St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

601
FXUS63 KEAX 272312
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
612 PM CDT Mon Jul 27 2026

.KEY MESSAGES...

- Hazardous heat continues through the day, with
  isolated/scattered showers/storms across northern Missouri.

- Additional chances for precipitation through the next two days
  (15-30%), with some remaining uncertainty on timing/placement
  of activity tomorrow.

- Continued signal for storm system impacting overnight Thursday
  into Friday. Forecast remains dry through remainder of period.


&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 401 PM CDT Mon Jul 27 2026

Hazardous heat remains a concern through the rest of today and
tonight. Clearing skies in the wake of sparse cloud cover from
remnant overnight activity has once again allowed ambient air
temperatures to climb near the triple digits during the afternoon,
with dewpoints remaining in the low/mid 70s across much of the
forecast area. Heat indices have similarly climbed past the triple
digits through the afternoon, with some observation sites reporting
heat indices at/above 110 degF as the afternoon progresses. Ambient
air temperatures will continue to climb for much of the area through
the remainder of the afternoon with greater daytime heating under
clear skies.

The only area that has the opportunity to stay below
extreme heat warning criteria for the remainder of the day would be
far northern MO, as showers/thunderstorms over south-central IA have
generated a plume of cloud cover across much of that area. Overall
storm motion with these storms has remained slow and southeasterly,
with much of the activity weakening as it reaches the IA/MO border.
Much of this has to do with the less favorable environment for
continued thunderstorm development, with greater capping and less
synoptic scale ascent separated from the boundary currently present
over central IA. However, with favorable effective bulk shear ~30
kts and plenty of instability to tap into (~4500-5000 J/kg),
elevated showers/storms still have the potential to produce strong
winds and up to severe hail with the strongest storms. However, this
potential remains low, with greater confidence in storms continuing
to weaken as they traverse southeast away from better synoptic scale
ascent.

Going into tonight, a weak boundary extending off a surface low
presently situated over the western Great Lakes will push down from
the north. As this boundary pushes through, advection of
(relatively) cooler, drier air will take temperatures/dewpoints down
by a few degrees, taking us out of our triple digit heat indices.
Relative to the previous forecast, guidance has increasingly
converged on the strongest push of the boundary occurring further
east. Thus, the boundary`s entrance into our forecast area looks to
be closer to tomorrow morning. As it pushes downward, there is some
opportunity for precipitation to develop along its leading edge.
However, the greater opportunity for precipitation will come along a
weak shortwave trough riding the periphery of the receding upper-
level ridge. There is some disagreement on timing with recent CAM
runs, with some guidance indicating storms will enter by the morning
while others hold it off through early afternoon. Regardless, there
is increasing confidence in the potential for showers/storms
tomorrow afternoon. The greatest corridor for stronger activity
remains out ahead of the boundary with greater MUCAPE as it sags
southward, but marginal shear profiles and poor lapse rates lowers
confidence in the potential for stronger thunderstorms with activity
tomorrow. With this increasing precipitation potential, and
considering building cloud cover along with the presence of the
boundary, have held off on further issuance of heat headlines across
central MO. However, there is still an opportunity for areas in the
southern part of the CWA to see heat indices climb near advisory
criteria during the day (20-40%) in advance of any clouds/rain.

&&

.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 401 PM CDT Mon Jul 27 2026

For the remainder of the week, as the upper-level ridge continues
receding eastward with amplified ridging setting up over the Great
Lakes area and a shortwave ridge centered over the Mississippi River
Valley, the forecast area will remain along the periphery of the
atmospheric flow and see impacts from shortwave disturbances riding
that flow. These impacts look to primarily be overnight, with
Tuesday evening/Wednesday morning looking to be the onset of this
"ridge rider" activity (30-50% PoPs). Wednesday evening into
Thursday looks to be much the same, before a deepening upper-level
trough digs down from the northern Plains Thursday night into
Friday. For those who have been following along at home, this
feature has been consistent through several forecast cycles.
However, unlike previous cycles, there is greater agreement between
synoptic guidance on the placement of this upper-level trough. The
implication for our forecast area would be greater confidence in a
boundary draped through the central CONUS invigorating chances for
precipitation (50-70%) Thursday evening into Friday morning.
Although specific details this far out are still not certain enough
for a definitive statement on impacts, subsequent forecast cycles
will have to monitor trends to evaluate if there is an associated
severe/hydro threat with this activity. At present, there is a
consistent, strong signal for this system to impact us by the end of
the week. After the passage of this trough, upper-level ridging
looks to build back in relatively quick, drying out the remainder of
the forecast period.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 608 PM CDT Mon Jul 27 2026

Spotty showers across northern Missouri are expected to fall
apart this evening. Weak boundary is expected to sag southward
tonight, and there could be additional storms building in from
the west after 12Z/Tuesday. Hard to pin point timing at this
point, but tried to concentrate a prob30 in the most likely
window for each of the terminals.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 7 AM CDT Tuesday for MOZ001>008-
     011>017-020>025-028>033-037>040-043>046-053-054.
KS...Extreme Heat Warning until 7 AM CDT Tuesday for KSZ025-057-060-
     102>105.

&&

$$

SHORT TERM...SPG
LONG TERM...SPG
AVIATION...BT