St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

102
FXUS63 KEAX 300510
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1110 PM CST Sat Nov 29 2025

.KEY MESSAGES...

* Gusty NW winds and coldest air of season settle in as winter storm
  system exits eastward this evening.
  - NW winds and gusts into the 20s and 30s mph respectively
    this evening and overnight
  - Highs fall into 20s for Sun/Mon

* Another round of snowfall likely for Monday
  - Currently best chances along/north of I-70
  - All snow, a couple to few inches possible
  - Could affect morning and evening commutes

&&

.DISCUSSION...
Issued at 257 PM CST Sat Nov 29 2025

The mid-upper level wave responsible for the ongoing winter storm
system continues to move across the Plains this afternoon. It has
pivoted to take on a negative tilt, while its surface low reflection
has glided NE out of SE Kansas and currently resides across north-
central Missouri. This too has pushed bulk of notable precipitation
eastward toward IL/WI. Remaining precipitation within the CWA and
state in general is primarily light in nature and continues to range
from rain (S of US-36) and snow (N of US-36) ahead of the cold front
and then some brief light snow accompanying the post-cold frontal
passage back over portions of western Missouri.

Now as for what transpired through the day... for the most part, the
forecast carried out as anticipated. There was a tight rain/snow
line that gradually lifted northward with the surface low and warm
front, yielding majority of accumulating snow around/north of
Maryville to Chillicothe to Moberly. This was generally a county or
so further south than initially forecast, which too led to some
heavy accumulations >6" into the Winter Weather Advisory areas of
Grundy/Linn/Macon/Randolph counties. Fortunately, the lifting warm
front significantly limited travel hazards and accumulating snowfall
outside of the Advisory area. By early this afternoon, cold front
too had entered W/NW portions of the CWA. And coupled with a
building surface high over the Northern Plains, yielded quick
introduction of strong and gusty NW winds with sites already
reporting sustained winds into the mid 20s mph and wind gusts into
the mid and upper 30s mph. As the mid-upper level wave and surface
continue to exit the area to the NE, the cold front and strong NW
winds will overspread the wider area and allow these gusty
conditions to continue through much of the overnight before any
notable easing. Expect gusts at least into the low-mid 30s mph
throughout. This too will help usher in the coldest air mass of the
season, yielding highs only into the 20s deg F for Sun/Mon.
Fortunately some cloud cover will help limit the bottom from falling
out overnight tonight and Sunday night, but too will be cold in the
lower 10s to teens in most cases.

Looking forward, cold start to the week, which too will see another
opportunity for widespread wintry precipitation. The 12z synoptic
(GFS/Canadian/Euro) guidance runs and ensembles are in remarkably
good agreement on the timing and location of this next mid-upper
level wave affecting the area on Monday. Fortunately, lack of any
low-mid level support off the Rockies prevents any surface
reflection development as the wave traverses the Rockies late this
weekend and Monday. Deterministic Euro/GFS suggest potential for
widespread light accumulations and a corridor of potentially
moderate accumulations. This too is reflected within individual
ensemble depictions, though with the typical variability in location
and magnitude. Looking at cross sections Monday, there is notable
FGen forcing in/around the 700mb level, including the potential for
some at least transient slant wise instability as seen in EPV* and
Theta-E contours. As noted, no doubt it will be all snow given the
Arctic airmass that will be in place. And higher end amounts may be
limited with initial dry airmass to overcome (top down saturation)
and depicted limited DGZ depth. However, soundings do denote that if
conditions end up a degree or two colder, much of the column and
especially the region of greatest lift, may reside in the DGZ. Near-
surface winds too appear poised to be on the lighter side, limiting
fracturing. As with any banding, the area of greatest snowfall will
likely be fairly narrow, on the order of the width of a county or
two. At this point in time, ensembles and NBM probabilities do show
greatest (significant actually) confidence in areas N of I-70. This
includes probabilities of 1" or greater of >90% in
GFS/Canadian/ECMWF ensembles and >80% in the NBM (which is heavily
influenced by that trio at that time point). While banding likely
washed out in the coarser ECMWF/Canadian at that time, GFS does
paint a stripe of >40-50% probability for 3" or greater N of I-70 as
well. Main takeaway here is for at least light accumulations
appearing likely for central to northern Missouri, and the potential
for moderate to borderline heavy accumulations where mid-level
banding does occur. Timing currently suggest potential to impact one
or both of the morning and evening commutes as well. Fortunately,
the time over which this snowfall may occur may help quell robust
impacts to travel but may conversely yield prolonged at least
nuisance impacts.

Some limited moderation of temperatures through the work week as the
large scale flow goes more zonal, but lack of strong surface flow
will prevent too much more than 30s highs in most cases. And even
less moderation over snowpack areas. After the Monday snow
potential, next opportunity may be late week as a mid-upper level
wave drifts out of the SW CONUS and into the Southern/Central
Plains.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1110 PM CST Sat Nov 29 2025

MVFR cigs are expected to prevail thru 22Z-00Z when they are
forecast to become bkn and lift to 3-4kft. Winds will be out of
the NW btn 15-20kts with gusts to 25-30kts thru 15Z-16Z aft
which winds will relax and become NW/NNW btn 10-15kts. Aft 23Z
winds will become northerly and diminish to 5-10kts.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.

&&

$$

DISCUSSION...Curtis
AVIATION...73