St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

045
FXUS63 KEAX 101715
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1215 PM CDT Sun May 10 2026

...18z Aviation Update...

.KEY MESSAGES...

- Cooler today behind a cold front with temperatures warming
  Monday and Tuesday.

- Chance (15-25%) for showers and storms Tuesday
  afternoon/evening.

- Record high temperatures are possible on Friday.

&&

.DISCUSSION...
Issued at 230 AM CDT Sun May 10 2026

Current 500-hPa analysis shows ridging over the western CONUS
and troughing over the eastern CONUS continuing the northwest
flow pattern over the Central Plains. A subtle shortwave is
propagating through the troughing pattern over the Central
Plains and is helping to produce a few isolated high based
showers over the CWA. A modest dry layer in the low-levels is
making it difficult for any precipitation to reach the ground,
so have capped the chances for precipitation at just a few
sprinkles through the early morning hours.

A cold front passed through the area from north to south
yesterday leaving northerly winds in its wake. The CAA behind
the front will allow temperatures to fall into the low-to-mid
50s early this morning. The shortwave passing to the south of
the area will help keep a mid-level cloud deck in place across
central and southern MO through the day while northern MO will
see clear skies today. This will allow temperatures across
northern MO to be a couple degrees warmer (highs in the lower
70s) than further south where the lack of solar heating will
keep highs in the upper 60s.

The shortwave will clear the area by Sunday evening and large
scale subsidence on the back side will allow skies to clear
areawide. Surface high pressure then builds in over the Great
Lakes and winds turn southerly on Monday bringing the above
normal temperatures back to the area through the early portions
of the week. Highs on Monday are expected to be in the mid-to-
upper 70s with areas on the western periphery of the CWA pushing
towards 80F before temperatures climb into the low-to-mid 80s on
Tuesday.

Tuesday also brings the next chance for showers and storms as
another shortwave propagates through the large scale pattern.
The shortwave is progged to cross the Canadian Rockies Monday
night into Tuesday, inciting surface cyclogenesis in southern
Alberta. This system will primarily stay north of the CWA,
however, the cold front will cross the area on Tuesday as the
low tracks over the Great Lakes. Model guidance depicts some
instability developing ahead of the front in the afternoon, but
just how much depends on which model/ensemble you choose to look
at. The GFS/GEFS is by far the most aggressive with 1500-2000
J/kg of MUCAPE present through the mid/late afternoon while the
ECMWF/European ensemble and the Canadian show 500-1000 J/kg
over the same timeframe. Despite the discrepancies in
instability, all guidance is pointing to 35-45 kts of deep layer
shear, which will allow for any storms that are able to
initiate to be able to become well organized. Currently have
low-end chances (15-25%) for precipitation in the forecast given
the overall uncertainty surrounding this system. However, given
current model guidance, this seems like a favorable setup for
storms to form either ahead of or along the front Tuesday
afternoon/evening and is a day that is worth monitoring over the
coming forecast cycles. This thinking is reflected in the SPC
Day 3 outlook, which has the southern portion of the CWA in a
Marginal Risk (Level 1 of 5) for severe weather.

Behind the cold front, northerly winds will persist through
Wednesday bringing high temperatures down a few degrees from
Tuesday with highs expected to be in the upper 70s and lower
80s. The upper pattern is progged to begin to break down
towards the end of the week with the western CONUS ridge
flattening out and broad zonal flow becoming dominant. The
flattening of the ridge will lead to mid-level height rises over
the Central Plains, which combined with southerly flow due to
surface high pressure to the east will potentially push
temperatures into the 90s Friday through the weekend. However,
some uncertainty surrounds this as well.

The current forecast calls for highs on Friday to be in the
low-to-mid 90s with KMCI and KSTJ being forecast to be 2 degrees
above their record highs (91F in 1941 and 92F in 2017
respectively). However, model guidance depicts several
shortwaves moving through the zonal pattern, which could bring
precipitation (currently have a 30-40% chance Friday evening)
and cooler temperatures into play. The NBM shows a 50-70% chance
of exceeding 90F on Friday with the 25th and 75th percentiles
being 90F and 97F respectively. However, the LREF only shows a
20-30% chance of cracking 90F with the 25th and 75th percentiles
being 82F and 90F. All of this is just to say that there is
still substantial uncertainty in the late week and weekend
forecast and to stay tuned for future updates, which will
provide more clarity.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1212 PM CDT Sun May 10 2026

VFR conditions to prevail across the TAF sites. Mid-upper level
cloud cover will stream cross initial portion of the TAF period
with mostly clear to clear skies expected thereafter. Winds out
of the NE today will be modest at best with sites generally up
to around 10 kts and the occasional gusts to around 15 kts
possible. Light and variable into the overnight before settling
back out of the SW around/after 09z.

&&

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

&&

$$

DISCUSSION...Carothers
AVIATION...Curtis