St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

766
FXUS63 KEAX 201125
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
625 AM CDT Mon Apr 20 2026

.KEY MESSAGES...

- Above normal temperatures and breezy south southwesterly winds
  are expected today through Thursday.

- Shower and thunderstorm chances return Thursday afternoon into
  Friday as a cold front is projected to move through the
  region.

     - Strong to severe thunderstorms and locally moderate
       rainfall may be possible.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 246 AM CDT Mon Apr 20 2026

Current H5 analysis shows high amplitude troughing across the
eastern CONUS, troughing off the West Coast over the Pacific
Ocean, and relatively high amplitude ridging across the western
CONUS between the two troughs. Over our CWA, 50 knot
northwesterly flow continues at the H5 level on the western edge
of the eastern trough. At the surface, a cold front made its way
southward through the region late yesterday evening into early
this morning, with a 1028 mb surface high analyzed across the
Upper Mississippi Valley. This has shifted surface winds to
easterly, with clear skies and temperatures in the mid 40s to
lower 50s for most locations, except for far NE Missouri where
temperatures have dropped into the the 30s (Frost Advisory
remains in effect through 9 AM for Putnam and Schuyler
counties).

By later today, the aforementioned cold front that progressed
through the CWA last night will lift back northward through the
CWA as the surface highs slides eastward toward Lake Erie and
low level flow turns south southwesterly and strengthens in
response to 850 mb troughing extending from Manitoba/Ontario
into the Southern Plains. Meanwhile, at the H5 level, height
rises will build in from the west as the eastern edge of the
mid/upper ridge impinges on the region. This should send
afternoon high temps into the mid 70s, usher in some moisture
return with dew points rising from the mid 30s this morning to
the mid 40s by late this afternoon, and increase south
southwesterly surface winds to around 15 mph with gusts up to 25
mph.

On Tuesday, a subtle shortwave embedded within the northwesterly
flow aloft is progged to translate out of the Northern Plains
and into the Midwest. This may generate some precipitation from
far NE Missouri into SW Michigan Tuesday evening, but PoPs
remain below 15 percent for our CWAs portion of NE Missouri.
Otherwise, even warmer temperatures are likely on Tuesday, with
afternoon highs reaching the upper 70s to even lower 80s
(primarily NE KS and NW MO) and continued moisture return, with
dew points rising into the mid 50s. Furthermore, enhanced
southwesterly surface winds will continue, with sustained winds
on the order of 15 to even 20 mph and gusts up to 30 mph.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Issued at 246 AM CDT Mon Apr 20 2026

The western mid/upper trough is projected to enter into the
western CONUS by Wednesday morning, reaching the Intermountain
West by Wednesday afternoon with ridging continuing over our CWA
downstream. Above normal temperatures and breezy southerly winds
should continue, with highs in the mid to upper 70s.

The H5 low is progged to enter into the Northern Plains by
early Thursday afternoon, with associated troughing extending
southward into the Southern Plains and increased southwesterly
deep layer flow overspreading the CWA. Meanwhile, a strong
surface cyclone should enter the Dakotas by early Thursday
afternoon, moving northeastward into southern Manitoba
throughout Thursday afternoon and evening, with the attendant
southward extending cold front approaching the CWA from the
west.

Continued theta e advection should help dew points reach
the low to mid 60s by Thursday afternoon/evening, and with a
plume of 1000 to 1500+ J/kg of CAPE ahead of the approaching
front and around 30 to 35 knots of deep layer bulk shear,
organized updrafts capable of producing strong to severe storms
will be possible Thursday afternoon/evening/night. Storm mode
may be initially discrete or semi discrete, but with mid level
flow mostly parallel to the front, storms will likely grow
upscale into one or more linear segments. While SPC maintains
the 15% severe risk across the CWA for Thursday afternoon into
Thursday night, some factors working against the potential for
widespread severe weather across our CWA include only modest
deep layer shear and somewhat skinny CAPE profiles, as well as
a fairly high potential for a linear storm mode by the time
storms enter into our area.

In addition to the severe potential, models suggest a plume of
1.25 to 1.5" PWATs ahead of the front, which may promote locally
moderate rainfall. WPC continues to highlight the entire CWA
within a marginal risk for excessive rainfall. The most recent
NBM run gives around a 20% chance for rainfall to exceed 1"
across NE KS into NW Missouri, with around a 50% chance across
the KC metro, peaking at around 60% along a narrow corridor from
Butler to Sedalia. The cold front should move through the
region from northwest to southeast overnight Thursday night into
Friday morning. PoPs linger through Friday afternoon before
clearing the region to the east by Friday evening/night.

As we head into the weekend, models suggest the potential for a
deepening closed mid/upper low developing over the Northern
Plains and Upper Midwest near the Canadian border, potentially
phasing with another trough moving into the western CONUS and
entering into the Plains. This would keep rain chances in the
forecast, with the current forecast showing generally 30 to 40
percent PoPs from Saturday afternoon into Sunday night. Near
normal temperatures (highs in the mid to upper 60s) are favored
for Friday through Sunday.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 619 AM CDT Mon Apr 20 2026

VFR conditions are expected through the period, with clear
skies through the vast majority of the period (scattered high
level clouds move in after 6z Tuesday morning). Southeasterly
winds this morning around 10 knots should become south
southwesterly by early afternoon, increasing a bit with
sustained winds around 12 knots and gusts up to 20 knots. Gusts
up to 20 knots may continue through the overnight period.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Frost Advisory until 9 AM CDT this morning for MOZ007-008.
KS...None.

&&

$$

SHORT TERM...BMW
LONG TERM...BMW
AVIATION...BMW