St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

504
FXUS63 KEAX 291124
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
624 AM CDT Wed Jul 29 2026

.KEY MESSAGES...

- Muggy conditions continue today and heat index values once
  again approach 100F for most.

- Scattered showers and thunderstorms are possible this morning
  (10- 20%) along and west of the MO/KS state line. More rain
  is possible this afternoon and evening (10-20%). Pulse like
  storms with localized heavy downpours possible. No severe
  weather is anticipated.

- Thunderstorms chances expand Thursday especially during the
  afternoon through overnight (30% AM to 70% PM). Once again
  heavy downpours are expected with marginal strong to severe
  storm chances.

- Cooler conditions are expected to move in Saturday (low to mid
  80s) with temperatures warming back toward seasonal normals
  (90s) next week.

&&

.DISCUSSION...
Issued at 254 AM CDT Wed Jul 29 2026

Never underestimate the power of warm air advection, and apparently,
the same goes for moisture advection. Obs Tuesday showed dew points
toping 80 degrees in several areas in part because a boundary from
Tuesday morning convection regressed a little further northward than
initially anticipated. Showers and cloud cover also dissipated
slightly faster opening up the opportunity for temperatures to warm
slightly higher, especially across far northern MO.

The overall weather pattern remains consistent with what we have
seen the past few days. Satellite and 500mb analysis show the
eastern quadrants of the ridge centered over northern NM have
retreated further west. This has opened up the flow for shortwaves
across the area as well as displace potential ridge running
thunderstorm complexes more westward. A surface high descending from
east central Canada across the region works to keep these waves west
of the area overnight although some models have been extending
precipitation chances are far east as the MO/KS state line early
this morning; therefore, have kept a few PoPs across the far west of
the area. Some storms have formed over NE KS as of writing and we
will have to continue monitoring them and the environment to see how
they evolve through the early morning hours. Additional shortwaves
are expected later this afternoon and evening which may initiate
some isolated to scattered showers and thunderstorms. Placement of
these storms remains a little uncertain as they are expected to be
more pulse like in nature. Models scatter these showers across the
area, but most show higher probabilities in far NW MO. However, if
the high is able to build in more substantially, chances for showers
and storms later today lessen.

Chances for showers and storms increase through the day Thursday as
the gradient between a leeward low in western KS and a surface high
across the southern Great Lakes compresses. This entices low level
convergence and lift leading to the more widespread showers and
storms. Convective variable remain rather muted at this time
limiting concerns for strong to severe storms, but instability of
~2000 J/kg with bulk shear around 25 knots does present a marginal
risk for a strong to severe storm.

As the weekend approaches, a substantial shortwave trough descends
from interior Canada and looks to bring greater chances for showers
and storms as well as cooler conditions across the area.
Acceleration of low level flow ahead of the trough quickly pushes
warm air and moisture into the region. This pushes PWAT values up to
1.5 to 2 inches which presents and environment favorable for heavy
rainfall. Large scale instability and lapse rates are somewhat
limited curtailing much of the strong to severe concerns at this
time. As storms depart Friday evening, cooler air pushes in behind
and highs Saturday only reach the low to mid 80s. Early next week
another ridge settles in across the Great Lakes which pushes
temperatures back upward toward seasonal normals. Extended guidance
shows the synoptic ridges across the southern CONUS weakening
enabling the northern jet stream to sag southward potentially
bringing a more dynamic pattern further south into the CONUS.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 620 AM CDT Wed Jul 29 2026

VFR conditions are expected through the vast majority of the
period. Isolated SHRA is possible south of I-70 across KS this
AM with most activity staying west. Additional SHRA/TSRA is
possible later this afternoon and evening, but coverage is
expected to be very isolated. There remains much uncertainty on
where storms may develop.

Winds remain generally out of the SE before becoming more
southerly late. There is likely to be some haze from smoke aloft
outside of storms, no surface FU impacts are anticipated.

&&

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

&&

$$

DISCUSSION...Pesel
AVIATION...Pesel