St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

149
FXUS63 KEAX 251957
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
257 PM CDT Sat Jul 25 2026

.KEY MESSAGES...

- Hazardous heat continues through the weekend, with heat
  indices around 100-110 degF areawide through Monday.

- Low confidence in showers/storms across northern Missouri,
  which could impact heat and humidity.

- Heat/humidity eases up through next week.

&&

.DISCUSSION...
Issued at 255 PM CDT Sat Jul 25 2026

Fog/mist from the early morning has effectively mixed out under
clear, sunny skies with subsidence from an upper-level ridge
situated over the western half of the CONUS. Surface high pressure
to the south/southeast of the forecast area has aided in the
transport of warm, moist air in the low levels, sending heat indices
for most of the forecast area into the triple digits. Areas that
remain under dense cloud cover from the morning will not see their
heat indices rise as dramatically as surrounding areas, but
conditions are still expected to remain muggy and uncomfortable.
This will be the story through the rest of the weekend, with
continued advection of warm/moist air from the south under an
amplified shortwave ridge sending heat indices into the 100-110 degF
range during the daytime. Overnight lows will not offer much
reprieve from the heat, staying above the 70s.

Some uncertainty continues to remain with hazardous heat persisting
through the early week. Embedded shortwaves in the upper-level flow
will "chip away" at the upper-level ridge, placing us closer to its
periphery under northwesterly flow. Under these kinds of setups, we
usually see more opportunities for precipitation, with higher
uncertainty in its exact timing/placement. However, with any
precipitation and subsequent cloud cover, this would aid in cooling
temperatures overall, meaning higher heat indices may not be
realized. Such is the case Sunday/Monday, with the potential for
showers/storms across the northern half of the forecast area. A good
portion of CAM guidance indicates that precipitation will remain off
towards the north and east of the forecast area during the day
Sunday, with a continued strong signal (70-90%) of heat indices
around 100-110 degF during the day in probabilistic guidance.
However, by Monday, continued disturbances within the upper-level
flow increase our potential for seeing either precipitation or cloud
cover entering the forecast area. Presently, our PoPs remain around
10-15% across northern Missouri, which reflects the lower confidence
in seeing this precise solution in the coming days. Heat headlines
remain in effect through Monday evening.

After Monday, extreme heat and humidity will begin to ease up as
winds shift out of the north with the passage of an upper level
trough and associated surface low towards the northeast. Greater
forecast deviations unfold at this point in the period, with poorer
resolution of the synoptic environment. However, the general gist of
the future forecast is increasing likelihood of shortwave
disturbances bringing PoPs back into the forecast through midweek,
with the exact timing and placement remaining uncertain at this
time.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1229 PM CDT Sat Jul 25 2026

VFR conditions prevailing at most terminals through the
forecast period. Blanket of diurnal cu has enveloped northern
MO, with KSTJ reaching MVFR ceilings through the morning.
Current thinking is that this dense area of cloud cover will not
impact downtown terminals, but will continue to monitor trend
through the afternoon. Else, expecting diurnal cu to begin
scattering out by 0z, with FEW250 prevailing afterwards. Winds
remaining generally west/southwesterly through the period at
5-10 kts, with no weather expected.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory until 8 PM CDT Monday for MOZ001>004-011>014-
     020>023-028>032-037>040-043>046-053-054.
     Heat Advisory from 1 PM Sunday to 8 PM CDT Monday for
     MOZ005>008-015>017-024-025-033.
KS...Heat Advisory until 8 PM CDT Monday for KSZ025-057-060-102>105.

&&

$$

DISCUSSION...SPG
AVIATION...SPG