St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

864
FXUS63 KEAX 270912
AFDEAX

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

.KEY MESSAGES...

- Seasonably warm with relatively low humidity today and
  tomorrow.

- Above normal temperatures arrive on Saturday, with humidity
  gradually increasing through the weekend and into next week.

- Hot and moderately humid conditions expected for Sunday into
  the middle of next week, with maximum afternoon heat index
  values in the upper 90s to around 100 degrees.

&&

.DISCUSSION...
Issued at 312 AM CDT Thu Aug 27 2026

Current H5 analysis shows a 598 dam H5 high centered over the
Desert Southwest with associated high amplitude ridging
extending north all the way into northern Alberta and
Saskatchewan. To the east of this, a mid/upper trough is in
place from Ontario southward into the Ohio Valley. Our CWA
remains beneath northwesterly flow aloft between the western
ridge and the east/northeastern trough. Meanwhile, at the
surface, the weak cold front that moved through the region
yesterday has stalled over the Ozarks, with a 1020 mb high
sliding into eastern Nebraska. This has resulted in mostly clear
skies and calm winds this morning, with temperatures in the
60s. The synoptic scale pattern remains generally the same
throughout the day today. High temperatures this afternoon
should range from the lower 80s across far NE Missouri where the
upper trough will have more influence, to as warm as the upper
80s to 90 degrees for areas south and southwest of the KC metro
where H5 heights will be higher closer to the western ridge. Dew
points should reside in the upper 50s to lower 60s, keeping
conditions comfortable. By tomorrow, an upper trough is progged
to come across the northern Pacific into British Columbia and
the Pacific Northwest, which will help push the upper ridge axis
a bit further east, with higher H5 heights creeping in from the
west. This should yield temperatures a couple degrees warmer
for Friday afternoon, but dew points in the upper 50s should
keep conditions relatively comfortable once again.

The upper trough across the PNW continues to push eastward into
the Intermountain West on Saturday and into the Northern High
Plains by Sunday, with the H5 low deepening and an accompanying
surface cyclone developing. This will flatten the upper ridge
and push the center of the H5 high over Texas and Oklahoma,
sending temperatures into the low to mid 90s on Saturday and
mid 90s on Sunday. This will also usher in increased southerly
low level flow, with south winds on the order of 15 to 20 mph
and gusts up to 25 to 30 mph for Saturday and Sunday afternoons,
and will yield modest moisture return, with dew points
returning to the low to mid 60s. The closed H5 low is progged to
move across southern Saskatchewan into central Manitoba on
Monday and toward the Manitoba/Ontario border by Tuesday,
pushing a cold front across the Upper Midwest. Modest moisture
return should continue, with dew points increasing to the mid
60s by Monday afternoon and upper 60s by Tuesday afternoon. With
increased moisture and some weak forcing for ascent, chance
PoPs returning to the forecast Monday morning (20 to 30%) and
again on Tuesday morning (20 to 40%), primarily for areas north
of Interstate 70. Otherwise, expect hot and moderately humid
conditions to continue for Monday through Wednesday, with highs
in the mid 90s and max heat index values in the upper 90s to
perhaps low 100s for most locations.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1141 PM CDT Wed Aug 26 2026

High pressure will keep skies mostly clear during the overnight
hours. Some areas of fog may develop. Of the TAF sites, STJ may
fill in with fog in the river valley. Unsure if dense fog will
develop in area outside of river valleys through Thursday
morning.

&&

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

&&

$$

DISCUSSION...BMW
AVIATION...Krull