St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

298
FXUS63 KEAX 071142
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
642 AM CDT Mon Sep 7 2026

...12z Aviation Update...

.KEY MESSAGES...

- Hazardous and prolonged heat continues for portions of the
forecast area through at least Tuesday.

  - Extreme Heat Warning remains in effect through 8 PM Tuesday
    for Kansas City Metro and immediately surrounding counties.

  - Additional short-duration heat headlines may be necessary Tuesday
    as renewed heat briefly surges back across Missouri.

- Shower and thunderstorm chances return to the area Wednesday.
  This may include the potential for a few strong to severe
  storms.

&&

.DISCUSSION...
Issued at 349 AM CDT Mon Sep 7 2026

Storms yesterday evening and into the early overnight packed a
relative punch within an environment ripe for evaporatively enhanced
downdrafts. A number of areas experienced severe wind gusts and
associated wind damage. Also with relatively weak deep layer wind
profiles, outflows from storms resulted in chaotic storm motions. As
of early this morning, a few mainly elevated showers and non-severe
storms remain, predominantly associated with weak mid-level
shortwave activity and lingering outflow. These will generally
drift SE with the mid-level flow and gradually subside.

The stagnant / Omega Block pattern of late begins to shift and break
down today. This in response to a Polar Stream trough shunting the
New England cutoff low eastward and as that occurs, the western
portion of the Omega Block, the PNW cutoff low, will begin lifting
NE. More regionally, this too will push the mid-level ridge axis
back eastward out of the High Plains and toward the Missouri and Mid
to Upper Mississippi river Valleys. Unfortunately, that also means
well above normal temperatures continue for a bit longer, re-
surging/peaking on Tuesday. For today though, existing surface high
over the Great Lakes will keep winds out of the E/SE and should
yield temperatures a couple/few degrees cooler than seen Sunday. As
mentioned just previously, Tuesday sees resurgence of heat though as
winds become more southerly as the surface high shifts eastward and
the 850mb thermal ridge angles overhead. Tuesday likely sees highs
back to the mid 90s to 100 across the area. Given the current
headline orientation, Excessive Heat Warning for the KC Metro area
counties and areas W and S through Tuesday, an additional short-
duration headline may be necessary for surrounding areas to the
N/NE/E.

By late Tuesday, large scale pattern will take on a more zonal look
across most of CONUS. The previous PNW low will be situated over the
Canadian Plains along with its attendant surface low. More
importantly, the trailing cold front will be dropping southward
through the Dakotas and into Nebraska and Iowa by this time. This
allows more substantial relief to the area Wednesday as the cold
front continues to drop southward. Expect highs to fall back into
the mid 80s across northern Missouri. Some uncertainty lingers in
how quickly the front will drop south Wednesday, leading to high
temperature spreads in excess of 7 deg F south of Highway 36. This
too keeps the notion of a possible heat headline in play Wednesday
for southern areas where these wide spreads include the potential
for upper 90s to 100 and heat index values that would at least
approach Advisory criteria. Shower and storm activity is also
expected as the front drops through. The threat for severe storms
appears fairly muted with NBM SBCAPE probabilities of >1000 J/kg
widely 60 percent or less and supportive deep layer shear primarily
post-frontal. Some noted dry air in the lowest levels may yield some
wind potential though. The current SPC Day 2 and 3 Marginal Risks
over portions of the area feel appropriate. Relief overspreads the
entirety of the area by Thursday, with forecast highs ranging from
the low to mid 80s.

Large scale pattern looks to remain more zonal in nature through the
weekend and beyond, which will also allow additional periodic
chances for showers and storms. At this point, those chances appear
to be in the Friday/Saturday and Monday/Tuesday time frames as
deterministic and ensemble guidance depict shortwave troughs sliding
through.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 627 AM CDT Mon Sep 7 2026

General shower and thunderstorm activity has broadly weakened
and moved away from the TAF sites. With that in mind, the
resulting TAF period will be VFR with winds out of the SE
throughout the period in around the 8 to 12 kt range with the
occasional gust into the teens kts.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 8 PM CDT Tuesday for MOZ028-029-037-
     043-053.
KS...Extreme Heat Warning until 8 PM CDT Tuesday for KSZ025-057-060-
     103>105.

&&

$$

DISCUSSION...Curtis
AVIATION...Curtis