St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

954
FXUS63 KEAX 031715
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1215 PM CDT Fri Jul 3 2026

.KEY MESSAGES...

- Hot and humid conditions continue through the weekend. The
  Extreme Heat Warning was extended through Saturday for
  counties along and south of the Missouri River, with a Heat
  Advisory on Saturday for northern Missouri.

- Chance of storms (50-70%) overnight tonight. Severe chances
  are low, but should storms strengthen then hail and wind are
  the main hazards.

- Additional scattered thunderstorms are expected to develop
  Saturday afternoon/evening and into the overnight. Hail and
  wind are the primary concerns, along with pockets of heavy
  rain.

&&

.DISCUSSION...
Issued at 507 AM CDT Fri Jul 3 2026

Presently, the upper-level ridge that has been the driver of
our dangerous heat this past week continues sliding off to the
east. Impulses traversing the upper-level flow continue to
dampen its effects over our area, and will leave us open for
several opportunities for showers/storms in the coming days.
Overnight, a complex of storms over central Iowa has slowly
pushed southward, but has effectively remained stationary due to
weak northerly upwind propagation contesting with opposing flow
out of the south/southwest. As these storms have remained
mostly stationary, our area has remained rain-free through the
night. The latest CAM guidance pushes a bulk of this activity
off towards the north and east through the remainder of the
overnight into the morning as activity weakens and begins to
follow southwesterly flow around the upper-level ridge. However,
some low chances (15-30%) exist for precipitation to reach far
northern Missouri through the morning hours along outflow
boundaries. These storms are expected to remain nonsevere, as
activity remains elevated and overall organization of storms
remains poor with lower effective shear.

Dangerous heat will continue to be a concern through the day today,
with heat indices between 100-110 degF owing to continued warm,
moist flow out of the south/southwest as the ridge takes its time
meandering off to the east. However, unlike the previous few days of
oppressive heat with no precipitation, chances for precipitation (50-
70%) return this evening/overnight. A shortwave ejecting off the
Rockies will prompt the development of an MCS that will traverse the
central Plains. However, confidence in the exact timing and
placement of this activity is not high. CAMs are scattered with
their resolutions of convective activity, and recent runs have not
made this picture any clearer with a lack of consistency with
earlier simulations. As it stands, a bulk of this forecast will rely
on real-time environmental analysis, consideration of which models
initialize the environment the best ahead of activity, and watching
for eventual convergence on solutions. What is known regarding this
event is that there will be a potent amount of instability in place,
with ~3000-4000 J/kg of MUCAPE to work with, and steep low/mid-level
lapse rates that will prompt a threat for severe wind/hail. Adequate
bulk shear around 30-40 kts will help promote organized convection,
which increases concerns for severe potential. Confidence is still
highest in the greatest potential for activity remaining in the late
evening/overnight period, with CAMs isolating activity to
around/after midnight. With high PWAT values and deep warm cloud
layer depths, excessive rainfall and hydrological issues are a
concern with activity alongside severe potential, especially if any
activity stalls out through the night and prolongs rainfall over a
specific area.

Previous convective activity will help dictate where "cooler"
temperatures Saturday will reside. Northern Missouri will see lower
apparent temperatures relative to previous days, while much of
central/southern Missouri will still be under oppressive heat
indices in the triple digits. As such, heat headlines split to
represent this difference between advisory and extreme heat
criteria. Saturday will still have opportunity for convective
activity through the day, with high MUCAPE ~4000-5000 J/kg building
during the day. The focal point of forcing for this day appears to
be off of a boundary draping down from the previous day`s shortwave
as it traverses off towards the Great Lakes. Like the previous day,
greater potential for precipitation appears during the late
evening/overnight along a stronger trough axis, with scattered
activity during the afternoon. With this activity, effective bulk
shear around 25-30 kts implies that activity, while having the
potential to organize, may not be as robust as the previous day`s
activity. However, with adequate mid-level lapse rates, any robust
storms that are able to develop will carry a risk for wind/hail. As
the forecast continues to evolve going into the weekend, remain
weather aware, especially if you are planning any activities...

Residual activity on Sunday is expected to clear out through the day
as amplified ridging builds over the area going into next week.
Under semi-zonal flow, some uncertainty exists with the exact
details regarding the overall evolution of the synoptic profile
through the week. Perturbations in the upper-level flow could lead
to a wetter pattern, while stronger ridging could keep us within our
hot pattern for the forseeable future. At present, more synoptic
guidance is hinting at a drier, warmer forecast through the first
half of the week... Future forecast iterations will have to observe
this trend to see if it holds.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1215 PM CDT Fri Jul 3 2026

A line of convection from northwest Missouri into east central
Kansas has moved slowly east this morning and reach KSTJ around
midday. The line is expected to continue east through the early
afternoon with -TSRA at KMCI/KMKC. The line is slowly moving ENE
and at this time expect impacts to remain north of KIXD. After
a lull in activity additional thunderstorms will move from NW to
SE across Missouri overnight and early Saturday morning with
thunderstorm impacts likely across all sites.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 8 PM CDT Saturday for MOZ028>033-
     037>040-043>046-053-054.
     Extreme Heat Warning until 9 PM CDT this evening for
     MOZ001>008-011>017-020>025.
     Heat Advisory from 9 PM this evening to 8 PM CDT Saturday for
     MOZ001>008-011>017-020>025.
KS...Extreme Heat Warning until 8 PM CDT Saturday for KSZ025-057-
     060-103>105.
     Extreme Heat Warning until 9 PM CDT this evening for KSZ102.
     Heat Advisory from 9 PM this evening to 8 PM CDT Saturday for
     KSZ102.

&&

$$

DISCUSSION...SPG
AVIATION...Hagenhoff