Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

096
FXUS63 KLSX 082024
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
224 PM CST Sun Nov 8 2026

.KEY MESSAGES...

- The next chance (30-40%) for light rain on comes on Wednesday.

- Temperatures will start the week above normal (highs in the
  60s- 70s) and end the week below normal (highs in the
  40s-50s).

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 217 PM CST Sun Nov 8 2026

Upper-level ridging can be seen in water vapor imagery building
eastward into the Middle Mississippi Valley as the trough from late
last week continues to move through the Northeast. The building
ridge is pushing the surface high responsible for our recent weather
gradually eastward. With this, low-level ridging is building into
the region, with increasingly southwesterly flow weakly advecting
warmer air over the CWA. As a result, temperatures this afternoon
are trending about 10 degrees warmer than at this point yesterday.
This general pattern holds through Tuesday, with daily temperatures
running about 10 degrees above normal through this stretch.

Overnight lows tonight will still be cool enough to lead to a threat
of valley fog mainly over the Ozarks. The surface high`s gradual
shift eastward is expected to mostly mitigate fog development
Monday and Tuesday nights.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 217 PM CST Sun Nov 8 2026

A strong upper-level trough will impact our local weather through
the duration of the extended forecast period. Guidance consensus is
that this trough will begin rapidly digging into the eastern half of
the country on Wednesday, with an initial shortwave passing through
the Middle Mississippi Valley then. Over the last 24-36 hours, a
majority of guidance has this wave inducing cyclogenesis somewhere
over the Central or Southern Plains and tracking the low
northeastward through the Midwest. While there is much spread in the
track of this low among guidance, confidence is increasing that it
or at the very least its cold front will directly impact the CWA.
This has led to increasing chances (currently 30-40%) for rainfall
across portions of the CWA, with these chances expected to increase
as guidance spread decreases in the coming days. Both
instability and QPF are meager with this system, so severe
weather and heavy rainfall are not expected. While the forecast
beyond Wednesday is dry, additional rounds of light rainfall
cannot be ruled out through Friday-Saturday as additional
shortwaves rotate through the trough. At this lead time,
guidance does a notoriously poor job at accurately resolving
these subtle features, hence the dry forecast.

Possibly the bigger story with this trough is a blast of late fall
air that will move into the region to end the week. With guidance
consensus showing an increasingly potent trough, temperatures among
ensembles and deterministic guidance continue to cool. In the wake
of Wednesday`s surface system, below normal temperatures are
expected at least Thursday and Friday, with Friday being the
cooler of the two days. Then, nearly all guidance has a majority
of the CWA seeing highs in the 40s. Confidence in temperatures
as we head into the weekend decreases significantly as guidance
diverges on the phasing of the trough and how quickly it departs
the area. Temperatures will moderate; though how quickly is
uncertain at this lead time.

&&

.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1101 AM CST Sun Nov 8 2026

The main threat to VFR flight conditions through the forecast
period is another round of fog tonight. This fog is expected to
be confined mainly to river valleys, with confidence highest in
impacts at KJEF, KSUS, and KCPS; though, at least brief impacts
can`t be ruled out at KUIN, KCOU, and KSTL.

&&

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

&&

$$

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