St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

479
FXUS63 KEAX 160904
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
404 AM CDT Thu Apr 16 2026

.KEY MESSAGES...

* Strong to severe storms anticipated Friday, including greater
  confidence in the severe threat compared to recent days/events.

  - All hazards possible, including tornadoes but especially
    large hail and damaging winds

  - Current timing looks to be from early/mid afternoon into
    evening, similar to timing to what transpired
    yesterday/Wednesday

* Temperatures remain seasonally warm (mainly 80s) through
  Friday, then much cooler Saturday. Gradual warming after
  Saturday.

&&

.DISCUSSION...
Issued at 401 AM CDT Thu Apr 16 2026

After the widespread strong to severe storm event yesterday/Wednesday
afternoon and evening, quieter conditions have settled into the
area. The parent upper level shortwave trough and attendant
surface low have shifted east of the area, continuing to fire
off non-severe convection toward the Mid-Mississippi and western
Ohio River Valley areas. Locally, easing of surface pressure
gradient and deep layer subsidence have resulted in much lighter
winds (near calm in some cases) and clearing skies. For today,
conditions remain quiet with mostly sunny skies and notably
lighter southerly winds continuing. Unfortunately, the quiet and
calm will be short lived...

The next weather maker/upper trough has moved into the PNW and will
continue to dig down into the mid-Mountainous West through the day
today. As it does so, rounds of Lee Cyclogenesis will be seen over
the northern High Plains. Coupled with broad surface high over the
SE US and increasingly SW mid-upper level flow, much of the central
CONUS will see increasing deep moisture return by late
Thursday/overnight and especially into early Friday. By Friday
morning, deep upper trough begins to kick out/pivot into the Plains
and take on a more neutral to slightly negative/mature tilt, which
very typically favorable for severe weather scenarios, and a jet
rounding its base and nosing into the forecast area. Broad set of
synoptic guidance (deterministic and ensemble) have depicted this
setup for days now, including various AI/ML/NN aided guidance
further ringing the bell. As we too have begun to enter hi-res
windows, guidance remains pretty well locked in with the severe
threat, seen in HREF and HRRR NN among others.

Okay... so about what about the details, primary threats, timing,
etc? Aforementioned general synoptic setup is yielding at least
moderate, if not high, confidence in the following: substantial
SB/MUCAPE values of 3000-3500 J/kg, weak or no cap by the afternoon,
increasing deep layer shear >50 kts 0-6km, notable increasing low
level shear of >35-40 kts 0-3km, and elongating hodographs among
other things. Of note, and something that does introduce some
uncertainty is frontal position and timing. This will not only be
important for general threat area, but also initial storm modes and
just how supportive the environment will be for higher storm
potential. Effectively, it may be a bit of a race for the low-mid
level flow increase ahead of the frontal passage. Currently,
forecast suggests a "a just right" sort of timing with front
entering NW forecast area mid-late afternoon Friday and that
increased low level flow overspreading the area at that time. As a
result, we may have both discrete supercells in the open warm sector
(depicted very weak or nil cap) concurrent with increasing
activity/initiation along the cold front. Should this prevail, all
modes of severe weather are absolutely in play. Tornadic activity
most likely discrete cells, but increasing 0-3km shear semi-
orthogonal to the front too would keep QLCS tornadic activity in
place. Damaging winds and hail would be expected to be prevalent
given the CAPE-shear parameter space. Largest hail with discrete
activity, but severe hail also in play within more plusey multi-
cell/clusters or linear storm modes. Damaging winds may be the
highest end and most prevalent threat given the expectation for a
rapid uptick convection coverage. Whether discrete, multi-cell, or
linear. Mean-winds and right movers will yield storm motions >45
mph, so it would not take much more to get base severe winds. Given
the large CAPE/steep lapse rates and favorable shear/wind profile
orientations, organized cold pools (discrete or linear) could
certainly produce swaths of 70-80+ mph winds. All of this looks
to transpire from early afternoon to evening, not unlike the
timing seen yesterday/Wednesday. To no surprise, SPC Day 2
Outlook reflects a lot of this thinking with Sig 1 Hatching and
quite elevated probabilities for Hail/Wind, at minimum the
highest of our recent events. Suffice it to say, pay attention
to remaining evolution of details for Friday.

As this sizable trough sweeps through the central CONUS, much
quieter and cooler conditions prevail through the weekend as NW flow
at the surface and aloft prevail. Highs fall back into the 50s for
most Saturday, then gradually warming thereafter as mid-upper level
ridging begins to work through the west and eventually central CONUS.
Any notable precipitation chances then look to hold off until at
least mid-week if not end of next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1136 PM CDT Wed Apr 15 2026

VFR conditions are likely (>80%) through the forecast. There is
a low chance (<20%) for some lower clouds and/or minor fog to
develop generally south of the Missouri River early tomorrow
morning, before dissipating with daytime heating/ mixing.
Otherwise, winds will be light/ variable overnight and then
increase late tomorrow morning out of the south. Sustained winds
around 10kts are expected with some occasional stronger gusts to
20kts likely. Winds then diminish and back to the southeast
after sunset.

&&

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

&&

$$

DISCUSSION...Curtis
AVIATION...CDB