St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

403
FXUS63 KEAX 281126
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
626 AM CDT Tue Jul 28 2026

.KEY MESSAGES...

- Scattered showers and thunderstorms this morning across
  eastern KS and far western MO as a thunderstorm complex moves
  through the area.

- Heat expectations are lowered today. Heat index values around
  100F anticipated; however, morning shower activity may affect
  potential heat.

- Warm and active pattern continues through the week culminating
  in a significant pattern shift and cooldown this weekend.

&&

.DISCUSSION...
Issued at 245 AM CDT Tue Jul 28 2026

Another warm and soupy night out there with temperatures around the
area in the 80s. For those in downtown KC, the urban heat island has
kept the 90s around through midnight. Temperatures do continue to
descend through the night; however, they are only expected to bottom
out in the low to mid 70s. The good news is the temperature trend
through the week is downward, not a very steep downward, but down
nonetheless. Also the pattern becomes more active introducing
opportunities for showers and thunderstorms which will create rapid
localized cooling followed by immediate swampy conditions behind the
rain (for any daytime storms).

Satellite imagery and H500 analysis shows the resident high
continuing to sit over the Rocky Mountains; however, the eastward
extent has waned and become less stout. This facilitates more
shortwave perturbations progressing over the area and bringing
multiple potential rounds of precipitation over the next several
days.

The first looks to arrive this morning as a large thunderstorm
complex maneuvers its way across SE Nebraska and northern KS. Short
range guidance suggests this complex makes its way toward the KC
metro and points south through the morning hours. This is supported
by 1000mb-500mb thickness lines as well as elevated CAPE gradients.
Additional details from Corfidi vectors suggest storms will
propagate eastward then dive southward as they enter western MO
potentially making it all the way to the Ozarks as they decay
towards sunrise. There are several complications in the short term
forecast primarily some residual boundaries from large scale activity
to the east and potential weak frontogenesis across the area as the
MCS approaches. These uncertainties will likely affect the strength
and propagation of convection with consensus leaning toward overall
weakening.

Regardless of the presence of storms, the residual cloud cover is
likely to tamper the heat a bit across the area. NW flow establishes
across mid levels and above advecting relatively cooler and drier
air into much of the region. High temperatures only reach the upper
80s to 90s with heat index values around 100F. Unfortunately for
those towards to the I-44 corridor, heat index values remain near
100-105F (advisory level); however, there is a potential that the
MCS mentioned earlier will reach to that region resetting heat
expectations. It is prudent to see how far storms may propagate in
the effort to issue a more confident heat product. Additionally,
further shortwaves are expected to transit the area today which may
spark further convection later this afternoon and evening, although
coverage looks more favorable over the Ozarks than Central MO.

This pattern looks to continue through the rest of the week. The
good new is this means the decreasing temperatures trend continues
with highs lowering into the low 90s and heat indices settle around
or below 100F. The ridge continues its hold over the Rockies and
upper level shortwaves continue to flow over the region. Chances for
pop up showers and storms as well as development of nocturnal
thunderstorms complexes continues. The subtle interactions of
boundaries and mesoscale front make forecasting these systems
somewhat difficult on more course deterministic models. Consensus so
far forms these systems outside of the region and advances them into
our area leaving local storm development to more pulse like pop-up
storms.

Deterministic guidance suggests a larger scale change late week as a
deep trough is expected to dig out of interior Canada across the
eastern Plains. This presents the most substantial chances of
convection Friday and Saturday. Some uncertainties remain as small
deviations in the early track will result in larger scale variances
in extended hour guidance. However, there is higher confidence that
this will significantly cool conditions with early forecast highs
in the low to mid 80s.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 622 AM CDT Tue Jul 28 2026

RA prevails at the TAF sites and persists through much of the
morning. Winds become light and VRB behind the RA with high BKN
to OVC skies through the period. Additional SHRA/TSRA
is possible later this afternoon and overnight, but remains
east and south of the terminals.

&&

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

&&

$$

DISCUSSION...Pesel
AVIATION...Pesel