St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

684
FXUS63 KEAX 252051
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
351 PM CDT Tue Aug 25 2026

.KEY MESSAGES...

- Low chance (10-20%) for showers/storms this evening/overnight.
  Primary hazards with stronger storms would be damaging winds,
  with heavy rainfall and lightning otherwise.

- Continued low chances (10-20%) for subsevere showers/storms
  tomorrow afternoon. Weather dries out through the remainder of
  the week.

- Temperatures briefly cool tomorrow, before rising through the
  remainder of the week.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 348 PM CDT Tue Aug 25 2026

Cloud debris from morning/afternoon convection continues to cover
the forecast area, helping to mitigate daytime heating and slightly
temper high temperatures during the day. Convective activity ongoing
over central Kansas is being invigorated by a shortwave trough
traversing the periphery of the upper-level ridge still parked over
the southwestern CONUS. CAMs have this activity progressing towards
the southeast through the next few hours, gradually weakening
over time. Greater consensus is that this activity will entirely
avoid our forecast area, but there are some models that hint
that we may see weakening showers/storms traversing generally
south of I-70 during the late evening. However, overall, CAMs
have become increasingly more pessimistic on the potential for
activity going into the overnight period. While there is still
ample elevated instability over our forecast area, shear is not
robust enough to increase confidence in sustained, organized
convection through the overnight period. Additionally, with
greater capping during the overnight and a lack of substantial
forcing in the synoptic and mesoscale to invigorate new
convection, there is increasing confidence in lower chances for
precipitation (10-20%) overnight into tomorrow morning. If
chances exist, they would be co-located with weakening storms
traversing eastward, generally east of I-35 and south of I-70.

An upper-level trough presently over the northern Plains will
continue digging southeast towards the Great Lakes, with its
associated cold front presently over the Dakotas sagging
southward during the day tomorrow. While guidance indicates that
storms may form along this boundary as it progresses southward,
the likelier area of development will remain towards the south
and east of the forecast area, with elevated instability beyond
a significantly capped environment appearing to inhibit
convective development during the morning and early afternoon.
If convection is able to develop, it will develop later in the
day, with areas south of I-70 having greater chances (10-20%) of
seeing subsevere showers/storms as the cold front progresses.
In the wake of the cold front, temperatures and dewpoints will
fall by a handful of degrees, maintaining seasonable
temperatures.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 348 PM CDT Tue Aug 25 2026

As the shortwave trough over the Great Lakes lifts off towards the
northeast, another trough over the Pacific Northwest will help place
the axis of the upper-level ridge over our forecast area. The
periphery of the upper-level ridge, seeing some deamplification from
the shortwaves passing to the north, will remain north of the
forecast area, keeping PoPs low through the remainder of the week.
By the weekend, with greater southerly flow on the western edge of
surface high pressure, coupled with enhanced WAA from southwesterly
flow aloft, heat and humidity look to rise enough to have heat
indices break the triple digits south of the US-50 corridor.
However, overall chances for this happening remain lower (15-20%),
so future forecasts will have to monitor this trend to see if it
maintains.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1238 PM CDT Tue Aug 25 2026

Southern terminals will be VFR through the forecast period. Fog
is possible for northern terminals including KSTJ and
visibility has a 25% chance of dropping to less than 1 mile
around sunrise. Winds will be light out of the east until late
morning when winds will pick up out of the north/northwest.

&&

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

&&

$$

SHORT TERM...SPG
LONG TERM...SPG
AVIATION...IPC