St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

645
FXUS63 KEAX 301724
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1224 PM CDT Thu Apr 30 2026

...18z Aviation Update...

.KEY MESSAGES...

- Scattered Showers Today; Isolated Non-Severe Storm Possible

- Cooler Through Saturday

- Warmer Temperatures Return Sunday

&&

.DISCUSSION...
Issued at 337 AM CDT Thu Apr 30 2026

Surface high pressure will shift eastward today while a weak mid-
level vort maxima moves on the backside of trough axis that is
lifting northeast of the area. Mid-level flow will be northerly
throughout the day and will push an H85 thermal boundary southward.
Throughout this afternoon this will be capable of generating
scattered shower activity. A few hundred J/kg of MUCAPE may be
present across the area that could result in a few deeper updrafts
capable of becoming a weak thunderstorm. Rainfall amounts still
range from just a few hundredths of an inch, with perhaps a chance
for a little over one-tenth of an inch in northern or northeastern
Missouri. Cloud cover will also steadily increase throughout the
afternoon as this disturbance moves through.

The mid to upper-level low and trough axis shifts toward the Great
Lakes region for Friday, but continues to leave the lower Missouri
River Valley in northerly flow. This may try to push another thermal
boundary southeastward between 850-700mb levels. A few CAMs attempt
to develop light showers along this forcing, but drier air is
expected to be in place after Thursday Night, which would more
likely result in evaporation before reaching the surface. Perhaps
could be able to spot some virga throughout the day on Friday. Have
placed scattered sprinkles in the forecast for Friday as this
forcing moves through, but very little is anticipated in the way of
QPF. Saturday and most of Sunday remain dry with the influence of
surface anticyclone passing through the region. Saturday will
continue to feature temperatures in the mid to upper 60s. A mid-
level short-wave starts to move into the Central CONUS early Sunday
and will work to develop a surface cyclone. This turns low-level
flow southerly and will promote WAA, boosting temperatures back into
the mid and perhaps upper 70s across a large portion of the forecast
area.

Mid-level pattern will be zonal to start of the work week but
several short-wave perturbations look to emanate from deeper trough
over the southwestern CONUS. This will keep low-level flow southerly
and promote high temperatures in the upper 70s to perhaps lower 80s
through the middle of the week. There will be lift available with
this pattern that will provide the opportunity for rain shower and
storm activity through the middle of the next week. By the end of
the week, temperatures will return closer to normal.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1222 PM CDT Thu Apr 30 2026

VFR conditions expected to prevail across the sites, with one
caveat. The trio of metro sites run the potential of seeing a
VCTS/VCSH to brief prevailing SHRA/TSRA this afternoon as a weak
frontal boundary drops through the area. Confidence is quite
low, but enough to have some mention of PROB30 there. Even among
the three KC Metro sites, confidence is least up toward KMCI.
Otherwise, current S/SSW winds will turn NW with the frontal
passage today then go light and variable tonight before
reestablishing NW late in the period.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...Curtis