St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

472
FXUS63 KEAX 102002
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
302 PM CDT Fri Jul 10 2026

.KEY MESSAGES...

- Continued severe storms during the afternoon/evening. Primary
  hazards include damaging winds, hail, and heavy rainfall.

- Flood Watch in effect tonight through tomorrow morning with
  heavy rainfall overnight. Some uncertainty remains owing to
  current activity influencing later potential.

- Drier, hotter weather through the weekend into early next
  week.

&&

.DISCUSSION...
Issued at 257 PM CDT Fri Jul 10 2026

Presently, a complex of storms is ongoing across northern MO. Very
efficient rainfall rates (up to 2-3 inches an hour) have been
occurring with this line of storms, and short-fuse hydrologic
products have been put out for the potential for flooding/flash
flooding along this line of storms. Overall progression of the
complex has remained slow during the late morning/early afternoon,
possibly owing to parallel upwind vectors/steering winds. However,
as the afternoon has progressed, the complex has become more
progressive with greater cold pooling within the stratiform
precipitation region towards the northwest. With ample instability
and sufficient effective shear, organized convection will continue
with an associated risk for severe weather. Already there has been a
downburst observed with the complex, and with stronger, organized
updrafts alongside efficient precip rates, the potential for
damaging winds/hail in association with precip loading is greater.

An outflow boundary has ejected out ahead of this complex of storms,
and is currently progressing to the southeast. Current meso-a shows
that the capping inversion has been effectively eroded off this way,
with high effective shear (40-45 kts) and no shortage of instability
(2000-2500 J/kg MUCAPE) as a result of quick clearing behind this
morning`s activity. Further destabilization is still possible out
ahead of this activity, with satellite imagery showing a slot of
clear air extending up towards Putnam/Schuyler counties. The
greatest confidence in a severe threat exists along this outflow
boundary as it provides lift within an unstable environment and
continues organized convective development through the remainder of
the afternoon into the early evening. However, if the outflow
outruns primary storms, their ability to remain surface based and
continue tapping into instability out towards the southeast will be
limited. Primary hazards with this activity will continue to be
damaging winds/hail and heavy rainfall. There is additionally
still some potential for discrete storm development within the
warm sector ahead of storms, but confidence in timing/placement
is not as high as with the ongoing activity.

Within the primary complex of storms, predominant storm motion
appears to be following environmental steering winds off towards the
east/northeast, with a tendril of higher reflectivity cores
developing outward along a nose of low-level WAA. As storms begin
following the environmental flow, the potential for training
convection lessens, but efficient rainfall rates will still lead to
heavy rainfall/localized hydrologic impacts. The ambient environment
still remains favorable for continued severe development (good
effective bulk shear/instability), which increases confidence in
this line continuing to impact northern Missouri through the
remainder of the day as convection remains organized. Primary
hazards remain damaging wind/hail with this complex.

Going into the evening/overnight, a signal for the development of a
band of storms across central Missouri still appears plausible.
There will be some influence from the residual outflow boundaries
from today`s activity that will dictate where convergence sets up
and prompts training convection overnight. With the environment
looking to continue remaining favorable for efficient precipitation
(PWATS 1.5-2", long skinny CAPE), have elected to go with a Flood
Watch for counties in central Missouri, with the thought that this
headline will need to be adjusted going into the evening with latest
guidance/better grasp on the evolution of the environment in the
short term. Deterministic guidance has been painting amounts of 1.5-
2" along this axis of precipitation, with low end chances (15-30%)
of exceeding 2 inches of total rainfall along this corridor.

Overnight activity looks to persist along the vort max of the
retreating upper-level trough. High PWATs near 2 inches, deep warm
cloud layers, and a vertical profile characterized by long, skinny
CAPE will continue to promote heavy rainfall with any remnant
activity, as well as lightning with residual MUCAPE. Despite greater
instability and better shear profiles residing further to the south
through the day tomorrow, residual instability could prompt stronger
updrafts in any organized convection, which could bring an
associated hazard of strong winds with any precip loading in
thunderstorms. The upper-level ridge situated over the western half
of the CONUS will build in behind the retreating trough, and provide
us with a drier forecast as activity is effectively blocked off
towards the south. Due to the position of the upper-level ridge over
the Plains as opposed to the southeast, we will not see the same
deep, sustained southerly flow as we did with our most recent heat
wave, limiting our humidity and keeping our heat indices lower.
However, even with lower heat indices, our high temperatures
reaching into the 90s through the early week will keep things
uncomfortable. The upper-level ridge looks to persist through late
in the week before it is gradually chipped away by embedded
shortwaves. However, late in the week, synoptic guidance has greater
deviation in their solutions of this breakdown in the upper-level
trough.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1230 PM CDT Fri Jul 10 2026

Challenging forecast at terminals this afternoon, with ongoing
weather near KSTJ and continued opportunities for weather at all
terminals into the evening. Looking at the potential for
discrete storms out ahead of a primary band of thunderstorms
moving closer to KSTJ, but knowing exactly when and where storms
will pop up is uncertain. Have elected to include PROB30s to
communicate potential for storms in the afternoon/evening, while
trying to time out wind shifts through the day. Will likely
need to amend as current activity alters the near storm
environment, as the forecast is highly dependent on this today.
Overall environmental winds are expected to shift northerly,
with indication of ceilings lowering into tomorrow morning.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Flood Watch from 7 PM CDT this evening through Saturday
     morning for MOZ044>046-054.
KS...None.

&&

$$

DISCUSSION...SPG
AVIATION...SPG