St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

026
FXUS63 KEAX 110716
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
216 AM CDT Fri Sep 11 2026

.KEY MESSAGES...

- Areas of dense fog this morning will dissipate within a few
  hours of sunrise. Dens fog is most likely from parts of west
  central MO into central and northeastern MO.

- There is a Marginal Risk for severe storms Saturday late
  afternoon into the overnight hours. Strong winds and hail are
  the primary threats with this activity.

- There is potentially an active pattern setting up for next
  week, with multiple chances for showers and storms leading to
  potential for heavy rainfall. There is considerable
  uncertainty in the placement dependent on how strong and upper
  ridge is to our southeast.

&&

.DISCUSSION...
Issued at 216 AM CDT Fri Sep 11 2026

A surface high, centered over the Great Lakes, combined with residual
moisture from yesterday`s rain, is leading to widespread dense fog
east of the KC area into central/northeastern MO, as of 07Z.
This may eventually spread westward into parts of west central
MO and east central KS by sunrise, given the weak pressure
gradient and calm winds. A Dense Fog Advisory has been issued
for areas east of Kansas City. Will monitor trends through the
early morning hours. If fog does build westward, a westward
expansion of the Dense Fog Advisory may be needed. Fog will
dissipate within a few hours of sunrise.

Focus then shifts to the potential for strong to severe storms
Saturday late afternoon into the overnight. Models show a shortwave
trough moving across Central Plains into the Midwest. This helps
push a front southward into the area which may lead to the
development of storms during the afternoon hours. This is uncertain
as while there is forecast to be ample CAPE, forecast soundings show
capping in place as the front passes through. If storms are unable
to develop during the day, the focus will shift to the
evening/overnight hours, where forcing associated with the nose
of the low-level jet will be key. Even with this, there is
considerable uncertainty as the placement of the nose of the
low- level jet and it varies by several hundred miles in the
available guidance. In the deterministic guidance, the NAM moves
the low- level jet over the forecast area. The GFS and the
ECMWF are much further west, in central to western KS. This is
beyond the time from the HREF and the LREF splits the difference
with the low- level jet across central KS. With how far east
the NAM forecasts the low-level jet, it is naturally the most
robust solution for the forecast area, tracking storms through
the forecast area through the overnight hours. Conversely, the
GFS and the ECMWF are further west, with the later showing
little in the way of QPF.

For next week, the pattern becomes favorable for near daily/nightly
precipitation chances across the Plains and Midwest. Our forecast
area is on the northern periphery of the upper ridging centered over
the Southeastern US. This effectively limits the southeastward
extent of precipitation chances. Stronger ridging shifts the best
chances northwestward. Weaker ridging allows for more of the
forecast area to see higher precipitation chances. The ridging
to the southeast will also help transport anomalously high
moisture northward into the region. And with the area being
persistently in the right rear quadrant of the upper- level
jet, there is a good signal for heavy rainfall in the region,
despite the uncertainty in its placement. As it currently
stands, the northern portions of the forecast have best chance
of seeing multiple rounds of storms with potential for
cumulatively heavy rainfall next week. Our current forecast
shows two to perhaps five inches of rain in far northern
Missouri next week. For the 48 hour period ending at 7 am
Thursday there is a 40-50% chance for at least 3 inches of rain.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1106 PM CDT Thu Sep 10 2026

Since the last TAF issuance, confidence has increased in dense fog
across western MO, with visibilities as low as 1/4SM at all
terminals (with the exception of KMKC at 1/2SM.) Visibility will
start to drop off around 08Z and will be lowest between 11-14Z.
Expect conditions to rapidly improve around/after 15Z, when
visibility should return to 6SM. Winds will be light and variable
throughout the period.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Dense Fog Advisory until 10 AM CDT this morning for MOZ015>017-
     022>025-030>033-038>040-044>046-054.
KS...None.

&&

$$

DISCUSSION...CDB
AVIATION...Shaw