St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

559
FXUS63 KEAX 241948
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
248 PM CDT Sat Oct 24 2026

.KEY MESSAGES...

- Warm and dry through the weekend. Temperatures trend cooler
  by the end of next week.

- Minimal precipitation chances return Tuesday through Wednesday
  (10- 25% chances, mainly AM); higher potential late week
  (40-60% chances).

&&

.DISCUSSION...
Issued at 248 PM CDT Sat Oct 24 2026

Another dry and warm day across the region. Southerly warm air
advection pushes highs toward 80 degrees for most of the area which
is well above seasonal expectations of 64F. Precipitation chances
for early week remain minimal as rain is more likely to stay north
and west. More widespread precipitation chances return late week;
however, uncertainty remains fairly high with the spatial extent of
synoptic features and associated rainfall.

Beyond the beautiful weather conditions today, water vapor satellite
imagery shows a complex interconnected web of weather systems that
will influence our forecast over the next week. A trough across the
SW CONUS has cut off from the overall flow as anticipated, a ridge
builds across the central CONUS, another low pressure system
migrates through interior Canada, and another trough across the SE
CONUS compliments the western CONUS trough. The satellite picture
yesterday morning did not present such a clear picture of the
emerging weather systems; however, most all guidance did pick up on
the evolution of the SW CONUS cut off low which is one of the
critical influencer in this week`s weather. This does increase
confidence and reduce uncertainties, but does not eliminate them.

All the previous mentioned systems were at the 500mb level, at the
low to mid levels a large high sits over the Ohio Valley as analyzed
on the SPC 850mb analysis. This high has been gradually expanding
westward pushing stable descending air into the region acting as one
of the primary drivers our pleasant conditions over the past
several days. Warm air advection from southerly oriented low to mid
level flow has been pushing our high temperatures well above
seasonal expectations. One other characteristic of this air mass has
been how dry it is with dew points in the 40s. Most sounding
analysis has lifted condensation levels around 7000ft and ceilings
or where the air is much closer to saturation around 20,000ft making
short term PoPs pretty much zero.

One of the most significant components to our weather picture is not
even in the CONUS at this moment. A pair of 500mb lows across Canada
have a midlevel high sandwiched between there respective positions.
This high is expected to eject out toward the central CONUS this
push of cooler Canadian air is expected to promote the development
of a synoptic scale front across the interior of the CONUS, a small
semblance can be seen with clouds across the Dakotas. Ejecting
shortwaves from the SW CONUS low have been sparking off convection
across the boundary for several days. As the midlevel high moves
southeastward, this synoptic front pushes towards our region.
Simultaneously, the low across interior Canada migrates eastward and
the SW CONUS low starts getting absorbed into the overall flow
across the continent. This stretches the frontal boundary almost
wrapping it to the west and north of our region. This also slows the
progression of the lower level high which weakens the thermal and
dynamic gradients of the front. All of this combined with the dry
air in place across our area results in relatively low precipitation
chances (10-20%) Tuesday through Thursday, mainly during the morning
hours. As the front wraps around eastern Nebraska into Iowa much of
the precipitation potential looks limited to far NW MO. Furthermore,
referring to the sounding analysis mentioned earlier, any
precipitation development will have to overcome a fairly deep 5000ft
dry layer before reaching the surface. The lack of significant
temperature gradients, moisture boundaries, and instability, do not
promote much confidence in precipitation potential. However, those
are not enough confidence nudgers to say there will not be rain, it
just has many challenges.

Once the front settled into position it looks to sit there through
the end of next week. Aloft, flow becomes more progressive and the
general divide between the cooler north jet and the subtropical jet
sinks southward. This lowers high temperatures slightly on Tuesday
to the low 70s while shortwave perturbations build up across
Rockies. As the upper level pattern shifts this shortwave pass by
the region being deflected by the still residing lower level high
across the SE CONUS. This deflects systems northward, but does keep
low PoP chances across NW MO Wednesday as they pass by the area.
This also works to bump our high temperatures Wednesday back to the
mid-70s.

Getting to late week ensemble guidance slowly drifts the synoptic
frontal boundary closer to the area. The upper level pattern remains
fairly progressive with more frequent upper level waves moving
across the country. Ensemble guidance suggests this will create a
pattern of frequent midlevel lee troughs progressing along the
boundary using the kinematic and thermal gradients to initiate
showers. This pattern looks to keep rain chances in the forecast
through the weekend. Many uncertainties remain with this solution as
it is heavily dependent on the locations of the front and pressure
perturbations. With this many subtle deviations possible even
deterministic models tend to broad brush precipitation chances.
Uncertainty is likely to narrow as the pattern more firmly
establishes itself Monday and Tuesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1217 PM CDT Sat Oct 24 2026

VFR conditions are expected for the duration of the forecast
period. Winds remain generally southerly through the period.
Winds become lighter overnight and VRB across far northern MO,
but resume out of the south Sunday morning.

&&

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

&&

$$

DISCUSSION...Pesel
AVIATION...Pesel