St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

657
FXUS63 KEAX 072318
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
618 PM CDT Mon Sep 7 2026

...Updated 00z Aviation...

.KEY MESSAGES...

- Dangerous heat will continue Tuesday for most locations, and potentially
  into Wednesday for areas south of the Missouri River.

- Strong to severe storms are possible Tuesday afternoon into the
  overnight hours. And again on Wednesday afternoon.

- Cooler/ more seasonal temperatures move into the area for the
  later half of the week and through the weekend.

&&

.DISCUSSION...
Issued at 203 PM CDT Mon Sep 7 2026

Dangerous heat continues to afflict the area as upper-level ridging
remains across the middle of the country. That ridging spreads
eastward Tuesday with 594dam 500mb heights centered over Missouri
and southwest into Oklahoma. This will lead to dangerous heat
spreading back east to encompass most of the forecast area by Tuesday
afternoon. While the entire forecast area will see highs in the mid
to upper 90s Tuesday, our northeastern zones may lag on
moisture and thus heat index values don`t look as high as areas
further to the south and west. With that in mind, have issued a
heat advisory to the east of the ongoing heat warning. There is
potential that a portion of these headlines will need to be
extended into Wednesday afternoon. However that will be heavily
dependent on how convection from Tuesday evening through
Wednesday morning evolves and if any new convection develops
Wednesday afternoon. Right now, the most likely area that may
need to be extend would be along and south of the Missouri
River. After collaborating with our neighbors, decided to hold
off given the uncertainty with the convection and potential
effects on temperatures. If I had to put a probability to
whether the areas I mentioned are extended, I`d put it around
50-60%. So there is a fair amount of uncertainty as a result of
the front and potential for new convection along it.

Speaking of fronts, a fairly robust front will be moving into the
region late Tuesday afternoon and evening and slowly move south
through the overnight hours. Robust CAPE will build through the
day ahead of the front across northern MO/ northeastern KS.
Shear will be limited and decrease with southward extent as
stronger flow aloft remains well north of the area. But the
front will provide a focus for convective development, most
likely in the 00Z to 03Z time frame in our far northern/
northwestern zones. Initial development will pose a risk for
downburst winds and large hail. But this should trend to mainly
a wind hazard with time as front slides southward through the
overnight hours. Then for Wednesday afternoon, the forecast is
dependent on where that front or any outflow boundaries reside.
With the latest suite of guidance, the most probable area for
renewed convection looks to be in our southern zones. CAPE may
potentially be robust with ensemble mean SBCAPE values in excess
of 1500 J/kg. But this could be as high 2500 J/kg based on the
90th percentile of ensemble guidance. Shear may also be stronger
than Tuesday as the mid/upper level jet has shifted southward.

That cold front will finally bring an end to the extreme heat that
has plagued the area for nearly two weeks. High temperatures by
Thursday should be closer to seasonal normals, which now are in the
lower 80s to near 80 by the end of the week. Dewpoints are also
expected to fall into the middle 60s for most Thursday afternoon.
Temperatures rebound some for the weekend but we should still see
highs in the middle 80s through the end of the forecast.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 615 PM CDT Mon Sep 7 2026

VFR conditions expected for the TAF period as the front will
remain well off to the west over the Central and High Plains
this evening. Winds between 10-12 kts out of the south expected
Tuesday afternoon, with a few gusts above 15kts possible at
times.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 8 PM CDT Tuesday for MOZ028-029-037-
     043-053.
     Heat Advisory from noon to 8 PM CDT Tuesday for MOZ001>005-
     011>015-020>023-030>032-038>040-044>046-054.
KS...Extreme Heat Warning until 8 PM CDT Tuesday for KSZ025-057-060-
     103>105.
     Heat Advisory from noon to 8 PM CDT Tuesday for KSZ102.

&&

$$

DISCUSSION...CDB
AVIATION...Krull