St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

291
FXUS63 KEAX 202330
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
630 PM CDT Thu Aug 20 2026

.KEY MESSAGES...

* Chance of storms building into the region Friday afternoon/evening
  from the north/northwest.

* Cooler and drier conditions through the weekend.

* Unsettled weather next week leading to periodic storm chances.

&&

.DISCUSSION...
Issued at 316 PM CDT Thu Aug 20 2026

Broad high pressure across the Upper Midwest centered near the Quad
Cities as of 18Z is expected to slowly shift towards the Tennessee
Valley. Weak return flow is expected to develop overnight, and could
see a few elevated storms develop in eastern Kansas/ southern
Nebraska overnight. This activity is expected to remain largely west
and north of the forecast area tonight, but may try to build south
during the day Friday within the northwest flow aloft.  With that
said, the cap increases in strength the further south you go, making
it increasingly difficult to get convection.  Models are highly
variable in the potential for thunderstorms tomorrow
afternoon/evening, and therefore SPC has expanded the day two
marginal across much of the area.

Shortwave embedded in northwest flow aloft located in northern
Minnesota is expected to build southeast tonight into tomorrow
towards the western Great Lakes region.  This could lead to late day
storm developing across eastern Iowa along cold front building
south. If this activity is able to develop south and west a, there
is the low potential for thunderstorms across north central
Missouri.

Light flow is expected tomorrow night into Saturday morning.  With
lack of large scale forcing across the region, it will likely be
difficult to get storms to form directly in eastern KS into northern-
central Missouri, but weak low level warm air advection across
central Nebraska into central Kansas may lead to additional storms
that may try to work into the region under the northwest flow aloft.

Upper ridge across the western US stregthens with long standing
trough across the eastern US through the weekend. Canadian high
pressure attempts to squeeze south across the central US keeping the
forecast dry and cooler than normal temperatures through the
weekend. Ridge across the west expands east but northwest flow aloft
remains leading to periodic chances of precipitation next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 629 PM CDT Thu Aug 20 2026

VFR prevailing through the remainder of the afternoon/evening at
all terminals. Winds look to remain light/variable through the
period, with indication of winds turning out of the south
towards the northwest by tomorrow afternoon. Favorable
conditions for fog development overnight under light/variable
winds and decent low-level moisture, but with building cloud
cover overnight, confidence is not high enough at downtown
terminals to include mentions of BR/FG in this TAF issuance.
Low-lying areas, such as KSTJ, may still experience dense fog
from 9-14z. Additionally, model guidance indicates the potential
for SHRA/TSRA near the end of the forecast period. However,
with continued uncertainty with these solutions, have left out
mentions of weather at this time.

&&

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

&&

$$

DISCUSSION...BT
AVIATION...SPG