St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

777
FXUS63 KEAX 021122
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
622 AM CDT Sun Aug 2 2026

...Updated 12z Aviation...

.KEY MESSAGES...

- Mild Weather Conditions Today

- Gradual Warm Up This Week, Gradual Increase in Humidity

- Rain Returns to the Forecast Wednesday and Thursday

&&

.DISCUSSION...
Issued at 341 AM CDT Sun Aug 2 2026

Amplified and positively tilted ridge axis currently extends from
the Rockies into the Canadian Prairie Provinces with a broad 594dam
high centered over the southwestern CONUS at the 500mb level. There
is a stronger PV anomaly off the Pacific Northwest that has resulted
troughing in the northwest CONUS, and this will eventually work to
provide more activity by the the middle of the next work week. Over
the next 24 to 36 hours, this pattern will maintain mid and upper-
level northerly flow and dominant dAVA. Strong subsidence in this
regime will continue to strengthen a broad anti-cyclone across much
of the Central CONUS. For today and Monday, temperatures will remain
in the 80s, with fairly low humidity as most of the Gulf moisture
will not have a route into the lower Missouri River Valley during
this time. Depending on how strong this surface anticyclone becomes,
we  may see a slightly stronger pressure gradient develop while the
center of it is over the Central Plains, which could give us wind
gusts at times around 15 MPH. This currently looks more favored for
Monday afternoon than it does today.

Temperatures will steadily climb back into the 90s as the week
progresses. This will be caused by a series of vort maxima emanating
from the Pacific Northwest ejecting into the northern Plains and
Canadian Prairie Provinces, that will force the ridge axis further
east, while also starting to deamplify the pattern for the Central
CONUS. This will turn flow from 850mb and below to the surface
southerly through the week, introducing a WAA regime. Current
guidance still keeps the strongest dCVA well north of the area,
which overall will limit forcing across our area. For Tuesday, low
level flow is progged to have dominant southwesterly component to it
which will push temperatures upward. By late Tuesday Night, as the
ridge axis breaks down, low-level winds back to more a southerly
component which will open up Gulf moisture transport for the lower
Missouri River Valley. As a result, humidity will begin to increase,
while temperatures still are forecast to remain in the 90s. As the
PV anomaly over the Pacific Northwest continues to send vort maxima
eastward and a trough attempts to dig into the Rockies, the Central
Plains and Midwest will start to see an upward trend of dCVA which
will attempt to generate a Lee surface cyclone across the area early
Wednesday, eventually pushing eastward into eastern Kansas and
western Missouri. With better lift present and increasing moisture,
rain showers and thunderstorm probabilities will increase Wednesday
evening through Thursday morning. Ensemble probabilities are
favoring areas north of Hwy. 36 over a 50-60 percent chance of
exceeding at 0.10 inches of QPF, though mentionable probabilities do
extend all the way southward past the Interstate 70 corridor. With
the deepening surface cyclone, notable CAPE axis does develop across
the area, and should at least prime the environment for general
thunderstorms. What is uncertain at this time, is how strong the
dCVA will be, what the H5 height gradient and associated jet stream
action will look like. This has implications for the shear profiles.
Therefore, uncertain if this will pose any kind of severe potential.
Deterministic model guidance continues to depict the better mid and
upper-level kinematic support in the northern CONUS.

For next weekend, the pattern looks rather unsettled across the area
which could lead to multiple rounds of rain showers. Currently,
ensemble probabilities for any specific time period next weekend are
fairly low, as solutions amongst individual members vary widely in
when forcing arrives. This is also leading to larger inner-quartile
spread with respect to high temperatures toward the end of the 7 day
forecast period.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 621 AM CDT Sun Aug 2 2026

High pressure will keep skies mostly clear this afternoon and
evening. Winds expected to remain under 10 kts.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...Krull