Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

327
FXUS63 KLSX 072018
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
218 PM CST Sat Nov 7 2026

.KEY MESSAGES...

- The area will remain free of hazardous weather through at
  least late next week.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 212 PM CST Sat Nov 7 2026

The upper-level trough responsible for our recent cool down can be
seen in water vapor imagery moving into New England as the center of
a surface high slowly passes over the CWA. This high has local
conditions dry and mainly clear aside from passing high clouds. With
the high only slightly scooting eastward tonight, another round of
efficient radiative cooling is expected, with temperatures falling
in the mid to low 30s, especially over southeastern Missouri and
southern Illinois closer to the center of the high.

Tomorrow, upper-level ridging begins to edge into the Middle
Mississippi Valley, though the region remains beneath at least weak
northwesterly flow aloft. Closer to the surface, low-level ridging
draws closer to the region, with temperatures rebounding at 850 mb
from their lows the previous two days. This, paired with mostly
clear skies, will allow for a notable jump in afternoon temperatures
when compared to today with values in the low to mid-60s expected
for most locations.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 212 PM CST Sat Nov 7 2026

The primary focus during the extended forecast period is a robust
upper-level trough impacting at least the eastern half of the CONUS
during the latter half of next week. Prior to that, guidance
consensus remains that weak, broad upper-level ridging will continue
to build into the Midwest as low-level flow becomes increasingly
southwesterly. This will boost temperatures on Monday compared to
Sunday. Thanks to a warmer start to the day Tuesday and continued
low-level warm air advection, Tuesday will be even warmer, with
global ensemble members tightly focused on highs around 70 degrees.

On Wednesday, the aforementioned upper-level trough will begin
digging equatorward. The majority of guidance continues to trend
toward a solution that supports a more aggressive and westward
trough. This has led to decreasing spread among ensemble members for
our temperatures toward the end of the week, with confidence
increasing in at least a brief period of below-normal temperatures.

Despite this increasing consensus, the phasing of the trough and
more so the embedded shortwaves has and continues to vary greatly
run-to-run and source-to-source. This will dictate specifics on how
quickly we`ll cool, precipitation chances with at least an initial
FROPA, and how quickly temperatures moderate afterwards. If we do
see precipitation with this trough, Wednesday-Thursday is when
confidence is highest it would occur. Despite uncertainty in how
quickly temperatures cool mid-week and rebound later in the weekend,
guidance consensus has consistently shown Friday to be the coolest
day of the period.

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 1138 AM CST Sat Nov 7 2026

MVFR stratus has been stubbornly hanging on over central
Missouri and impacting KCOU and KJEF through the morning, but is
beginning to break up. Additional impacts are expected to be
limited to very early in the period at these two sites. After
that, the next chance for impacts will come tonight via another
round of river valley fog. Given where the coldest temperatures
are expected, confidence is highest in impacts at KSUS and KCPS;
however, there are at least low chances at the remaining local
terminals early tomorrow morning.

&&

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

&&

$$

SHORT TERM...Elmore
LONG TERM...Elmore
AVIATION...Elmore