St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

175
FXUS63 KEAX 271747
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1247 PM CDT Thu Aug 27 2026

.KEY MESSAGES...

* Warm conditions to close out the work week. Brief rain showers
  possible (15-30% chance) in far northeastern Kansas and
  northwestern Missouri during the early morning hours on Friday and
  Saturday.

* Heat and humidity building over the weekend and into early next
  week. Temperatures in the mid 90s and maximum heat index values
  around 100F will be possible.

* Nightly rain chances (20-30%) across far northern Missouri
  beginning Monday night through Thursday morning.

&&

.DISCUSSION...
Issued at 1245 PM CDT Thu Aug 27 2026

With high-amplitude ridging encompassing the western CONUS and a
trough axis nosing into the Mid-Atlantic, much of the Plains and
Midwest sits beneath northwesterly flow aloft. A trough looming over
British Columbia and the Pacific Northwest will march the ridge
eastward over the coming days. With the ridge nearing, expect warmer
but still seasonal temperatures in the mid to upper 80s today and
Friday. Early Friday morning, far northeastern Kansas and
northwestern Missouri could see some brief rain showers (15-30%
chance). Storms are expected to initiate in southern South Dakota and
northern Nebraska overnight with an enhancement of the low-level
jet. Some guidance has begun to depict an area of isentropic ascent
in southeastern Nebraska in the early morning hours. With convection
moving generally to the southeast in this northwest flow regime,
this localized area of isentropic forcing may be just enough to
sustain showers into the northern fringes of the CWA. A similar
setup on Saturday morning (just shifted slightly eastward) could
lead to additional rain across northern Missouri.

As the PNW trough slides east and compresses the ridge, high
pressure will eventually be corralled into Oklahoma and Texas over
the weekend. The tight pressure gradient along the ridge apex will
lead to strong southerly flow Saturday into early next week with
sustained winds around 10-15 MPH and gusts around 20-25 MPH. Daytime
cloud cover on Saturday may be able to abate some of the heat,
especially along and north of US-36. As such, maximum temperatures
in the north are expected to generally remain in the mid/upper 80s
again on Saturday. Further south, where confidence in cloud cover is
lesser, temperatures could break into the lower 90s. Even with cloud
cover, Saturday will feel warmer in comparison to the end of the
week with increasing moisture advection which will bring heat index
values into the mid 90s west of US-65. Increasing temperatures and
dewpoints Sunday through at least midweek will lead to several days
of temperatures in the 90s and maximum heat index values around 100F
areawide. HeatRisk is expected to reach Major (Level 3 of 4) Sunday
and continue for the majority of the area through Wednesday, further
signifying the potential for a late summer hazardous heat event.
Shower and storm chances will return just about nightly from Monday
night through Thursday morning. Showers/storms would likely be
focused along the nose of the low-level jet which is expected to
remain mostly north of Kansas and Missouri...a slight southerly
shift could bring these showers into our northern tier or two of
counties, so held onto about 20-30% 6-hourly PoPs during the
evening/overnight/early morning periods Monday through Thursday in
our far north.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1245 PM CDT Thu Aug 27 2026

VFR conditions are expected throughout the TAF period. Some fair
weather cumulus will persist until evening across the region. Winds
should remain light (around 5 knots) and northerly, shifting to
southeasterly Friday morning. Have a low chance (15-30%) for brief
showers in NW Missouri Friday morning. Some patchy fog may also be
possible near the Missouri River Valley early Friday morning.


&&

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

&&

$$

DISCUSSION...Macko
AVIATION...Shaw