St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

330
FXUS63 KEAX 262307
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
607 PM CDT Sun Jul 26 2026

.KEY MESSAGES...

- Hazardous heat continues through Tuesday morning, with heat
  indices around 105-115 degF during the daytime and overnight
  lows in the 70s. Low confidence in showers/storms across
  northern Missouri, which could impact heat and humidity.

- Temperatures and heat index values lower through the week,
  with higher heat indices remaining near 100 degF towards
  southwestern MO/southeastern KS.

- Increasing chances (50-70%) for precipitation by the end of
  the week, some uncertainty remains in exact timing/placement
  of greatest potential.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 334 PM CDT Sun Jul 26 2026

Hazardous heat continues through this afternoon. Taking a look at
the synoptic scale, a stout low-level shortwave has centered itself
across the forecast area, coupled with the continued presence of an
upper-level ridge over the western CONUS. Although the positioning
of these features would prompt the advection of drier air across the
area from the west/northwest, and our dewpoints have overall
remained slightly lower than yesterday to reflect that, these
features have also assisted in keeping skies clear under large scale
subsidence. This has warranted ambient air temperatures to soar near
the triple digits going into the afternoon, with heat indices
similarly jumping to as high as 110+ degF for much of the area.
Parts of northwestern MO have seen heat indices skyrocket towards
120+ degF, which can be attributed to higher dewpoints as a result
of increased moisture released into the atmosphere from crops.

A shortwave trough presently centered over the northern Plains is
forecast to continue traversing eastward through the evening and
overnight, helping to push the shortwave ridge off towards the east
into tomorrow morning. With this shortwave, there is an associated
risk for showers/storms going into the evening/overnight, which
could reach as far as north/northeastern MO. Recent guidance has
placed this feature further north relative to RAP Mesoanalysis,
which could have implications on their ability to properly resolve
where and when precipitation will occur over the forecast area
tonight through Monday. This is seen with variability in model
solutions on precipitation in the near term. Some guidance pushes
convection further into northern MO through the morning and clears
it out by the afternoon, develops convection through the day
tomorrow, or keeps a bulk of the activity off to our northeast.
Regardless of solution, overall probabilities for seeing
precipitation remain low (10-15%). Lingering cloud cover from any
activity could continue to impact temperatures depending on their
extent and density, but (as was seen this morning) this cloud cover
could be sparse enough that it does not impact rising heat and
humidity. Additionally, probabilistic guidance like the HREF
continues to indicate high probabilities (70-90%) of heat indices
exceeding 110 degF tomorrow with continued high ambient temperatures
near the triple digits and dewpoints around the mid 70s for much of
the area. With these factors in mind, have elected to extend the
Extreme Heat Warning through the day tomorrow. A different shortwave
trough digging from the northern Plains into the Great Lakes will
drape a boundary across the central CONUS, which will push southward
Monday night into Tuesday morning. There is some variation on the
impacts of this boundary on the forecast area, with a greater bulk
of guidance indicating that the boundary will push across the
forecast area and slightly dampen down temperatures/dewpoints going
into Tuesday and lowering overall heat indices. As such, the Extreme
Heat Warning was only extended out to Tuesday morning, with further
analysis of this trend being needed in subsequent forecast
cycles.

&&

.LONG TERM /MONDAY THROUGH SUNDAY/...
Issued at 334 PM CDT Sun Jul 26 2026

After Tuesday, synoptic guidance indicates that the upper-level
ridge will persist over the western half of the CONUS with
increasingly blocked flow behind a closed low developing over the
East Coast. Embedded shortwaves in the low-level flow towards the
west will increase PoPs through midweek, before a stronger impulse
from the upper-level trough off the PNW Coast prompts the recession
of the ridge off towards the west. This impulse in the upper-level
flow is projected to dig southeastward, impacting the forecast area
by the end of the period. There is continued variance in long term
solutions on the exact timing and placement of this feature, but
this variance is lessening with subsequent forecast cycles, so
greater confidence may be ascertained in this solution. However,
considering how far in the future this forecast resides, this trend
will need to continue being monitored.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 605 PM CDT Sun Jul 26 2026

VFR conditions are expected to prevail with southerly winds.
There is a low chance of an isolated storm, but confidence in
timing/location is uncertain so left mention out of the
terminals for the time being.


&&

.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.

&&

$$

DISCUSSION...SPG

AVIATION...BT