St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

354
FXUS63 KEAX 031729
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1229 PM CDT Wed Jun 3 2026

...18z Aviation Update...

.KEY MESSAGES...

* Quiet, dry, and generally comfortable again today

* Shower and storm chances return later Thursday, continuing through
  the weekend and into at least early next week.

* Warmer and humid conditions return by the end of the week,
  continuing through the 7-day forecast.

  - Heat index values into the 90s, including mid-upper 90s,
    possible at times.

&&

.DISCUSSION...
Issued at 332 AM CDT Wed Jun 3 2026

Conditions across the area overnight have remained on the quiet and
comfortable side with clear to scattered cloud cover and light
easterly winds continuing to keep dew points suppressed. Remainder
of the overnight and morning hours will see this continue, with some
increasing lower level cloud cover and winds shifting clockwise out
of the SW and S. The cloud cover and dew point disparity across the
region will yield lows ranging from the mid 50s (east) to low to mid
60s (west).

Today tends to be a rinse and repeat of yesterday for much of the
area with temperatures in the low to mid 80s and pleasant dew
point/humidity conditions. The main difference from yesterday will
tend to be winds shifting out of the SE/S through the day, but
continuing to advect in the lower humidity air mass.

Changes become more noticeable by Thursday, setting the table for the
prolonged return of warmer and humid conditions and chances for
showers/storms. The large surface high and mid-upper level ridging
responsible for the current quiet and pleasant conditions will have
shifted E/SE and flattened respectively. This will allow plume of
deep moisture return to also shift eastward into/across the forecast
area. Initially Thursday that will yield warmer and more humid
conditions, but mostly dry through the day. Synoptic deterministic
guidance has come into better agreement on a northern stream
shortwave crossing the Plains Thursday and bringing about the first
(of many) chances for showers/storms to the area as early as
Thursday afternoon. Soundings point towards an uncapped or nearly
uncapped environment that may yield scattered non-severe
thunderstorms through the afternoon and evening with the approaching
shortwave and ongoing WAA. Otherwise the best opportunity will
primarily reside over W/NW portions of the forecast area closer to
the core shortwave, but appears poised to struggle to produce more
than non-severe thunderstorms with better deep shear (organization)
support displaced NW into Nebraska and Iowa. Friday sees another day
re-priming the area and shifting general conditions eastward
slightly. It is possible some ongoing activity into Friday morning,
but again non-severe in nature. By the evening, another shortwave
within the northern stream approaches the area and may yield the
first opportunity for a few strong/severe storms. Parameter space
over N/NW areas is forecast to be notably better than Thursday with
lapse rates, strong instability (>2500-3000 J/kg MUCAPE), and more
supportive deep layer shear within various deterministic guidance.
This potential too is reflected within the current SPC Day 3
Outlook, where much of NE Kansas and NW/N Missouri his highlighted
with a Marginal Risk and a Slight Risk displaced just to the NW in
Nebraska and Iowa.

Into the weekend, a longwave trough/cutoff low digs into the PNW,
causing mid-upper level ridging to amplify across the
central/northern Plains. Concurrently, a broad trough/weak cutoff
low is expected to lift northward out of Texas, which will continue
shower/storm chances through the weekend. While instability
depictions >1500-2000 J/kg MUCAPE remain, the chances for
strong/severe are tempered by less supportive deep shear profiles
given the broad troughing/low. A probable scenario would be for
scattered to widespread showers/non-severe thunderstorm activity as
this broad synoptic scale lift overspreads the area. During this
time 850mb temps warm into the mid-upper teens deg C, which would
begin to put upper 80s and low 90s in play for highs. Some
uncertainty though given dependency on cloud cover and precipitation
coverage and timing. Should upper 80s/touching 90 be achieved,
existing (at that point) humid conditions would push heat index
values into at least the mid 90s. For now, the NBM values in the mid-
upper 80s with head index values into the low 90s are reasonable,
and hotter conditions more conditional.

Blocking mid-upper level high over the Great Lakes prevents
substantial pattern change over the area, continuing
shower/thunderstorm opportunities and warm/humid conditions into at
least early next week. For now, this yields a similar forecast as
the weekend... primarily showers/non-severe thunderstorms, highs
into the mid-upper 80s and heat indices into the lower 90s.

&&


.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1227 PM CDT Wed Jun 3 2026

VFR conditions are ongoing across the region, and are expected to
continue throughout the TAF period. Mid-level clouds this afternoon
will gradually clear after peak heating, with mostly clear sky cover
for the overnight. Clouds will begin to increase again tomorrow
morning, with sfc winds shifting to a southerly component.

&&

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

&&

$$

DISCUSSION...Curtis
AVIATION...Padgett