Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

714
FXUS63 KLSX 041855
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
155 PM CDT Sun Oct 4 2026

.KEY MESSAGES...

- Dry conditions and warming temperatures are expected through
  the week, with no hazardous weather expected.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 151 PM CDT Sun Oct 4 2026

A shortwave can be seen in water vapor imagery moving the Great
Lakes currently; its cold front moving through northeastern
Missouri and west-central Illinois. Thanks to weak northwesterly
flow and the shortwave displaced northeastward of the area,
this front is lacking punch. Dry air through the lower
atmosphere is even limiting associated cloud cover.

This front slowly makes its way through the CWA this evening and
tonight, with slightly cooler air making its way into the area
through tomorrow. Given the weakness of the cold air advection,
temperatures tomorrow will only trend a few degrees cooler than what
is being experienced today.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 151 PM CDT Sun Oct 4 2026

The main drivers of our local weather through the extended period
will be multiple areas of high pressure passing through the region.
At the start of the period on Tuesday, guidance consensus is that
northwesterly flow aloft will keep Monday`s post-frontal high
gradually moving eastward. This in turn will have low-level flow
out of the southwest for Tuesday and Wednesday due to the high
located well east of the area. Despite continuing northwesterly
flow aloft, the southwesterly low-level flow is ideal for a
quick warm-up due to warm air advection and downsloping off of
the Ozarks. This translates to highs around 80 degrees on
Tuesday and into the mid-80s on Wednesday.

This warm-up will be stalled on Thursday, but to what degree and for
how long is uncertain as guidance diverges on the evolution of key
features into the weekend. Consensus is that another weak,
uneventful cold front will move into the Middle Mississippi Valley
Wednesday night into Thursday and stall over or just south-southeast
of the CWA. The center of the post-frontal airmass will quickly pass
well to the north of the CWA, providing only a minor decrease in
temperatures behind it on Thursday. This front will lift northward
as a warm front thanks to upper-level ridging building into the
region and high pressure shifting eastward. While a majority of
ensemble members favor this solution, when it happens and to
what degree remains uncertain. The spread between the 25th and
75th percentile of ensemble guidance for temperatures hovers
around 10 degrees Friday through the weekend. Despite the
spread, confidence is high that temperatures will at the very
least be above normal thanks to the 25th percentile being in the
upper 70s or warmer.

&&

.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1212 PM CDT Sun Oct 4 2026

Confidence is high in dry and VFR flight conditions through the
forecast period at all local terminals.

&&

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

&&

$$

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