St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

948
FXUS63 KEAX 091700
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1200 PM CDT Thu Jul 9 2026

.KEY MESSAGES...

- Thunderstorms Expected Overnight; Heavy Rainfall Possible

- Conditional Severe Threat Thursday Afternoon; Activity May
  Push Further Eastward

- Near Triple Digit Heat Index Values Interstate 70 and South
  Thursday

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 1121 PM CDT Wed Jul 8 2026

H5 short-wave trough is moving out of the eastern Plains into the
lower Missouri Valley. Stronger surface cyclone is present over
western Kansas. This will be slow to move as it is largely
disconnected from any mid-level steering flow. This has setup a warm
front that as of late Wednesday evening is currently stalled over
eastern Kansas. Convection over the past several hours has resulted
in a differential heating boundary from the Upper Midwest into the
Sandhills of Nebraska, and has been able to develop some new
convection heading into the overnight hours. Complicating the
mesoscale view though are numerous outflow boundaries that have
developed under the area upper-level divergence. Broad large-scale
ascent should continue to occur as this short-wave trough move overs
head, and shower/storm activity should continue overnight and
through much of the morning. While there is decent CAPE ahead of
these showers/storms moving in, the weaker mid-level flow away from
the axis of the short-wave trough, keeping deep layer shear low, has
struggled to sustain strong updrafts for an extended period of time,
with most storms becoming outflow dominant in fairly short order. A
few stronger cores may be possible overnight with any remaining
pockets of higher CAPE, and perhaps a few isolated wind gusts around
60 MPH and or quarter-size hail may be possible with a few storms.
Most of this activity will push eastward out of the forecast area
before 18z. Depending on how organized activity remains, PWAT values
near 2.0 inches along with deep warm-cloud processes, efficient
rainfall may result in localized rainfall amounts between 1.5 and
2.0 inches, and therefore may present some hydrologic issues,
including the KC metro.

Redevelopment east of Interstate 35 is possible later into the
afternoon and evening, depending on where the boundary ends up. If
outflow boundary production from overnight convection lingers, this
may greatly alter the mesoscale environment heading into the
afternoon. We may see more mid-level short-wave activity in the
afternoon which could increase lift across much of the area again.
However, the stronger vort maxima may move further eastward out of
the area before there is sufficient time for the boundary layer to
destabilize. And depending on where subsequent mid-level short-wave
travel, may have localized pockets of deep layer shear to help
organize convection. But if cloud-cover lingers into the middle of
the afternoon across the area, this may push convection initiation
further eastward or may require new activity to travel further
before encountering a higher CAPE environment to strengthen.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 1121 PM CDT Wed Jul 8 2026

Friday - Sunday...

Ridging will begin to build over the western Plains on Friday.
Remnant troughing to slowly push eastward Friday into Saturday. A
stalled frontal boundary will remain parked over the region during
this time. Southerly flow south of the front will continue to pump
moisture into the region as PWATs will remain in the 1.5-1.75 inches
range. This moisture and lifting mechanisms will keep scattered
showers and storms in the forecast for Friday through most of
Sunday. Over the southern half of the forecast area (south of the
stalled front), we will see SBCAPE increase, which will allow for a
small chance for strong storms. Main hazard with this will be gusty
to damaging winds, small hail, and heavy rainfall.

During this time, we will see highs in the upper 80s and low 90s and
lows in the upper 60s and low 70s.


Monday - Mid Next Week...

By next week, impressive ridging will build over the central CONUS
and high pressure will strengthen at the surface. These features
will allow for conditions to dry out and for temperatures to
increase a bit each day. Temperatures are likely to top out in the
low to mid 90s mid next week. Though, dew points will remain in the
mid 60s, which will keep heat indices in the upper 90s. Winds will
remain light through this timeframe.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1200 PM CDT Thu Jul 9 2026

Thunderstorms are expected to redevelop this afternoon, though
there is uncertainty in where exactly these develop. Given the
uncertainty in the placement of storms, have kept as prob30
across all sites. Storms end after 00z with winds becoming light
and variable in direction. Additional showers are expected on
Friday morning across all sites.

&&

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

&&

$$

SHORT TERM...Krull
LONG TERM...Wilson
AVIATION...Hagenhoff