St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

412
FXUS63 KEAX 302328
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
628 PM CDT Tue Jun 30 2026

.KEY MESSAGES...

* Hazardous heat threat continues. An Extreme Heat Warning will
  remain in effect through 9 PM Friday evening.

* Most areas to remain dry throughout the week. There is a
  chance (15-30%) for precipitation across northern/northwestern
  Missouri during the week.

* Shower/storm chances (30-50%) return by Saturday evening.

&&

.DISCUSSION...
Issued at 333 PM CDT Tue Jun 30 2026

DISCUSSION:

At present, a 592 dm ridge situated over the Ohio River Valley is
contributing to continued dangerous heat areawide, with
southerly/southwesterly winds advected warm, moist air through the
central CONUS and keeping heat indices within the triple digits.
Synoptic guidance is continuing to indicate this ridge being nudged
over to the east as a result of a closed low lifting across the
northern CONUS, which could aid in lessening the ridge`s
oppressively hot influence over the northern half of our forecast
area. However, as the ridge continues sliding off to the east, a
deep trough persisting over the western CONUS will enhance deep
south/southwesterly geostrophic flow over our area. This will aid in
the continued transport of warm, moist air over our area, which will
continue dangerous heat and humidity. As such, with the potential
for continued heat indices at/near advisory criteria over an
extended period of time, the Excessive Heat Warning will remain in
effect through Friday evening. However, with the synoptic pattern
that is materializing, there may be a need to update headlines for
our northern row of counties regarding heat. Probabilistic guidance
is continuing to indicate that dewpoints and temperatures will back
off across northern Missouri in the next day or two, possibly owing
to the simulation of more progressive boundaries in line with
surface low pressures developing off of shortwave disturbances in
the upper-level flow. With these boundaries/shortwaves, there is an
an associated risk for showers/storms across northern/northwestern
Missouri on Wednesday evening into Thursday morning, and again
Thursday evening into Friday morning. However, with continued
synoptic-scale subsidence as the ridge`s influence persists over our
area, the probability of these showers/storms having an appreciable
effect on our forecast area is low. Thus, with subsequent forecasts,
the exact scale and impact of this trend will need to be evaluated
in further detail to determine whether or not headlines will need to
be updated accordingly.

Regarding the weekend... By Friday, the upper-level ridge will have
slid over towards the East Coast and deamplified under continued
assault from shortwaves ejecting off the Rockies. With this, the
overall risk for hazardous heat is expected to decrease as
atmospheric winds gradually shift out of the west/northwest.
However, there is some signal from probabilistic guidance that
hazardous heat will continue into Saturday, with the LREF showing 30-
50% probabilities of exceeding triple digit heat indices under
ongoing southerly flow at the low-levels. Now, whether this warrants
an extension in current heat headlines is still under review, as
confidence in this solution is not high at the time. The potential
for showers/storms on Saturday also owes to decreased confidence in
continued hazardous heat through the weekend. So, as was the case in
the previous paragraph, future forecast iterations will need to
analyze this trend to determine how it will impact heat headlines.
Saturday evening, the greatest chances for precipitation follow
along with another disturbance in the upper-level flow. Severe
potential still looks to remain marginal with this activity, with
poor shear despite ample CAPE and activity looking more elevated
through the overnight period. Closing out the forecast period,
ridging appears to build over the western third of the CONUS, with
some continued opportunity for scattered PoPs with disturbances in
the upper flow. However, due to the uncertainty of the forecast that
far ahead in time, more precise details will become evident with
subsequent forecasts.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 628 PM CDT Tue Jun 30 2026

VFR conditions are expected to continue through the TAF period.
Wind gusts will start to wind down this evening as diurnal
heating comes to an end. Wind gusts will pick up again tomorrow
morning along the typical diurnal curve. Still some signal in
models for some LLWS tonight, but didn`t see a strong enough
signal for inclusion at this time.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 9 PM CDT Friday for MOZ001>008-
     011>017-020>025-028>033-037>040-043>046-053-054.
KS...Extreme Heat Warning until 9 PM CDT Friday for KSZ025-057-060-
     102>105.

&&

$$

DISCUSSION...SPG
AVIATION...Carletta