St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

703
FXUS63 KEAX 221952
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
252 PM CDT Tue Sep 22 2026

.KEY MESSAGES...

- Seasonable temperatures continue this week.

- Precipitation chances (30-50%) return to the forecast Friday
  through the weekend.

&&

.DISCUSSION...
Issued at 250 PM CDT Tue Sep 22 2026

The first day of Fall comes in with classic Fall weather. Highs
will be in the upper 60s and lower 70s across the area with
mostly cloudy skies and a few peeks of sun through the
afternoon. The 500-hPa pattern has taken an interesting
evolution over the past few hours. Mid-level troughing has dug
into the West Coast while ridging from Texas to the central
Rockies has shifted slightly east and ridging over the Great
Lakes has remained fairly stagnant. This has created a ridge
over ridge setup, however, there is a shortwave embedded between
them with an associated weak jet maxima placed over the MO
River Valley. At the surface, a broad surface high has been
gradually shifting east across Ontario and Quebec, decreasing
its influence across the lower MO River Valley. An inversion
around 850-hPa has trapped a layer of moisture near the surface
and resulted in the cloud cover that has been persistent over
the past couple of days. Model soundings depict weak instability
beneath the inversion, which has provided enough support to
induce some pockets of drizzle/light rain. This will continue
through the afternoon, gradually shifting east with time.

The ridge over the Great Lakes and the shortwave will move to
the east over the next day or so allowing the southern ridge to
take hold over the area. With the shortwave out of the area,
drier mid-level air will advect into the area and skies will
be able to clear through the day tomorrow. Temperatures will
remain in the low-to-mid 70s, with dew points in the upper 50s,
creating a pleasant Fall day. This pattern remains through the
end of the week.

Several shortwaves are expected to move through the flow
inducing showers, however, precipitation should remain to the
north and west of the area through Thursday. On Friday, a more
vigorous shortwave is progged to move through the flow and shift
the ridge to the east, allowing showers to move into the area
from northwest to southeast through the day on Friday. Several
more impulses bring shower chances (30-50%) to the area through
the weekend. Instability looks to be minimal with these
systems, so even as much as thunder may be hard to come by.

Long range deterministic and ensemble models are in fairly good
agreement for mid-level ridging to build back into the Central
CONUS by early next week. This would likely allow temperatures
to climb back into the low-to-mid 80s.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1217 PM CDT Tue Sep 22 2026

MVFR conditions are expected through the majority of the TAF
period at all four terminals. CIGs have improved a little
faster than previously forecast, so have gone with high-end MVFR
out of the gate. There has been some scattered DZ/BR around
this morning, that has dropped visibilities down to 2-4 miles
when it impacts the terminals. This should slide off to the east
through the afternoon, but have opted for a TEMPO group for the
first 3 hours of the TAF period at KMCI, KMKC, and KSTJ. CIGs
will drop again overnight, but should stay above IFR before
finally scattering out into VFR conditions tomorrow morning.
Winds will be fairly light (5-10 kts) out of the northeast/east
through the period at all four terminals.

&&

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

&&

$$

DISCUSSION...Carothers
AVIATION...Carothers