St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

967
FXUS63 KEAX 211113
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
613 AM CDT Sun Jun 21 2026

.KEY MESSAGES...

- Heavy rainfall resulting in flash flooding is possible early
  this morning and Sunday afternoon. A Flood Watch is in effect.

- Severe storms (mainly strong winds) possible early this
  morning.

- Additional severe thunderstorm redevelopment is possible
  Sunday afternoon from Kansas City south and southeast.

&&

.DISCUSSION...
Issued at 230 AM CDT Sun Jun 21 2026

Widespread showers and storms have moved from southeastern NE
and eastern KS into northwestern MO this evening. How this
convection evolves through the morning is the primary concern of
this forecast cycle. A well-estabilished MCS in south central KS
has pivoted from a southeast motion to an eastward propagation
with the development of an MCV on the northern edge. As the LLJ
has ramped up over the last couple of hours, a distinct bowing
segment has formed. The current forecast track would have the
center of this bow moving either just south of the CWA or
through southern Linn (KS) and Bates Counties meaning that
severe weather, particularly severe winds, is possible across
eastern KS and far west-central MO, including the KC Metro.
However, given the timing of this system (well after midnight),
the expectation is for a weakening trend as it advances
eastward, so some uncertainty remains in the true severe weather
potential across the southern portion of the CWA. However,
given that there is the potential, a Severe Thunderstorm Watch
has been issued for the KC Metro and areas south through 6 AM
CDT.

A more concerning trend that has developed over the past few
hours is the potential for training storms along the I-70
corridor leading to flash flooding. Storms across northern KS
and northern MO have been slowly shifting south and have begun
to orient themselves in a west-to-east manner along the I-70
corridor in central KS resulting in prolonged periods of heavy
precipitation (rainfall rates of 1-2 inches per hour). This
looks poised to continue into eastern KS and western MO, which
could result in 2-4 inches of rain in just a couple of hours
across northern MO. Current 3-hr flash flood guidance is ~1.5-2
inches, so this is quite concerning. A Flood Watch remains in
effect through 7 PM CDT for all of western MO and eastern KS.

This complex of showers and storms is expected to continue
through the morning and exit the area to the east by early
afternoon. A remnant outflow boundary/modified warm front will
be draped across central MO. This boundary will be focus for
renewed convection this afternoon (development around 1-2 PM
CDT) before a cold front sweeps through the area with the best
chances coming along and south of I-70. Elevated PWATs (in
excess of 2") will allow for effective rainfall rates and
another chance for flash flooding. Afternoon MLCAPE values of
1000-2000 J/kg paired with deep layer shear on the order of
40-45 kts will also allow for a severe weather threat. The
primary threats are wind and hail, but given the presence of a
boundary in the area, certainly cannot rule out a tornado or
two. North of the boundary, there is a threat for elevated
storms, which creates the potential for hail and perhaps a
marginally severe wind gust. This thinking aligns with the SPC
as the southern portion of the area is in a Slight (Level 2 of
5) Risk and areas north of I-70 are outlined in a Marginal
(Level 1 of 5) Risk.

Moving past Sunday, a lull in active weather looks to be on the
way. High pressure builds into the area on Monday with upper-
level zonal flow. Temperatures will be cooler after the cold
frontal passage Sunday afternoon/evening with highs in the mid-
to-upper 70s. A gradual warming trend is expected through the
first half of the week with temperatures climbing into the low-
to-mid 80s. Precipitation chances remain minimal through the
majority of the week before the next chance (20-40%) moves in on
Friday with a mid-level shortwave, however, a good amount of
uncertainty remain that far out.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 610 AM CDT Sun Jun 21 2026

The heaviest rainfall should be east of the terminals by 12Z and
with thunder on a downward trend over the past couple of hours,
have opted for no mention of TS in the TAFs. MVFR CIGs look to
hang around into the afternoon before clouds scatter out for a
bit. MVFR CIGs are expected to return overnight tonight and
should persist through 12Z on Monday. Winds are expected to be
gusty this morning. All four terminals may be a bit squirrelly
in direction out of the gate due to the ongoing showers/storms,
but expect a primarily southerly/southwesterly direction through
the morning before flipping to northerly this afternoon. There
is a low-end chance for convective redevelopment near the KC
Metro TAF sites this afternoon, particularly south of I-70,
hence the PROB30 at KIXD. Did not include a mention of it at
KMCI and KMKC, but cannot fully rule it out.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Flood Watch through this evening for MOZ001>008-011>017-
     020>025-028>033-037>040-043>046-053-054.
KS...Flood Watch through this evening for KSZ025-057-060-102>105.

&&

$$

DISCUSSION...Carothers
AVIATION...Carothers