St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

492
FXUS63 KEAX 091810
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
110 PM CDT Sun Aug 9 2026

.KEY MESSAGES...

* An Extreme Heat Warning is in effect for far east-central Kansas
  into central Missouri until Wednesday evening.

* A Heat Advisory is in effect for areas generally north of I-70
  until 8PM tonight. Confidence in reaching criteria over the next
  few days is lower due to rain potential and cloud cover, so taking
  a day-by-day approach to heat headlines.

* Overnight showers and storms possible (10-30% chance) nightly
  tonight through Wednesday morning, primarily across
  northeastern Kansas and northern Missouri. More widespread
  rain chances return overnight Wednesday and Thursday (50-60%
  chance north of I-70).

&&

.DISCUSSION...
Issued at 337 AM CDT Sun Aug 9 2026

Early morning showers and storms persisted later than anticipated
courtesy of an area of isentropic lift stretching from our southwest
into our northeast. Cloud debris has abated some of the heat, but
even so, temperatures are expected to continue rising into the
low/mid 90s this afternoon with heat indices above 100F for the
majority of the area. Areas north of I-70 and near the MO/KS border
may be able to realize heat indices of 105F or greater having
received more solar heating so far today. Though the heat expected
south of I-70 today is less intense than previously forecast,
several locations are still on track to see heat indices around 105F
with multiple more days of oppressive heat to come as the ridge
builds overhead. Gusty southerly winds are expected to persist until
sunset tonight before the pressure gradient shifts southward. There
is some indication of breezy conditions continuing tomorrow, though
with a less impressive gradient.

Currently, the only heat product that extends beyond this evening is
the Extreme Heat Warning for far east-central Kansas into central
Missouri. North of I-70, confidence in reaching Heat Advisory
criteria is lower. Several shortwaves are expected to pass
through the region or just to the north over the coming days,
mainly during the overnight and early morning hours. Timing is
such that these shortwaves would also receive support from the
low-level jet as it noses into southern Nebraska and Iowa.
Moreover, these features will be interacting with a surface
boundary bobbing between the I-80 and US-36 corridors between
now and Wednesday morning. These fluctuations introduce some
uncertainty as to where showers/storms may be able to develop,
but even if development occurs to our north, northwesterly
mid/upper-level flow may help guide showers/storms into the
northern portions of the CWA almost nightly. Some storms may be
capable of producing strong winds with northern portions of the
CWA highlighted in an SPC Marginal Risk (Level 1 of 5) for
severe weather both tomorrow and Tuesday. Even though the
probability of showers and storms is low through Wednesday
morning (only a 10-30% chance across northern MO), circumstances
not too dissimilar from this morning could limit the amount of
insolation and consequently prevent portions of the area from
reaching Heat Advisory criteria.

Wednesday, the surface boundary is expected to slide to the south as
a cold front before stalling in the vicinity of the I-70 corridor.
Where exactly the boundary stops will have implications for
temperatures on Thursday. On the north side, temperatures are likely
to be in the upper 70s to low 80s compared to the low/mid 90s on the
south side. Precipitation chances will also increase as the boundary
sinks south, with a 50-60% chance of showers/storms north of I-70
late Wednesday night into early Thursday morning.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 107 PM CDT Sun Aug 9 2026

VFR through the period. Clear conditions and breezy southerly
surface flow with gusts up to 25 knots possible through sunset.
High clouds to build back in overnight.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory until 8 PM CDT this evening for MOZ001>008-
     011>017-020>025-028>033-037-038.
     Extreme Heat Warning until 8 PM CDT Wednesday for MOZ039-040-
     043>046-053-054.
KS...Heat Advisory until 8 PM CDT this evening for KSZ025-102>105.
     Extreme Heat Warning until 8 PM CDT Wednesday for KSZ057-060.

&&

$$

DISCUSSION...Macko
AVIATION...Macko