St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

624
FXUS63 KEAX 301122
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
622 AM CDT Tue Jun 30 2026

...Updated Aviation Discussion...

.KEY MESSAGES...

* Hazardous heat threat continues. An Extreme Heat Warning will
  remain in effect through 9 PM Friday evening.

* Most areas to remain dry throughout the week. Northwestern
  Missouri has a low chance (15-25%) of seeing rain/storms
  midweek. Otherwise, the best chances for showers and storms
  arrives late Saturday into Sunday morning (currently 30-50%
  chance).

&&

.DISCUSSION...
Issued at 234 AM CDT Tue Jun 30 2026

In the near term, the forecast remains largely unchanged.
Domineering high pressure over the eastern CONUS and our position
beneath the ridge will allow for at least several more days of
dangerous heat across the region. Strong southerly flow and moisture
advection has resulted in dewpoints surpassing the forecast values
by 3+ degrees in some areas both Sunday and Monday. Thus, the
primary heat-related forecast update involved a bump in forecast
dewpoints, but even with this change, heat indices are still widely
on track to fall near or within the 105-110F range today. An Extreme
(Level 4 of 4) HeatRisk "bullseye" still sits over central Missouri
and extends slightly westward toward US-65, with Major (Level 3 of
4) HeatRisk elsewhere.

With the ridge expected to hold firm, the Extreme Heat Warning will
remain in effect through Friday evening. During this stretch, most
will stay dry. A surface cyclone which has brought severe weather to
the Northern Plains is expected to continue lifting north into
Canada while a trough amplifies near the California coast. In the
coming days, this trough is expected to eject a series of shortwave
impulses through the flow, allowing for additional storm chances
across the Plains and Upper Midwest. Some convection may be able to
dip into far northwestern Missouri late Wednesday/early Thursday and
again late Thursday/early Friday, but probabilities remain low with
both opportunities (only a 15-25% chance). The best chance for any
widespread rain or convection does not arrive until Saturday when a
shortwave rushes towards the Mid-Missouri Valley. Mid/long-range
guidance does indicate some degree of frontogenetic forcing Saturday
evening and early Sunday morning, but disparities remain
(positioning, strength, timing, etc.). Likewise, there are questions
about the quality of instability and deep-layer shear in this
timeframe. Regardless, this still appears to be the greatest shot we
have at meaningful precipitation this week, coming in at a 30-50%
chance areawide. Additional details should be ironed out in future
forecast iterations.

Hot and humid conditions are expected to continue into the weekend
and the early portions of next week as ridging rebuilds over the
central CONUS. While this timeframe does not look quite as
concerning as the present heat event, it will warrant the close
monitoring of trends in the coming days.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 620 AM CDT Tue Jun 30 2026

High pressure will continue to keep conditions dry and skies
VFR. Breezy S/SSW winds will continue through the day today,
gusting up to about 28kts. This evening, winds will begin to
relax.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 9 PM CDT Friday for MOZ001>008-
     011>017-020>025-028>033-037>040-043>046-053-054.
KS...Extreme Heat Warning until 9 PM CDT Friday for KSZ025-057-060-
     102>105.

&&

$$

DISCUSSION...Macko
AVIATION...Wilson