St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

291
FXUS63 KEAX 122325
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
625 PM CDT Sun Apr 12 2026

...Updated 00z Aviation...

.KEY MESSAGES...

- Active weather pattern this week with multiple chances for
  strong to severe thunderstorms.

- Best chances for severe storms appears to be Tuesday evening
      into Tuesday night, Wednesday afternoon, and Friday
      afternoon into Friday night.

&&

.DISCUSSION...
Issued at 150 PM CDT Sun Apr 12 2026

A shortwave trough embedded within the larger scale
southwesterly mid/upper level flow is currently traversing
across eastern KS into Oklahoma, and has helped trigger
widespread rain showers across the CWA this morning and early
afternoon. These should continue to slowly push off to the east
northeast with the shortwave this afternoon. Rainfall totals
should generally remain under an inch for most locations,
although a few isolated areas could reach or even slightly
exceed 1". With widespread rain and cloud cover, have adjusted
today`s MaxT down a couple degrees across the board. Dry, mild,
and breezy conditions are likely for tonight into early Monday
morning.

By tomorrow afternoon, 35+ knot WSW H5 flow should overspread
our CWA downstream of the parent mid/upper trough across the SW
CONUS. With high temps reaching the lower to mid 80s and dew
points in the mid 60s, SB CAPE should exceed 2000 J/kg by mid
afternoon. However, despite the combination of instability and
decent deep layer wind shear, an EML providing strong capping
and a lack of forcing for ascent will very likely preclude any
chances for thunderstorms. A tightening pressure gradient
tomorrow afternoon should yield sustained SSW winds on the order
of 15 to 20 mph with gusts up to 30 to even 35 mph. A 50 knot
LLJ tomorrow night into early Tuesday morning should keep
surface winds elevated through the overnight period, with
overnight lows remaining in the mid to upper 60s.

On Tuesday afternoon, the SW CONUS trough will eject across the
Southern Rockies into the south central Plains, with
strengthening (45 to 55 knot) WSW mid/upper level flow
overspreading the region. Meanwhile, a surface low will deepen
near the west central KS/NE border, with a dryline extending to
the south southwest from the surface low. Strong surface heating
should allow for temperatures to rise into the mid to even
upper 80s on Tuesday afternoon, and with dew points in the mid
60s and steep lapse rates, ML CAPE should exceed 2500 J/kg.
Convective inhibition should be weaker on Tuesday
afternoon/evening thanks to strong surface heating and diurnal
mixing, but with weak synoptic scale forcing across the open
warm sector on Tuesday afternoon/evening, it still look like it
will be difficult to get convective initiation. However, if
storms do manage to initiate, supercells capable of all severe
hazards will be possible. The much more likely scenario, and the
scenario that is backed up by most recent CAMs, is convection
to initiate along the dryline across Kansas into Oklahoma by
late Tuesday, likely growing upscale into clusters or even a
line of storms as they approach the CWA late Tuesday night. The
severe risk should continue into Wednesday as the upper trough
and accompanying surface low and attendant cold front further
approaches and eventually moves through the region. However,
this risk will be largely dependent on how convection evolves
late Tuesday night into Wednesday morning and if the atmosphere
is able to sufficiently recover. SPC maintains a 15% (slight
risk) probability for severe weather across essentially the
entire CWA for Wednesday.

After a reprieve from the threat for strong to severe storms on
Thursday, yet another large scale upper trough is progged to
cross the Rockies into the Plains on Friday, with a moist and
unstable air mass in place across the CWA ahead of an
approaching cold front and beneath strengthening southwesterly
deep layer flow. This will present another threat for strong to
severe storms Friday afternoon into Friday night.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 623 PM CDT Sun Apr 12 2026

MVFR ceilings will continue for the next couple of hours across
the region, but should scatter out with any ceilings at VFR
through overnight. More MVFR ceilings though return Monday
morning and may linger into the afternoon. A strong cap is
expected to inhibit shower/storm activity on Monday across most
of the area. Winds will remain breezy generally out of the
southwest.

&&

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

&&

$$

DISCUSSION...Williams
AVIATION...Krull