St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

366
FXUS63 KEAX 131046
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
545 AM CDT Mon Jul 13 2026

.KEY MESSAGES...

- A major warmup is forecast this week, with high temperatures
  well into the 90s expected by the end of the week.

- Daily peak heat index values near or just above 100 degrees
  are forecast Friday through Sunday.

- Significant rainfall is not expected over the next seven days,
  but there is small chance (15-25%) of showers during the heat
  of the day Wednesday and Thursday south of I-70.

&&

.DISCUSSION...
Issued at 209 AM CDT Mon Jul 13 2026

The forecast over the next week will be dominated by the omega
block that has set up over the CONUS. The region will be firmly
under the strong H5 ridging of the block, but the greatest H5
thickness anomalies will occur across the northern Rockies,
northern Great Plains, and northern Great Lakes today through
the middle of the week. The H5 height rises will reach the local
forecast area starting Wednesday, resulting in a significant
warm up for the latter half of the week. While H5 heights will
be near the 80-90th percentiles per the LREF (594-600 dm), H8
temperatures will only rise to the 60-70th percentiles (21-23C),
which should keep temperatures from getting to the extreme
values expected over the northern tier of the CONUS.

High temperatures today and Tuesday will reach typical July
values, in the upper 80s to lower 90s. Wednesday through Friday
will see temperatures creep into the lower to middle 90s. The
worst of the heat looks to be this weekend, where widespread
highs in the middle to upper 90s are currently forecast.
Ensemble guidance shows low-level specific humidity values
staying near normal values, so extreme humidity is not expected
to accompany the heat. Nevertheless, dew point temperatures in
the middle 60s to lower 70s combined with the heat will yield
peak heat index values in the upper 90s to lower 100s Friday
through Sunday.

While significant widespread rainfall is not forecast over the
next week due to the strong ridging, some Gulf moisture may
sneak northward into the lower MO River Valley. Combined with
some weakness along the southern edge of the ridge, this
moisture may be sufficient to trigger a stray shower/storm or
two for spots south of I-70 during the heat of the day Wednesday
and Thursday.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 545 AM CDT Mon Jul 13 2026

The TAFs are VFR. High pressure centered NE of the region will keep
winds steady from the E around 4-8 kts through the forecast period.
With elevated humidity levels continuing around the 925-850mb layer,
expect ongoing FEW CU development to persist. Cloud bases will be
around 5kft.

&&

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

&&

$$

DISCUSSION...Snyder
AVIATION...Snyder