St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

770
FXUS63 KEAX 232349
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
649 PM CDT Thu Apr 23 2026

.KEY MESSAGES...

* Strong to severe thunderstorms will move into and across the area
  this evening into the early overnight.

  - Initial storms to the west are expected to carry the
    strongest/greatest potential, with gradual weakening as they
    translate east into and across Missouri

  - Any discrete (single) storms will carry an all hazards
    (hail, wind, tornado) risk.

  - Storms expected to congeal into a line through the evening,
    and would transition primary hazards to damaging winds a few
    short lived tornadoes possible along the line

* Active weather pattern looks to continue through the weekend and
  into Monday. This includes multiple chances for strong to severe
  storms.

  - Saturday evening: mainly S and W of the KC Metro

  - Sunday night/overnight: mainly S and W of line from Maryville
    to Jefferson city

  - Monday: Over much of the area, especially east

* Total rainfall accumulations from today through Monday could
  approach 3 to 4 inches across the region. This could yield
  some river and areal flooding concerns.

&&

.DISCUSSION...
Issued at 256 PM CDT Thu Apr 23 2026

A lot to unpack with this discussion.

Currently, storms are ongoing or continue to initiate over portions
of IA/NE/KS along an occluded (IA/NE) to dry line (KS/OK) boundary
extending southward out of a surface low in southern Manitoba. With
at least some sunshine along and ahead of this boundary and
concurrent with ongoing low level moisture advection, an unstable
and severe prone environment has prevailed. SPC Mesoanalysis points
to a corridor of MLCAPE >2500 J/kg concurrent with little to no cap,
>35-40 kts effective shear, steep mid-level lapse rates, and
increasing DCAPE values as you work southward from the KS/NE border.
All of this yields an unsurprisingly robust environment for at least
large hail and damaging winds. Modeled hi-res hodographs near the
boundary exhibit limited low level curvature, but forecasts suggests
some improvement as activity translates eastward. In the immediate
term, this suggests very large hail and damaging winds, with a
secondary tornadic threat. All good and well, but we are a few hours
out from activity for much of the forecast... which general
expectations are for more linear segments or clusters to form if not
full blown QLCS. Cloud cover over much of the area today has limited
the degree to which we have been able to destabilize, reflected in
the Mesoanalysis depicting showing ~1000-1500 J/kg MLCAPE values and
significant existing capping. So the show will be the linear
segments/QLCS when it arrives vs any notable open warm sector
potential. At that point, expectation remains for primary threat to
be for damaging straight line winds and the potential for some QLCS
tornadoes along segments that are able to best orient themselves
orthogonal to increasing magnitude 0-3km shear vectors. Given more
limited instability over the area, this keeps too the expectation
for greatest magnitude severe over western areas of the CWA and
gradual weakening as it moves eastward. WOFS runs and additional hi-
res guidance continue to regularly depict bowing convective
segments, which bolsters both the straight line wind and QLCS tor
thinking and all but eliminates near-severe to severe hail. SPC Day
1 updates, including introduction of 30 percent wind and additional
Sig 1 hatching generally in line with local thinking, albeit the Sig
1 tor may be a bit far eastward for our liking. That said, there is
always a butt/caveat... and here that is if there can be any
discrete or semi-discrete convection that is able to develop or
maintain into the evening and toward the metro, forecast low level
wind profiles/hodographs suggest an increased tornado threat. So,
keep an eye on storm mode. Linear/QLCS is primarily expected as
everything translates into the area, but a discrete/semi-discrete
storm will carry an elevated tornado threat. Overall, activity moves
out of the KC Metro area by around/after 10/11pm. By that time,
majority of the severe threat for damaging winds and QLCS tornadic
activity likely to be winding down as the general environment
becomes more prohibitive. General/non-severe thunder would continue
into the overnight and across the remainder of the area with true
cold front likely trailing behind by a couple/few hours.

Quiet day Friday, but the active weather pattern continues
into/through the weekend as the broader pattern continues to suggest
a messy Omega Block look setting up over the Northern CONUS into
Canada.

Saturday presents the next potential for storms, even severe, as a
shortwave traverses southern stream and surface low development over
Southern High Plains. Deterministic synoptic guidance broadly
depicts afternoon/evening development in the vicinity of a warm
frontal boundary laid up somewhere in Kansas. Currently S/SW
portions of the area (think KC area and S/SW) may be clipped by this
activity. General expectation would be for initial eastward
progressing then likely diving SE along the depicted CAPE gradients
into the evening. All hazards likely with initial convection, then
toward wind with likely MCS development given the wind and thermal
environments.

More substantial shortwave trough well depicted by synoptic
deterministic guidance moving through the southern stream, and will
provide yet another opportunity for strong/severe storms. A lot has
to transpire before we get to this point, but guidance has many
pieces in place for a potential higher end severe weather day. This
includes significant low level moisture return, potentially
significant MUCAPE depictions, pretty ideal jet placement, nicely
curved hodographs, etc as the shortwave trough and surface low
lift NE. For a few cycles, timing has been questionable, but a
recent slowing has pointed toward the warm sector remaining in
place over at least eastern Missouri into Monday afternoon. That
would allow much of the above to be in place. Any further
slowing and the entirety of Missouri could be of concern Monday
itself. But of note too, the unquestionable lift with this
system may allow for at least strong storms Sunday overnight
that could grow upscale in magnitude Monday morning/afternoon if
they are ongoing. Certainly a time period (Sunday overnight
through Monday) to watch closely as the forecast continues to
zero in on track and timing of this shortwave trough and
attendant surface low.

By Monday, should we realize multiple rounds of showers and storms,
we may be dealing with at least minor or nuisance water issues
within the area. Whether that be river flooding or localized
areal/flash flooding considering it is possible some areas see as
much as 4 inches through this time period.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 649 PM CDT Thu Apr 23 2026

A line of thunderstorms will move in from the west/northwest,
impacting all four terminals by 01Z tonight, dropping VIS/CIGs to
MVFR thresholds. The main line of storms should clear all terminals
by 04Z with lingering rain continuing until 05/06Z. Have opted to
include a PROB30 for -TSRA for low-end potential behind the primary
line. Precipitation should end by 06Z with clouds clearing out by
12Z Friday.

&&

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

&&

$$

DISCUSSION...Curtis
AVIATION...Macko