St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

869
FXUS63 KEAX 131711
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1211 PM CDT Wed May 13 2026

.KEY MESSAGES...

- A few showers and storms possible Thursday morning. These will
  be non-severe. A better chance for strong to severe storms
  will exist late Thursday evening into the overnight.

- Much warmer and more humid conditions Friday and through the
  weekend.

- Multiple chances for strong to severe storms Friday and into
  weekend. Friday, particularly, could feature large hail and
  damaging winds with storms that develop during the afternoon.

&&

.DISCUSSION...
Issued at 246 AM CDT Wed May 13 2026

Quiet weather today with a cooler and drier airmass, associated with
a surface high pressure area moving into the region behind a cold
front that moved through Tuesday evening. That high pressure area
will shift to the Mid-Mississippi Valley by tomorrow morning, with
southerly flow increasing to our west. Isentropic ascent, notable
from 305K to 310K will develop over eastern KS before sunrise
Thursday and shift east through the morning hours. Forecast
soundings show some elevated instability is present, based on
parcels lifting from around 7500 ft and higher. This ascent and
weak, elevated instability may lead to isolated to scattered showers
and a few thunderstorms Thursday morning. No severe weather is
expected given the elevated nature and weak overall instability.

More widespread storms, with better chances for strong to severe
storms, will develop late Thursday evening and overnight. A subtle
mid-level shortwave trough will move into the Central Plains during
the day and track east through the day. Warm/ moist advection ahead
of the shortwave will help dewpoint climb into the upper 50s to
lower 60s. This will lead to moderate to strong instability across
central to eastern KS during the day. Storms should develop in
central KS along a boundary as the mid-level wave moves into the
area. These storms may then congeal into a convective system as the
shortwave progresses eastward with time during the evening and
overnight hours. Instability weakens with eastward extent so
overall, the storms should be trending weaker. But there may still
be a threat of strong to severe storms, with mainly a damaging wind
threat, as the system moves east.

Friday and through the weekend continue to look warm and humid. Have
continued to pull the throttle back on high temperatures Friday and
think that upper 80s to near 90 degree values look more reasonable
given low-level thickness values. The increasingly warm and more
humid conditions will lead to stronger instability building each day
though. Looking through forecast soundings, especially Friday, there
is minimal to no inhibition during peak heating. Given the potential
for strong to extreme instability to build, with minimal inhibition,
and modest 0-6km shear, severe storms look possible. Large hail and
damaging winds look possible. Severe weather potential continues to
look possible, mainly to the west of the area Saturday and
especially Sunday. As mentioned in the previous discussion, if
storms can organize into a convective system, there may be a risk of
severe weather Saturday and Sunday night. There`s so much
uncertainty though given the small-scale details that are not
resolvable at this point. But given it`s over the weekend, being
weather aware and keeping track of the latest forecast will be
crucial.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1209 PM CDT Wed May 13 2026

VFR condition through the period. Surface ridge axis is expected
to shift east this afternoon, leading to northerly winds
transitioning from the southeast this evening. Winds will
increase and become gusty Thursday as low pressure approaches
from the west.

&&

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

&&

$$

DISCUSSION...CDB

AVIATION...BT