St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

663
FXUS63 KEAX 011821
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
121 PM CDT Mon Jun 1 2026

.KEY MESSAGES...

* Strong to severe thunderstorms may develop along and south of I-70
  later Sunday evening. The strongest storms would be capable of
  producing damaging winds, large hail (2"+ possible, mainly south
  of the Kansas City metro), and potentially an isolated tornado.
  Heavy rainfall could lead to localized flooding.

* Lingering showers and storms early Monday. Low-end severe threat
  Monday morning for damaging winds and hail as MCS continues to
  progress through Missouri. Heavy rainfall could also be a hazard.

* Hot and humid Monday with heat indices in the 90s. Apparent
  temperatures to be reflective of actual air temperatures in
  the 80s starting Tuesday, providing a few days of relief.

&&

.DISCUSSION...
Issued at 853 PM CDT Sun May 31 2026

Evening/overnight storm potential tonight into early Monday morning
remains the most pressing aspect of the forecast period. Over the
course of the day, instability has grown appreciably, with recent
SPC mesoanalysis indicating a 3500-6000 J/kg SBCAPE gradient from
the northern portions of the Kansas City metro into the far southern
portions of the CWA. ACARS soundings out of KMCI continue to depict
a stout capping inversion with multiple failed attempts at
convection in eastern Kansas observed via satellite. A diffuse
outflow boundary extending from central Kansas into south-central
Missouri has been the primary area of focus for these initiation
attempts, but as of about 800 PM CDT, only one remotely successful
updraft has been able to form in Douglas County, KS. Isolated
development will continue to be possible over the next 1-2 hours,
but more widespread convection will likely have to wait for improved
mid/upper-level support, namely in the form of CVA as a shortwave
moves through the flow aloft. Initially, storms are expected to be
discrete and capable of all severe hazards. High resolution guidance
points to over 4000 J/kg MUCAPE and around 1000 J/kg of CAPE in the
HGZ, with values nearing 1500 J/kg south of I-70. In this
environment, discrete storms could produce very large hail. Despite
poor low-level flow overall, the potential for cell and boundary
interactions in such a highly unstable environment supports an
isolated tornado threat. PWATs > 1.5" across the area provides a
heightened flood/flash flood threat overnight, mainly along and
south of I-70 where the greatest moisture convergence is colocated
with the strongest updraft potential. Soils across southern and
central Missouri have reduced infiltration capacity due to earlier
rainfall, further heightening flood concerns in these locales. As a
weak low-level jet protrudes into the area tonight, storms will be
encouraged to grow upscale as they move into central Missouri. With
quite a bit of instability persisting into the overnight hours, the
severe threat will continue through much of the early morning as
storms progress east. Flood/flash food concerns will also remain
with potential training as the event progresses.

Around sunrise, the main storm system is expected to have exited the
eastern fringes of the CWA, though some lingering precipitation is
possible. Light winds, clearing sky conditions, and small dewpoint
depressions could allow patchy fog to develop in the early morning
hours, especially further north and west behind the MCS. Surface
dewpoints look to return to the low/mid 70s, leading to a muggy
first day of June. Northerly and easterly surface flow that sets in
behind the surface low with ridging building overhead. This will
provide some reprieve as the area loses its connection to Gulf
moisture, keeping uncomfortable heat indices at bay until late in
the week when surface flow becomes increasingly southerly once again
as an upper/mid level trough approaches the region on Thursday. This
system will bring another active period of weather to the area
Friday through the weekend.

&&


.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 116 PM CDT Mon Jun 1 2026

An area of low BKN clouds overshadows the terminals keeping
conditions just under VFR. Sky coverage is expected to become
more SCT to FEW as the afternoon goes on although CIGs may
remain between 2kft-5kft. Otherwise winds remain generally
northeasterly looking to become more easterly overnight.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.

&&

$$

DISCUSSION...Macko
AVIATION...Pesel