St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

702
FXUS63 KEAX 061902
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
202 PM CDT Sat Jun 6 2026

.KEY MESSAGES...

- Isolated to scattered storms are expected this afternoon and
  evening, with more likely shower and storm chances expected to
  increase from the south late tonight through Sunday night
  (70-90% chances at their peak Sunday afternoon and evening).

- Additional chances (20-50%) of showers/storms will continue into
  the early part of the work week next week.

- Warmer and more humid conditions will return for mid-week next
  week, with heat indices rising to the 90s to near 100 degrees
  across the area for at least a few days.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 159 PM CDT Sat Jun 6 2026

Some isolated to scattered thunderstorms are expected this
afternoon as a cut-off upper-level low continues to lift
northeastward from the TX Panhandle region, which can already
be seen on local radar at 2 PM/19z this afternoon. Ahead of the
upper low, an area of positive-vorticity advection and upper-
level diffluence will develop over the area along with warm air
advection will provide ample large scale forcing for convection
to develop once again for portions of the region. There remains
some uncertainty regarding the exact coverage of the convection
this afternoon, but the most likely locations to see storms will
be along and north of the Highway 36 corridor. Any storms that
fire off in this environment could become strong to severe,
given ample surface- based instability, with the 06.12z HREF and
REFS ensembles suggesting magnitudes around 2000 to 3000 J/kg.
However, a lack of robust deep- layer shear (values less than 20
knots) should help support more pulsey convection. Still, with
DCAPE values around 1000 J/kg per the latest RAP/SPC
mesoanalysis, and very high Pwats between 1.5 to 1.8", some
locally stronger wind gusts are possible, and SPC continues to
have our north-central and northeastern CWA in a Marginal Risk
(level 1 of 5) for severe storms today. Mid- level lapse rates
appear to be quite flat, so thinking that any hail that develops
would be small.

As we look to tonight through the day Sunday, the weather pattern
will remain active as the aforementioned upper-level low slowly
approaches our area, with persistent theta-e advection. We will have
continued off-and-on showers and storms throughout the day, with
gradually increasing Pwat values approaching the 2" mark! These
values would be anomalously high for this time of the year per the
NAEFS ensemble, with values near the 99% of climatology. With that
said, it appears that heavy rainfall and perhaps some flash flooding
will be of greater concern than severe weather, given a very weak
shear profile. WPC continues to have our entire area under a Slight
Risk (level 2 of 4) for excessive rainfall, and this prolonged
period of rainfall could exacerbate ongoing hydro issues. Much will
depend on the coverage and location of rainfall as the soils over
our northern areas remain more saturated than our southern areas.
With that said, we considered issuing another Flood Watch, but held
off for now due to the uncertainty of rainfall coverage. This will
be something to monitor closely.


&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 159 PM CDT Sat Jun 6 2026

The work week starts off with continued chances (20-50%) of showers
and storms Monday as a surface low takes shape over the eastern
Rockies via lee cyclogenesis and translates over the OK Panhandle
region by Monday morning per the latest GEFS and EC ensembles,
placing us once again in a warm air advection regime. Ample
instability and steep mid-level lapse rates around 7-8 C/km could
support some stronger convection Monday afternoon and evening, but
how things evolve will be conditional due to how prior convection
augments the meteorological environment.

Attention then turns to building heat and humidity for mid-week as
large upper-level ridging strengthens over the central CONUS.
Increasing Gulf moisture from anti-cyclonic flow around mid-level
ridging over the southeastern US will help boost the humidity
values, with dew points increasing to the middle to upper 70s across
the area. With high temperatures expected to warm to the lower 90s
over most locations, this will result in very muggy conditions and
dangerous heat index values rising to the upper 90s to lower 100s.
The latest LREF ensemble suggests 50 to 70% exceedance probabilities
of heat indices 95 degrees F or warmer, so confidence is decently
high for conditions to be quite sticky. Heat headlines may be
needed. While the forecast remains largely dry for Tuesday through
Thursday, there is an outside chance of showers and storms popping
up during this time frame at times due to a few passing shortwaves
Tuesday and Wednesday nights.

As we look towards the latter part of the week, relief from the heat
looks to come as a cold front is progged in many of the model
guidance to move through the area, with some chances of showers and
storms. However, there are significant timing differences with the
front, so it`s uncertain on the exact fropa timing, but consensus
blends do favor lower dew points compared to mid-week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1245 PM CDT Sat Jun 6 2026

A mix of VFR to MVFR conditions were seen over the area early
this afternoon, with a daytime cumulus field developing over
most of the area. The expectation is for locations that are MVFR
the ceilings should lift this afternoon, leading to improving
flight conditions. Attention then turns to periodic chances of
showers and thunderstorms this afternoon into Sunday. Coverage
of this activity appears to be more isolated to scattered in
nature this afternoon and evening before becoming more
widespread late tonight into Sunday. A low-level inversion and
humid air mass should support lowering ceilings late tonight
into Sunday morning, falling as low as IFR. MVFR visibility
reductions are also likely with any thunderstorm that form.
South to southeast winds will persist, remaining around 5 to 10
knots.

&&

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

&&

$$

SHORT TERM...Schultz
LONG TERM...Schultz
AVIATION...Schultz