St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

711
FXUS63 KEAX 081100
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
600 AM CDT Thu Oct 8 2026

.KEY MESSAGES...

- Well above normal temperatures will continue through the weekend
  and into at least the next week.

- Rain chances return for the middle of next week.

&&

.DISCUSSION...
Issued at 218 AM CDT Thu Oct 8 2026

The boundary that moved through Wednesday has stalled to our south
and is evident from southwestern Missouri west-northwest into
northwestern Kansas. As high pressure moves southeastward into the
Great Lakes, weakening as it does so, low-level flow will increase
from the south across Kansas and to a lesser extent western
Missouri. This will lift that stalled boundary back northward
through the day so that by around 21Z, it will be situated from
eastern Nebraska southeast into central Missouri. Moisture may
pool again along this boundary as it is lifting northward and
with temperatures likely to climb into the low to mid 80s again,
dewpoints may climb into lower 60s. So it will once again feel
hot for anyone outside this afternoon. Our normal high
temperatures today range from the upper 60s, in northeastern MO,
to near 70 degrees, in the Kansas City area. So we`ll once
again be looking at highs at least 10-15 degrees above normal,
with some areas pushing 20 degrees above normal.

As has been the case for a few nights now, models show an area
of ascent developing as the low-level jet strengthens tonight
into Friday morning. This ascent is fairly deep, evident from
300K to 310K. So showers storms seem likely for areas to our
north. Forecast soundings for northern and northeastern Missouri
show deep dry air below 10000 to 12000 feet. With the strongest
ascent north of the area and deep dry air to overcome, it`s
very unlikely anything develops or moves into our northern zones
tonight. So the forecast remains dry with only ~5% PoPs for our
far northern zones.

The forecast through Monday continues to look well above normal
We`re very likely to see highs continue to be 10-15 degrees above
normal, with some areas, mainly in our southern and southeastern
zones, pushing 20 degrees above normal. High temperatures will
be pushing the lower 90s in our southern and southeastern zones
given the dominant upper ridging across the middle of the
country. Within this ridging though, the remnants of Isaias will
pass to our east, aided by a strong shortwave moving through
the Southern Plains. The upper ridge reestablishes itself and
amplifies across the middle of the country through the middle of
the week. Ensemble mean 500mb heights are greater than the 90th
percentile. If this verifies, our highs will be right back in
the mid to upper 80s, and pushing 90 degrees, well above our
current forecast. Forecast uncertainty is very high and the
spread between the 25th and 75th percentiles is around 15
degrees across the area. This increase to greater than 20
degrees comparing the 10 and 90th percentiles. This uncertainty
naturally spills into the PoP forecast as well. If the upper
ridging is stronger, like the deterministic GFS shows, and the
ensemble 500mb mean indicates, the chances for precipitation
decrease substantially for Tuesday into Wednesday. If we see
something more in line with the deterministic Canadian, which
has a shortwave moving through, or the deterministic ECMWF,
which has the ridge further east, we would have better chances
for rain.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 600 AM CDT Thu Oct 8 2026

River valley fog will affect STJ for a few hours after sunrise.
Otherwise VFR conditions are expected for eastern KS and western
MO. Winds will be light through the forecast though will trend
to the southeast later this morning.

&&

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

&&

$$

DISCUSSION...CDB
AVIATION...CDB