St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

838
FXUS63 KEAX 160428
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1128 PM CDT Wed Jul 15 2026

.KEY MESSAGES...

- Temperatures will continue to gradually climb over the next
  several days, with highs in the middle 90s forecast this
  weekend and upper 90s on Monday.

- Showers and thunderstorms return on Thursday afternoon, with a
  30-50% chance of precipitation for areas south of Highway 36.
  These storms could pose a threat for locally heavy rainfall
  and gusty winds.

- Heat index values will reach the upper 90s to lower 100s
  Friday through this weekend, peaking around 100 to 105 degrees
  on Monday.

&&

.DISCUSSION...
Issued at 200 PM CDT Wed Jul 15 2026

Scattered showers and thunderstorms have formed across portions
of Linn County Kansas and Bates County Missouri, within an
environment characterized by very weak deep layer shear. This
precipitation has formed near a plume of deeper surface
moisture, which is slowly advecting north and west from south
central Missouri and northern Arkansas.

For tonight, expect the aforementioned scattered showers and
thunderstorms to persist through sunset. This activity is not
expected to cause any issues, outside of occasional lightning
strikes and brief heavy downpours. Thus far, any thunderstorms
have remained short lived, and this should continue into this
evening. After sunset, a loss of diurnal heating and instability
should allow for any lingering precipitation to quickly wane.

Additional showers and thunderstorms are then expected tomorrow,
as the aforementioned moist airmass overspreads much of the
area. This leads to PWATs increasing to near and just above 2",
which sits ~90th percentile climo for mid-July. Little change in
upper level flow leads to very weak deep layer shear in place
again tomorrow, and storms should have limited organization
along with slow movement. These high PWATs and slow storm
motions will pose a threat for locally heavy rainfall, and
localized flash flooding cannot be completely ruled out. Some
threat for gusty winds (wet microbursts) may exist as well,
though confidence in this is low.

Upper ridging then reestablishes further west by late week,
with the potential for more active northwest flow to establish
into early next week. This will also bring a return of
increasing low level warm advection, with guidance suggesting
low level jet development nearly each night by this weekend and
beyond. This will bring increasing temperatures across the area
by Saturday, with highs in the middle to upper 90s expected
through Monday. Monday continues to be the warmest day, where
highs in the upper 90s will overlap with dewpoints in the upper
60s/low 70s to push heat index values to as high as 100 to 105F.
The greatest heat concerns Monday are expected for areas near
and south of Interstate 70.

The less clear threat will be for any thunderstorms across the
area this weekend and into early next week. The development of
the nocturnal low level jet does suggest some threat for
overnight thunderstorms, though confidence in this remains low.
Inherited slight-chance POPs in the overnight hours Monday and
beyond look reasonable at this timeframe, and see no reason to
make any adjustments. Will especially have to monitor this
threat into early next week as troughing begins to establish
across the eastern CONUS, bringing a return of active northwest
flow aloft.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1111 PM CDT Wed Jul 15 2026

Patchy fog is possible towards sunrise in lower river valleys.
Cumulus are expected develop after 15Z, with the potential for
isolated storms after 18Z. The storms are expected to dissipate
towards sunset.

&&

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

&&

$$

DISCUSSION...McCoy
AVIATION...BT