St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

918
FXUS63 KEAX 040914
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
414 AM CDT Fri Sep 4 2026

.KEY MESSAGES...

- Well above normal temperatures are expected to continue
  through the weekend and into next week.

  - Extreme Heat Warning in effect through 8 PM Saturday area wide

  - Extreme Heat Warning in effect through 8 PM Tuesday for areas
    along and south of a line from St. Joseph MO to Booneville
    MO

- Very limited chances for any measurable precipitation through
  the weekend and into next week for much of the area.

&&

.DISCUSSION...
Issued at 413 AM CDT Fri Sep 4 2026

There are only so many different ways you can talk about the current
and prolonged heat across the area. So, keeping the take home point
simple ... the heat continues for at least another few days for a
good portion of the area.

Synoptically speaking, not much change from cycle to cycle among the
deterministic or ensemble guidance. Pattern evolution over the next
couple/few days remains well signaled among the flagship
deterministic models and their accompanying ensembles. This takes
the existing Omega-block look to the pattern and really just squats
it over the CONUS into early next week. The more subtle evolution
will see the central ridge axis  drift/retrograde westward and
amplify as the eastern cutoff low churns down into/around New
England and the PNW cutoff struggles to make any headway. Aside from
the continued heat, this too continues to keep any appreciable
precipitation chances primarily north of the area through the
weekend. Expect conditions through the weekend tending to be repeats
of the last couple/few days with highs ranging from the mid 90s to
around 100 and heat index values a few degrees higher up to around
105. All of this is bolstered by very tight ensemble temperature
spreads seen across various visualization tools. No changes to the
first portion of the Extreme Heat Warning given the above.

By Sunday afternoon, there remains signaled some relief for N/NE
portions of the area in response to weak mid-level height falls
(ridge axis drifts ever so slightly further west) and a backdoor
cold front as a large surface high drops into the Great Lakes
region. This pushes highs in those areas down into the low to mid
90s. Unfortunately, relief quickly peters out and leaves areas S and
W of a line from around Maryville MO to Booneville MO left baking in
heat. Ensemble guidance remains quite confident in that heat with
NBM probabilities >70-90 percent for highs of 95 deg F or greater
for locations like St. Joseph, Kansas City and probabilities of 60
percent or greater as far east of Brookfield, Moberly, and Columbia.
With a similar story playing out Monday, this helps allow N/NE areas
of the Extreme Heat Warning to expire Saturday.

Monday/Tuesday, the mid-upper level pattern becomes more
progressive, with the western CONUS cutoff low flattening the ridge
as it moves across the Northern and Canadian Plains. Before it is
able to possibly bring about appreciable temperature relief, later
in the week, Tuesday may be the hottest day of the heat wave as it
pushes 850mb thermal ridge axis over the area. A handful of 100s may
be possible. This too results in these areas remaining in an Extreme
Heat Warning through Tuesday evening. Ensemble temperature spreads
increase substantially mid-late week in response to uncertainty in
just how far south cold front is able to make it.

Throughout this time period, appreciable precipitation will be
abundantly hard to come by. The best opportunities for any
precipitation will tend to be over northern and eastern areas as
shortwaves/disturbances traverse the ridge.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 1044 PM CDT Thu Sep 3 2026

VFR conditions throughout the forecast period. Predominantly
southerly winds through the period. Winds pick up slightly
Friday afternoon and there may be a chance for 5-7kt gusts
between 16Z-18Z but they should die off after that.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 8 PM CDT Tuesday for MOZ020>022-
     028>031-037>040-043>046-053-054.
     Extreme Heat Warning until 8 PM CDT Saturday for MOZ001>008-
     011>017-023>025-032-033.
KS...Extreme Heat Warning until 8 PM CDT Tuesday for KSZ025-057-060-
     102>105.

&&

$$

DISCUSSION...Curtis
SHORT TERM...
LONG TERM...
AVIATION...IPC