St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

999
FXUS63 KEAX 131938
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
238 PM CDT Thu Aug 13 2026

.KEY MESSAGES...

- Dangerous heat continues through the end of the week and into
  the weekend for some areas. An Extreme Heat Warning is in
  effect along and south of the Missouri River. A Heat Advisory
  is in effect along and south of US-36.

- Chances for showers and storms continue in the vicinity of a
  stationary front fluctuating between southern Iowa and
  northern Missouri. Lingering cloud cover could mitigate high
  temperatures over the next few days.

- Cooler temperatures are forecast for early next week following
  a cold frontal passage on Sunday.

&&

.DISCUSSION...
Issued at 235 PM CDT Thu Aug 13 2026

Current analysis depicts a 500-hPa ridge covering much of the
central and eastern CONUS with troughing over both the far
eastern and western CONUS. At the surface, high pressure over
the Gulf and low pressure over Kansas continue to funnel Gulf
moisture into eastern KS and western MO resulting in the
persistence of hot and humid conditions. High temperatures today
and tomorrow are once again expected to be in the upper 90s,
with dew points in the mid-70s, leading to heat indices pushing
towards 110F. As such, the Extreme Heat Warning and Heat
Advisory remain in effect for eastern KS and northern/central MO
through 8 PM on Friday. Cloud cover and an outflow boundary
from convection in Iowa this morning has kept areas of far
northern MO slightly cooler and below Heat Advisory criteria.

A warm/stationary front extends northeast from the low pressure
center in central KS into central IA. This boundary is
expected to drift south into northern MO this evening and be
the focus for storm development across central KS into the
overnight hours as a weak shortwave moves through the flow and
interacts with the LLJ. Current thinking is that a cap across
northern MO will limit convective potential and the convection
will primarily remain to the west in central KS. However, recent
runs of the CAMs have shifted the axis of storm development
slightly further east. With PWATs sitting near 2", storms will
be very efficient precipitation producers, so training storms
along the frontal boundary would pose a flash flooding threat,
with 3- and 6-hr flash flood guidance being in the 2-2.5" and
3-4" range respectively. Aside from this, the severe threat with
any storms is fairly low, though some small hail and a wind
gust or two cannot be ruled out.

A secondary axis of convective development is forecast further
north early tomorrow morning, in central IA, closer to the
heart of the forcing from the shortwave. This convection should
largely stay north of the IA/MO border, but it is possible that
a cell or two could straddle the state line bringing heavy
rainfall chances to northern MO early tomorrow morning.

On Friday, the low pressure system is progged to lift into IA
and towards the Great Lakes region, with northern MO and eastern
KS remaining in the warm sector of the system. This will allow
the heat and humidity to continue into the weekend. The
stationary front is expected to remain positioned across far
northern MO through Saturday, with additional storm development
being possible along the front, which may lead to a continued flash
flooding threat into the weekend. However, confidence in timing
and location of any storms remains low at this time. Storms and
associated cloud cover may limit the heat potential on Saturday
across northern MO, but the full impacts remain unclear. As
such, the Extreme Heat Warning remains in effect across central
MO through 9 PM on Saturday and has not been expanded northward
as of now. A northward expansion may be needed in coming
forecast cycles depending on the evolution of the previously
discussed items.

The cold front of the low pressure system is expected to finally
push southward on Sunday, bringing some much needed relief from
the heat and potentially a few showers and storms. Unfortunately,
the relief will not last very long, as ridging is expected to
return by mid-week next week and a very similar pattern to the
current pattern emerges once again.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1216 PM CDT Thu Aug 13 2026

VFR conditions are expected through the TAF period at all four
terminals. Gusty southerly winds this afternoon should drop off
after sunset. Winds may vary in direction a bit at KSTJ through
the overnight, but should return to southerly by tomorrow
morning. There are some hints of LLWS being possible at the KC
Metro terminals overnight tonight, with the best chances at
KIXD, however, confidence is not high enough to include it in
the TAF as of now.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 8 PM CDT Friday for MOZ028>033-037-
     038.
     Extreme Heat Warning until 9 PM CDT Saturday for MOZ039-040-
     043>046-053-054.
     Heat Advisory until 8 PM CDT Friday for MOZ011>015-020>025.
KS...Extreme Heat Warning until 8 PM CDT Friday for KSZ025-103>105.
     Extreme Heat Warning until 9 PM CDT Saturday for KSZ057-060.
     Heat Advisory until 8 PM CDT Friday for KSZ102.

&&

$$

DISCUSSION...Carothers
AVIATION...Carothers