Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

274
FXUS63 KLSX 151731
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
1131 AM CST Sun Nov 15 2026

.KEY MESSAGES...

- The weather will remain dry through at least the middle of
  next week under the influence of a strong high pressure
  system. Cooler than normal temperatures will warm a few
  degrees each day through the middle of the week.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 311 AM CST Sun Nov 15 2026

Cool and dry weather will continue today as a sprawling surface high
dominates the pattern.  Forecast soundings show little moisture
available to produce clouds, so expect full sunshine today and
continued clear skies tonight.  Temperatures will rebound into the
low and mid 50s with full sunshine today and the clear sky and light
winds tonight will once again be ideal for radiational cooling.
Temperatures should fall below freezing into the mid and upper 20s
once again in most locations, although more urbanized parts of the
St. Louis Metro Area may only dip into the low 30s. The surface high
drifts a bit farther east into the Ohio Valley on Monday which turns
the low level flow more to the south and southeast, warming highs a
few more degrees into the mid and upper 50s.  Slightly warmer
temperatures Monday afternoon lead to slightly warmer
temperatures Monday night, though lows still drop into the mid
20s to low and mid 30s through radiational cooling.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 311 AM CST Sun Nov 15 2026

The high continues to influence our weather through much of the
remainder of the week as it drifts east into the Mid Atlantic
Region. Temperatures warm above normal Tuesday, and continue a slow
warming trend through the end of the week in persistent southerly
flow on the western side of the ridge.  Global deterministic
guidance continues to show a short wave trough moving off the
Rockies Wednesday and into the Midwest Wednesday night.  The GFS and
ECMWF are in better agreement this morning than in previous runs
with this wave and the attendant surface cold front Thursday.  The
surface ridge axis is forecast to extend across the deep south,
blocking moisture return from The Gulf by late Wednesday into
Thursday.  Both models now show little if any precip reaching our
area for lack of moisture return due to the blocking ridge as the
front moves into northern Missouri and central Illinois on Thursday
before stalling.  The NBM has accordingly scaled back PoPs to less
than 20 percent across the area except for northeast Missouri. Fewer
than 20 percent of the LREF members are showing any precip for
Thursday and Friday with the front in the vicinity as well, which
lends confidence to a dry forecast for that period.  The next
upstream short wave moves across the Rockies into the Great Plains
early Saturday.  Models indicate this second wave will be stronger
than the first, resulting in a stronger low level cyclone and better
moisture return.  The ECMWF and GFS both show some modest low level
moisture convergence ahead of the low level wave across the Mid
Mississippi Valley, resulting in 1-2 tenths of an inch of QPF.  Both
the NBM and LREF also increase the probability for precip to 30-50
percent for much of the area, and up to 60 percent for parts of
northeast and central Missouri.

&&

.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1130 AM CST Sun Nov 15 2026

The main and only concern this TAF period will once again be the
development of river valley steam and radiation fog Monday morning
given only slight changes to current weather pattern. KSUS and KCPS
are most favored to see impacts from fog. Otherwise, light
variable to southeasterly winds will prevail.

&&

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

&&

$$

SHORT TERM...Carney
LONG TERM...Carney
AVIATION...Pfahler