St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

244
FXUS63 KEAX 211114
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
614 AM CDT Mon Sep 21 2026

...Updated 12z Aviation...

.KEY MESSAGES...

- Fog Possible Monday Morning with Light Rain Activity

- Cool Fall Temperatures This Week

- Rain Returns Friday

&&

.DISCUSSION...
Issued at 307 AM CDT Mon Sep 21 2026

Surface cyclone has pushed southeast of the area while surface high
pressure centered over the Upper Midwest spreads across much of the
central CONUS. While there is not a lot of forcing at the surface,
an H5 trough is moving across the Central Plains which will inhibit
mid-level height rises. This will be just enough lift today to
maintain cloud cover for most of the morning and afternoon hours.
This may also help the development of light rainfall activity,
drizzle, or sprinkles across the area especially prior to noon
today. However, temperatures will remain notably cooler throughout
eastern Kansas and Missouri today. If there is any type of light
rain or drizzle activity today, this is expected to diminish but low-
level moisture may keep lower-level clouds in play through the
evening.

Tuesday and Wednesday, H5 ridge axis amplifies over the Front Range
and High Plains, and will provide height rises into the lower
Missouri River Valley and allow the surface high pressure to expand
across much of the region. This will help keep conditions mostly dry
through the middle of this week. Low-level flow will generally be
northeasterly to easterly, limiting any notable temperature
advection regimes. Therefore, will maintain high temperatures in
upper 60s for areas along Hwy. 36 and northward, with lower 70s
southward. Overnight lows will dip into the lower 50s across much of
the area, with locations near the Iowa border potentially dropping
into the upper 40s.

Thursday and Friday, troughing over the Pacific Northwest will work
to de-amplify the mid-level ridge pattern across the central CONUS,
sending a series of vort maxima toward the Upper Midwest and lower
Missouri River Valley. A weak thermal ridge should push eastward,
and provide modest warm air advection that aids temperatures getting
back into the mid 70s toward the end of the week. This will also
provide our next opportunity for rain shower activity. Current
ensemble guidance favors western Missouri and eastern Kansas for
activity starting late Thursday and continuing into Friday with 30-
40 percent probabilities for measurable rainfall. This then expands
eastward into Central Missouri through the remainder of the weekend.
Some model guidance does attempt to push temperatures back into the
80s by the end of next weekend, but cloud cover and rain shower
potential may largely limit that potential, and current spread
amongst ensemble guidance is fairly large for temperature forecasts
next weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 611 AM CDT Mon Sep 21 2026

Low-level moisture will maintain IFR ceilings for much of the
morning. There are pockets of drizzle and fog out there that may
also drop visibilities to IFR as well. Improvement to MVFR for a
few hours this afternoon is expected, but IFR conditions are
likely to return late tonight and early Tuesday morning.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...Krull