St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

368
FXUS63 KEAX 222317
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
617 PM CDT Wed Apr 22 2026

.KEY MESSAGES...

* Strong to severe thunderstorms possible Thursday evening and into
  the early overnight.

  - Damaging winds remain the primary threat across the wider area.
  - A couple tornadoes possible with initial storms as well as embedded
    within lines of storms.
  - Large/severe hail most likely with initial storms

* Additional chances for showers and storms Saturday evening and
  again Sunday into Monday, including the potential for some to
  be strong to severe.

&&

.DISCUSSION...
Issued at 335 PM CDT Wed Apr 22 2026

Lots of moving parts as we gear up for another relatively active
stretch of weather. The large scale mid-upper level pattern remains
predominantly unchanged from previous forecasts, with long wave
trough (and developing cutoff low), ridging over the central CONUS,
and broad NW flow over the eastern CONUS. Currently at the surface,
sizable surface high over the SE CONUS and developing/deepening Lee
side surface low over eastern Montana have allowed prominent low-
level moisture to surge up through much of the Plains and Missouri
Valley. That moisture surge being the culprit for cloud cover and
suppressed temperatures seen much of today.

As we work into Thursday, mid-upper pattern remains expected to
evolve into a messy Omega Block pattern look as the western trough
drifts eastward through the Intermountain West develops a cutoff low
and a subsequent cutoff low develops in/around Nova Scotia. This
will amplify existing ridging over the central CONUS, also allowing
deeper moisture return and increased S/SW flow through the profile.
Additionally, a shortwave/lobe of energy will be rounding the base
of the larger western trough, inducing additional Lee Cyclogenesis
over the southern Rockies. All of this will help tee up our next
strong/severe storm opportunity Thursday evening/night. Synoptic and
available hi-res guidance continue to point toward a fairly narrow
area ahead of the surface boundary/dry line that will be favorable
for strong to severe storms, including a relatively narrow area
SB/ML CAPE values >2000-2500 J/kg, deep/0-6km shear 40-50kts, and
good low level hodograph curvature among other things. Over the
larger warm sector (much of the forecast area), ongoing moisture
advection likely yields cloud cover much of the day but too may
still output SB/MLCAPE values approaching 2000 J/kg, more limited
cap in areas, and at least semi-supportive wind profiles/hodographs
for organization.

Some guidance has pointed toward possibility of a few
isolated/discrete storms on the leading edge of the deeper
moisture/WAA plume, though most keep bulk of convective initiation
back west along the surface boundary/dry line. Should a few discrete
storms go in the wider warm sector, most likely over northern
Missouri, all modes would be possible, but remains a low probability
scenario at this point in time. Of much greater certainty is
convection along/preceding the surface boundary/dry line over SE
Nebraska and central/eastern Kansas during the evening. With the
above mentioned environment, all hazards too will be possible. Large
hail and tornadoes would be most likely with any discrete initial
convection, but likely is a short lived opportunity with rapid
upscale/linear growth expected given near parallel mean-winds/deep
shear profiles to the boundary. The more widespread threat likely
becomes wind (bolstered by hi-res depictions including HRRR NN) as
linear segments develop and propagate eastward. A QLCS tornadic
threat may continue as well with noted 0-3km shear vectors that
would orient well for northern portions of bowing segments.
Conceptual model, bolstered by hi-res guidance, suggest general
weakening as this activity translates eastward into/through
Missouri. Timing wise, initial convection may go up over SE
Nebraska/NE Kansas as early as around 21z and growing upscale from
there. The NE to SW orientation places activity into NW Missouri not
long after 21z, while KC Metro may be 02z Fri (9pm local) or later.
SPC does have Sig 1 hatching for both tornadoes and hail, tied most
closely initial and/or discrete convection. Eastward extent of this
hatching may be a bit too far east, with current best threats for
those looking to stay to the west of the KC Metro among other
locations. Otherwise, the broader SPC Day 2 Slight and associated
probabilities appear well placed.

Active pattern remains in place into and through the weekend as a
compact shortwave is expected to move though the southern stream. As
this shortwave trough approaches, storm chances may return as soon
as Saturday, but appears more likely just S of the area. More
substantial threat returns Sunday and Sunday night/overnight as the
main shortwave and associated surface low moves into the Plains.
Prevailing track around KS/OK border area, lifting additional
moisture and warm sector through the area Sunday and likely yields
some elevated non-severe showers/storms as the warm front lifts
northward. Surface low approaches Sunday evening and overnight,
including continued depictions of area of >1500-2000 J/kg MUCAPE and
jet streak nosing in yielding >40-50kts. Timing is not traditional,
but broad lift with shortwave trough and jet position are of note.
Any convection in this environment may post a hail/wind threat
primarily, especially if it can sustain into Monday daytime as the
system continues to push E/NE. Of note too at this point, we may be
in line for hydro issues with Thursday evening rains, Sunday rains
with lifting warm front, and then additional as the mid-upper
shortwave and surface low move across. In total, some depictions of
>4-5 inches through this time frame. Keep an eye on Sunday/Sunday
night as details continue to evolve and come into better focus.

Phew, by Monday large scale pattern becomes more zonal in nature
with some variance in additional shower/storm/precipitation
opportunities among deterministic guidance but honing in on next
Wednesday. Temperatures largely on the seasonal to seasonally warm
side of things throughout the forecast period as well.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 614 PM CDT Wed Apr 22 2026

MVFR ceilings are expected to be fairly persistent through the
forecast period. Could also see some areas of drizzle develop
after 06Z Thursday, most concentrated across NW Missouri. Gusty
south winds continue, with potential for thunderstorms building
in from the west after 00Z Friday.

&&

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

&&

$$

DISCUSSION...Curtis
AVIATION...BT