Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

748
FXUS63 KLSX 280007
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
607 PM CST Fri Feb 27 2026

.KEY MESSAGES...

- Warm, dry, and breezy conditions will lead to Elevated Fire
  Danger on Saturday across northeastern Missouri, west-central
  Illinois, and the Ozarks.

- A winter weather system will bring snow and impacts to areas north
  of I-70 Sunday night into Monday morning. A wintry mix to rain
  is expected along and south of I-70.

- Multiple rounds of soaking rainfall are expected next week.


&&

.SHORT TERM...  (Through Late Saturday Night)
Issued at 226 PM CST Fri Feb 27 2026

Broad troughing is present over a majority of the CONUS today, with
the Middle Mississippi Valley being beneath northwesterly flow. A
shortwave within this flow is associated with a low traversing
southern Canada and the Northern Great Lakes region, and it`s
attendant cold front can be seen in surface observations extending
from Wisconsin southwestward through Iowa and Kansas. The
precipitation and even cloud-free nature of this front is reflective
of how dry the boundary layer is across much of the region, with RH
locally being roughly 30% or lower. Thanks to the tight pressure
gradient caused by the low, winds have been gusting out of the
southwest, further warming temperatures thanks to downsloping off
the Ozarks. This all supports our anomalously warm day today, and
the Red Flag Warning remains on track. Outdoor burning continues to
be strongly discouraged through this evening.

The aforementioned cold front drops through the CWA this evening and
tonight, causing winds to become light and variable. The post-
frontal air mass will lack bite thanks to weak cold air advection
and it will quickly slide through the Midwest, leading to winds
remaining variable through the night into Saturday morning. A weak
surface reflection moving eastward across the Middle Mississippi
Valley through the day Saturday will shift winds southerly for areas
along and south of Highway 36/I-72, leading to another day of well
above-normal temperatures for much of the area. These warm
conditions paired with a still dry boundary layer and breezy
conditions will lead to another day of Elevated Fire Danger across
portions of northeastern Missouri, west-central Illinois, and the
Ozarks.

The surface reflection and another front dropping through region has
a low chance (~20%) of forcing light rainfall mainly along and west
of the Mississippi River during the late morning and afternoon. This
second cold front will pack more of a punch due to its Arctic
nature, with temperatures Saturday night falling below freezing for
areas along and north of I-70.

Elmore

&&

.LONG TERM...  (Sunday through Next Friday)
Issued at 226 PM CST Fri Feb 27 2026

The main focus for Sunday continues to be a weak wave aloft inducing
cyclogenesis over the Southern Plains and Mid-South late Sunday into
Monday. Guidance remains stubbornly spread, making specifics
uncertain. Confidence is at least high in timing, as while the NAM
continues to be an outlier with a Monday morning onset, a majority
of deterministic and ensemble guidance favors precipitation
spreading eastward Sunday evening and dissipating by noon on Monday.
Wintry precipitation, with confidence high in it being snow, is
expected north of I-70 where temperatures through the lower
atmosphere are expected to be below freezing. Here, QPF among
guidance consensus continues to trend slightly downward, and there
is concern that initially warm ground temperatures paired with near
freezing surface temperatures may at least cut into accumulation
potential at first. However, brief periods of lift focused within
the dendritic growth zone north of I-70 will favor short lived
bursts of greater snowfall rates that will overcome the previously
mentioned limiting factors to produce accumulating snowfall.
Generally, 1-2" of snowfall is expected, with localized areas seeing
as much as 4".

Along and south of the I-70 corridor, surface
temperatures are forecast to be right at or just above freezing, and
vertical profiles show a warm nose occasionally nudging in. Rain to
a rain/snow mix would result, and brief periods of freezing rain
would result along I-70 for locations where surface temperatures are
subfreezing and a warm nose develops aloft. However, the chance for
impacts is low, as ground/pavement temperatures will limit
accumulations mainly to elevated and grassy surfaces.

While this round of precipitation dissipates by mid-day Monday, it
is the first of several expected through the week. Guidance
consensus is that quazi-zonal to increasingly northwesterly flow
will prevail through the upcoming workweek, allowing for multiple
disturbances to pass through the region. These disturbances will
produce additional rounds of precipitation starting as soon as
Monday night and early Tuesday. The 25th percentile of global
ensemble members keeps temperatures right at or above freezing
through this period, leading to high confidence in temperatures
being warm enough to support mostly rain. In fact, as warmth builds
toward the end of the week, the chance for thunderstorms increases.
While some AI/ML-based guidance produces low probabilities for
severe thunderstorms by the end of the week, favorable instability
and shear space for severe storms among deterministic guidance has
very little if any overlap, leading to very low confidence in this
threat.

Elmore

&&

.AVIATION...  (For the 00z TAFs through 00z Saturday Evening)
Issued at 526 PM CST Fri Feb 27 2026

Mainly dry and VFR condtions are expected through the period. The
only exception will be a low chance (20-30%) for light rain at
COU/JEF and the St. Louis metro terminals between 15-21Z.
Confidence is too low at this point to include in terminals.
Otherwise, west to southwest winds are expected to decrease early
this evening and then turn to the northwest behind a cold front
this evening before slowly backing out of the east and southeast
on Saturday.

Britt

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Red Flag Warning until 6 PM CST this evening for Audrain MO-
     Boone MO-Callaway MO-Cole MO-Franklin MO-Gasconade MO-Knox
     MO-Lewis MO-Lincoln MO-Marion MO-Moniteau MO-Monroe MO-
     Montgomery MO-Osage MO-Pike MO-Ralls MO-Saint Charles MO-
     Saint Louis City MO-Saint Louis MO-Shelby MO-Warren MO.

IL...Red Flag Warning until 6 PM CST this evening for Adams IL-Brown
     IL-Calhoun IL-Greene IL-Jersey IL-Macoupin IL-Madison IL-
     Pike IL.

&&

$$

WFO LSX