Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

838
FXUS63 KLSX 260749
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
249 AM CDT Mon Oct 26 2026

.KEY MESSAGES...

- Seasonably warm temperatures with mostly dry conditions will
  continue through Friday.

- Chances of light rain return this weekend, but a widespread
  significant (0.50+") rain is not likely.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 249 AM CDT Mon Oct 26 2026

GOES-19 nighttime microphysics satellite imagery shows
thickening cirrus clouds moving from southwest to northeast
toward the Mississippi Valley. This increase in high-level cloud
cover has limited the nocturnal temperature drop slightly
overnight, with current readings on average about 3-5 degrees
warmer than 24 hours prior. Increasing and thickening high
clouds are forecast through the morning hours, before some
clearing moves into western sections of the CWA during the
afternoon. Due to the aforementioned clouds, high temperatures
today are not expected to be as warm as Sunday, with readings
topping out mostly in the mid 70s. There may be a few spots that
get into the upper 70s though in central Missouri if the
clearing works its way in a bit sooner than forecast.

A midlevel shortwave trough is forecast to move slowly out of the
south-central Plains and across the mid-Mississippi Valley late
tonight through Tuesday evening. The main impact with this feature
should be a notable increase in midlevel clouds, which should lead
to slightly cooler temperatures (low to mid 70s) on Tuesday. A few
spotty sprinkles cannot be ruled out, but the mid/upper level
forcing for ascent is not that strong and there is a very deep (15+
kft AGL) layer of dry air to overcome.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 249 AM CDT Mon Oct 26 2026

(Tuesday Night - Friday)

The pattern remains largely stagnant through the end of the work
week with our region sitting beneath quasi-zonal flow aloft. A weak
cold front is forecast to approach parts of northeast Missouri late
Wednesday night before stalling out and lifting back north as a warm
front later in the week. There is a low chance (20-30%) of rain
showers and possibly a thunderstorm or two in the vicinity of this
cold front, mainly across northeast Missouri and west-central
Illinois.

Temperatures are forecast to moderate through Thursday, with most
locations getting back into the low 80s to the southeast of the cold
front. At least slightly cooler highs (upper 70s to near 80 degrees)
are expected on Friday, mainly due to increasing mid/high level
clouds.


(Friday Night - Sunday)

Ensemble guidance is in reasonably good agreement that another
midlevel shortwave trough will move across the south-central Plains
into the mid-Mississippi Valley this weekend. There remains some
subtle timing differences, but the shortwave looks somewhat
reminiscent of the one working its way across the region early this
week. The shortwave itself is not particularly strong or organized,
and gradually weakens with time as it gets sheared out as it moves
into more confluent flow aloft. The best chances (30-50%) of light
rain showers are on Saturday afternoon/night as a wing of relatively
modest low-level moisture convergence moves from southwest to
northeast. At this point in time, the rain looks to stay on the
light side with plenty of dry time this weekend. The chances of a
widespread, significant (0.50+") rain looks very low. The latest
LREF probabilities for 0.50+" through this weekend are only in the
10-25% range from north to south, and have been dropping over the
past 24-36 hours.

A mostly cloudy weekend is certainly expected regardless of how much
rain falls, which should help keep low temperatures on the mild side
(mid 50s to near 60 degrees). Highs each day are expected to be in
the low to mid 70s. While still several degrees cooler than mid/late
week, these values would still be about 10 degrees above normal for
late October.

&&

.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1033 PM CDT Sun Oct 25 2026

Dry, VFR conditions will persist through the period. The
potential for fog, primarily at KSUS, is a bit higher tonight
than it appeared a few hours ago. That said, high clouds
overhead are still working against radiative cooling and may
keep conditions just warm enough to preclude much fog.

&&

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

&&

$$

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