St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

159
FXUS63 KEAX 250808
AFDEAX

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

.KEY MESSAGES...

- Hazardous heat returns to the area. Heat index values of
  100-110 degrees are anticipated with the higher values being
  south of the MO River today. 105-110 Heat index values are
  expected for Sunday.

- The hot and humid weather pattern remains consistent through
  Monday; however, some small chances for overnight convection
  early Monday and Tuesday add a bit of uncertainty.

- Slightly less hot conditions are expected later this week.

&&

.DISCUSSION...
Issued at 306 AM CDT Sat Jul 25 2026

Friday`s feature presentation was widespread light rainfall with
embedded heavy downpours. That changes for Saturday as ridging builds
across the Rocky Mountains returning hazardous heat to the region.
Satellite imagery shows this expansive high pressure building across
the eastern Rockies. This high dominate the weather pattern for much
of the coming week.

Eastern Kansas and western MO find itself in the eastern quadrant of
the high. This yield upper level northwesterly flow which one would
traditionally think would tamper heat expectations. Unfortunately,
low level flow remains southerly continuing to advect warm air and
moisture into the region. This advection over the previous few days
have established a warm and muggy environment to base Saturday`s
heat. As of midnight, the dew point at MCI sits at 73 degrees which
yields a fairly soupy overnight. Low clouds continue to reside over
the region; however, upper air analysis shows ridging building
across the 850mb level which is expected to clear clouds out,
especially once solar heating begins after sunrise. Heat is boosted
by SSW flow lifting temperatures into  mid to upper 90s. With base
dew points averaging in the low to mid 70s, heat index values look
to quickly increase into the triple digits. Ensemble guidance
suggests a 30-50 percent chance of dew points exceeding 80 degrees
across southern and central MO. Heat index values of 105-110 degrees
are likely with isolated spots of 115 degrees possible in that
region with most other seeing values in excess of 100 degrees.
Sunday, the hazardous heat becomes more widespread as the axis of
low level warm air advection expands. Much of the region is expected
to see heat index values of 105-110 degrees. Dew points once again
look to reach near 80 degrees across much of the region making it
feel oppressively muggy. Overnight lows in the mid to upper 70s
bring little relief from the daytime heat. Hazardous heat continues
Monday were once again heat index values of 100-110 are possible.

There are some uncertainties with heat index values Sunday through
Tuesday. Ridging across the CONUS during the summer oftentimes
results in thunderstorm complexes running around the periphery of the
ridge (mainly during the overnight) which can play havoc on daily
temperature forecasts. Some models are suggesting the potential for
a few of these thunderstorm complexes moving through the area which
could affect the temperature outlook. However, general consensus
across model members maintains the hazardous heat through the
period. Higher confidence lies within the consensus as the placement
of the high across the Rockies with generally NW flow is less
suitable for moisture transport. The most likely facilitator of
moisture in this synoptic configuration is the west coast which most
of the water would be orographically squeezed out as it transits the
Rockies.

Long range guidance suggest that some embedded upper level
shortwaves may encourage the development of mid to low level lee
troughs which look to disrupt the low level flow tipping the scales
in favor of drier air working its way into the region. Highs tamper
slightly back to the low 90s, but dew points fall significantly to
around 70 degrees; although, it will still feel quite unpleasant.
This will lower heat index expectations to around 100 which will
feel relatively better than the 110 from earlier in the week.
Precipitation chances remain present, especially late week, but
model solutions remain quite divergent in timing and
probabilities.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1100 PM CDT Fri Jul 24 2026

CIGs are expected to continue improving to VFR overnight. For
the 06Z issuance, KMCI, KMKC, and KIXD were allowed prevailing
VFR conditions to kick off the TAF period while KSTJ will remain
MVFR for the first few hours. A cluttered cloud deck will
continue sliding east overnight; as it does so, brief and
transient reductions to MVFR CIGs will be possible. There is a
low (~20%) chance of fog across north-central and northeastern
Missouri overnight and into early Saturday
morning...probabilities are much lower within the corridor of
terminals but the potential will need to continue to be
monitored.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory from 1 PM this afternoon to 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 from 1 PM this afternoon to 8 PM CDT Monday for
     KSZ025-057-060-102>105.

&&

$$

DISCUSSION...Pesel
AVIATION...Macko