St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

449
FXUS63 KEAX 151134
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
634 AM CDT Fri May 15 2026

.KEY MESSAGES...

- Active weather pattern continues into early next week.

- Strong to severe storms will be possible tonight, primarily
  across NW Kansas into NW Missouri.

- Marginal risk for strong to severe storms on Saturday and
  Sunday, once again primarily for NW Missouri.

- Best chance for severe weather comes Monday afternoon into
  late Monday night. All severe hazards will be possible.

  - Locally moderate to heavy rainfall will also be possible.

- Chances for strong to severe storms may linger into Tuesday.

- Hot temperatures expected today through Monday.

&&

.DISCUSSION...
Issued at 208 AM CDT Fri May 15 2026

Current H5 analysis shows a closed mid/upper low centered over
the northeast US with another (and much deeper - 532 dam) closed
low centered over central Manitoba with a band of 50+ knot
westerly H5 winds extending from the Pacific NW into the Upper
Mississippi Valley. Further south across our CWA, relatively
weak (less than 30 knot) zonal westerly flow continues at the H5
level. However, a 45+ knot southwesterly low level jet has
developed early this morning, which has helped to generate a few
relatively high based showers and thunderstorms across the
region, with these likely to exit to the east by later this
morning.

Later this morning, a warm front should lift southwest to
northeast through the CWA, with south southwesterly surface flow
increasing out ahead of a pair of surface lows across eastern
Nebraska and the OK Panhandle. Meanwhile, a weak shortwave
trough is progged to move out of New Mexico into Texas. This
will yield strong temperature and moisture advection into the
CWA, with temperatures likely rising into the upper 80s to lower
90s and dew points increasing from their present values in the
mid 40s to mid 50s to the lower 60s by this afternoon/evening.
Today`s record high of 91 degrees (set in 1941) will be
threatened today at MCI, with the current forecast showing 91
degrees. Warm temperatures and 60+ degree dew points should
yield 2000 to 3000 J/kg of MU CAPE across the warm sector this
afternoon/evening. Most recent CAM guidance suggests convective
initiation by late this afternoon into early evening near the
cold front across SE Nebraska into SW Iowa, with these storms
likely growing upscale relatively quickly into clusters or even
a well developed MCS and potentially moving into NE Kansas and
NW Missouri by late tonight, where up to 30 knots of deep layer
shear may be present. These storms could be strong to severe,
with damaging wind gusts being the primary hazard, followed by
large hail. Additional convective development is possible early
Saturday morning as the low level jet strengthens once more. The
most recent SPC Day 1 convective outlook highlights areas north
of a Leavenworth to Kirksville line within a slight risk for
severe weather, with a marginal risk for the remainder of the
CWA.

Warm and moderately moist conditions continue into Saturday and
Saturday evening, with WSW mid level flow continuing downstream
of yet another trough moving into the Desert Southwest and a
surface boundary draped across southern Iowa into SE Nebraska
and into northern Kansas. While portions of NE Kansas, NW
Missouri, and northern Missouri are within a marginal risk for
severe storms for Saturday afternoon into Saturday night, the
higher threat should remain to the north and northwest where
conditions will be more favorable.

The active pattern continues into Sunday, as an upper level
trough begins to eject across the Intermountain West with a
more subtle shortwave trough moving into the Central Plains.
This will result in deepening low pressure across eastern CO into
western KS with strengthening southerly flow and warm moist
advection south of a warm front lifting northward into the
Northern Plains and Upper Mississippi Valley. However, once
again the better severe weather setup looks to remain northwest
of our CWA across east central Nebraska, NW Iowa, SW Minnesota,
and SE South Dakota. That being said, strong to severe storms
cannot be ruled out for our area, especially for far NW
Missouri.

As we head into Monday, the mid/upper trough should take on a
negative tilt and eject across the central and northern Plains
with an impressive 70+ knot 500 mb SW oriented jet streak
developing over NE Kansas and into SW Iowa, with 50+ knot H5
flow overspreading much of our CWA. Very strong southerly low
level flow should be present Monday afternoon out ahead of an
approaching cold front, with sustained surface winds on the
order of 20 to 25 mph and gusts up to 40 mph. Temperatures are
projected to reach the lower 90s by mid to late Monday
afternoon, with continued moisture advection increasing dew
points into the upper 60s. This hot and moist airmass should
yield moderate to high instability, which will be paired with
strong deep layer shear thanks to the increased mid/upper level
winds overspreading the region, allowing for well organized
updrafts capable of producing severe weather. An increasing
southwesterly low level jet Monday evening/night should yield
higher SRH values thanks to increasingly cyclonically curved
hodographs in the low levels. Thus, all severe hazards will
likely be in play for Monday afternoon into late Monday night.
Unknowns at this time for our CWA include whether or not storms
can/will initiate in the open warm sector, the evolution/timing
of the surface boundaries, and how quickly storms will grow
upscale into clusters or a line of storms/MCS. In addition to
the severe threat, a plume of 1.6 to 1.8" PWATs will yield a
heavy rainfall threat, with WPC introducing a slight risk for
excessive rainfall for much of the CWA. Guidance remains varied
with respect to the timing of the frontal passage through the
region. If the cold front doesn`t move through until sometime
during the day on Tuesday, the severe threat could linger into
Tuesday.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 627 AM CDT Fri May 15 2026

A few light showers are ongoing west of IXD, but the terminals
should remain dry this morning outside of maybe a few sprinkles.
VFR conditions are expected to continue through at least late
evening, with southerly winds around 12 knots and occasional
gusts up to 18 knots this afternoon. There will be a chance for
showers and thunderstorms at STJ between roughly 6z and 9z
Saturday, and at the KC metro terminals between 7z and 10z
Saturday. It is possible that there could be brief VIS
reductions to MVFR if moderate to heavy rain were to impact any
terminal.

&&

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

&&

$$

DISCUSSION...BMW
AVIATION...BMW