St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

117
FXUS63 KEAX 031954
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
254 PM CDT Thu Sep 3 2026

.KEY MESSAGES...

- Well above normal temperatures are expected to continue into
  next week.

    - Extreme heat warning in effect through 8 PM Saturday
      region wide.

    - Extreme heat warning in effect through 8 PM Tuesday for
      areas along and south of St. Joseph to Boonville.


&&

.DISCUSSION...
Issued at 202 PM CDT Thu Sep 3 2026

Current H5 analysis shows the 594 dam high centered over the
mid south into southern Appalachia between an upper trough
across the Pacific Northwest and another over Ontario and
Quebec, yielding yet another hot afternoon across our CWA with 2
pm temperatures in the mid to upper 90s, with heat indices in
the upper 90s to the lower 100s. The synoptic scale pattern
remains mostly the same through the weekend, with the center of
the H5 high sliding westward over the region tomorrow and
Saturday. This will keep high temperatures in the mid 90s to as
high as 100 degrees max and heat indices in the upper 90s to as
high as 105 for Friday and Saturday afternoon. Due to the long
duration of the heat as well as overnight low temperatures
remaining elevated, went ahead and upgraded the heat advisory to
an extreme heat warning for the entire CWA through 8 PM
Saturday.

By Sunday and into Monday, the center of the H5 high slides a
bit further west toward the Plains, with mid level heights
reducing slightly, especially across northern and NE Missouri
where temperatures and heat indices should be a bit cooler
(especially on Monday). However, temperatures in the upper 90s
and max heat indices in the upper 90s to lower 100s should
continue for areas along and south of roughly a St. Joseph to
Boonville line. By Tuesday, an upper trough moving across the
Intermountain West and into the Northern Plains should push the
center of the H5 high and mid/upper ridge axis back over our
CWA, with the H5 high strengthening back toward 595 dam. This
should yield high temperatures in the upper 90s to near 100
degrees, with max heat indices up to 105 degrees. Thus, the
extreme heat warning has been extended through at least 8 PM
Tuesday for these locations along and south of a St. Joseph to
Boonville line. It is possible that the extreme heat warning may
need to be extended into Wednesday, as well.

Increased forecast certainty arrives by Thursday as some
guidance suggests an upper trough moving across the Upper
Midwest and Great Lakes areas and digging southward into the
Ohio Valley on Thursday, potentially sending a cold front into
the CWA from the north sometime Thursday afternoon/evening,
which would bring slightly cooler temperatures and chances for
showers/storms. Other guidance keeps this trough and front
further north, with the heat dome remaining in place overhead
into Thursday and perhaps even Friday. The NBM interquartile
range for MaxT at MCI on Thursday is 87 degrees and 97 degrees,
respectively, and 84 and 94 degrees, respectively, on Friday.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1212 PM CDT Thu Sep 3 2026

VFR conditions will continue throughout the TAF period. Remnant
cloud cover will continue to diminish throughout the afternoon,
and evening, enabling a SKC forecast. Winds will be out of the
SW at 10-15kts with occasional gusts up to 20kts until sunset.
After sunset, winds will stay consistent out of the S and SW
with speeds diminishing to 7-10kts.

&&

.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...BMW
AVIATION...Bjork/Krull