is retreating slowly across southeast Missouri and southwest
Illinois. Lows in the low 30s are forecast in these locations, with
mid 30s to the northwest due to increasing southwesterly surface
flow.


(Sunday - Next Thursday)

There remains high confidence in a dry weather pattern with
moderating temperatures late this weekend into early next week. By
Monday, high temperatures are expected to be back well into the 60s,
with lows in the 30s/40s. Forecast uncertainty increases mid/late
week with respect to the strength and location of a mid/upper level
trough moving across the Great Lakes/northeast. There is quite a bit
of spread with this feature, with two of the four clusters of the
500-hPa height pattern from the LREF showing a deeper trough closer
to the Great Lakes, while two other clusters are weaker and farther
to the east. While mostly dry weather is likely to continue in
either scenario, a stronger trough across the Great Lakes would have
the potential to send us the coldest air so far this season. The
temperature spread on the NBM expands considerably between Tuesday
and next Thursday, with differences between the 25th/75th
percentiles over 10 degrees for both highs and lows in some
locations.

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 1114 AM CST Thu Nov 5 2026

A cold front has recently moved through KCOU/KJEF and is
forecast to move through the metro terminals later this
afternoon. Look for winds to veer to the west/northwest behind
the boundary along with MVFR ceilings. These lower ceilings
should continue overnight before advecting out from north to
south Friday morning. Some light rain showers and/or drizzle are
also possible, though visibilities are likely to stay VFR. The
exception may be at KUIN this afternoon. Have a TEMPO for low
MVFR visibilities due to these scattered rain showers behind the
front.

&&

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

&&

$$

SHORT TERM...Gosselin
LONG TERM...Gosselin
AVIATION...Gosselin