St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

380
FXUS63 KEAX 130350
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1050 PM CDT Tue May 12 2026

.KEY MESSAGES...

- Isolated Showers/Storms Tonight; Strong to Severe Storm Possible

- Cooler Wednesday, but Warming Back Up Through End of Week

- Strong to Severe Storms Possible Thursday, Saturday, and
  Sunday

&&

.DISCUSSION...
Issued at 343 PM CDT Tue May 12 2026

Short-wave trough and surface cyclone are located over the Upper
Midwest as of 20z this afternoon, with trailing cold front
positioned from Concordia KS to just southeast of Des Moines IA.
Visible satellite imagery is showing cumulus development along the
leading edge of this cold front. This will become the focus for
convergence through the evening hours, and may be capable of
generating scattered shower and thunderstorm activity. Moisture has
gradually increased throughout the afternoon, but dewpoints are
still only in the lower 50s across most of the region. Moisture will
be a limiting factor in deep convective initiation through this
evening. A narrow corridor of CAPE between 500-700 J/kg may develop
along the leading edge of the cold front, with deep layer shear
around 40kts. If the moisture can be realized, a few strong to low
end severe storms may be possible, especially along a line from the
KC metro the Saline County Missouri, and areas southeastward of
this. Steep boundary lapse rates may allow for a few stronger wind
gusts, along with shear strong enough to support hail up to around
the size of quarters with strongest storms. However, CAM cycles
through the afternoon remain unexcited about strong storm
development, as dry air entrainment will remain a large factor. The
primary short-wave with this system looks to remain north of the
area as well, leaving the cold front as the only notable forcing to
try and get activity going. The cold front should push through the
area a few hours after midnight tonight.

Wednesday will be cooler with the passage of the cold front, and
stronger dAVA allowing a surface anticyclone move into the region.
H5 ridge axis passes through the area later in the afternoon as
another short-wave trough moves through the area. By Thursday, this
shifts low-level flow southwesterly across the area, which will help
boost temperatures back into the mid and upper 80s across much of
the area. Moisture return remains in question for Thursday afternoon
and evening, depending on how deep any surface cyclone over the
Front Range becomes. Current trends suggest Thursday may only see
dewpoint temperatures in the upper 40s to lower 50s, which may limit
shower/storm development through much of the afternoon. Although the
boundary layer may be able to destabilize, it may also remain very
well capped for most of Thursday. Friday will see WAA increase,
pushing temperatures into the upper 80s, and depending on moisture
transport and cloud cover, there is potential to hit the lower 90s
on Friday. Additional shower and storm development is possible as
moisture transport should begin to increase, especially for areas
along and south of Interstate 70. The main question will be if there
will be enough forcing to overcome any capping.

Persistent short-wave perturbations through the weekend will help to
maintain southerly flow in the lower troposphere, and greater
moisture transport across the Plains and lower Missouri River Valley
should lead to a more favorable thermodynamic environment for storm
initiation, especially Saturday and Sunday. The 15% slight risk
clips far western portions of the forecast area on Saturday, and
then covers more of the area on Sunday. Specific mesoscale details
are still difficult to point out. But the large scale pattern and
moisture transport point to favorable conditions for shower and
storm development, and if the kinematics align favorable, could
produce severe storms or even foster MCS development in the evening
hours. Temperatures through the weekend will remain in the upper
80s, and depending on cloud cover, may continue to see chances to
climb into the lower 90s.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1050 PM CDT Tue May 12 2026

VFR conditions continue for the duration of the forecast
period. Winds shift to the NW behind a cold front that
progressed through the area. High pressure continues to build
into the region keeping sky coverage SKC. Diurnal mixing kicks
up wind gusts mid to late morning continuing through the
afternoon. Gusts dissipate after sunset.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...Pesel