St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

727
FXUS63 KEAX 141104
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
604 AM CDT Fri Aug 14 2026

.KEY MESSAGES...

- Dangerous heat continues for most areas today, potentially
  into Saturday. An Extreme Heat Warning remains in effect for
  areas generally along and south of the Missouri River today. A
  Heat Advisory remains in effect for area north of the warning
  through the Highway 36 corridor.

- Thunderstorm chances continue with the most likely corridor from
  the Missouri River northward to the IA/MO state line.

- Some relief to the heat is likely next week, in the wake of
  cold front.

&&

.DISCUSSION...
Issued at 229 AM CDT Fri Aug 14 2026

Upper-level ridging continues to be the dominant large-scale driver
of our weather resulting extreme heat. However, the forecast
area remains on the northern periphery of this ridge, which puts
mainly northern Missouri, into the path of convection. In the
mid-levels there is a plume of 14+C air at 700mb, extending from
southern Kansas through northwestern Missouri. Convection is
having a difficult time building eastward into that warm mid-
level air. At the surface, a boundary extends eastward along the
Highway 36 corridor with a pool of low-level moisture in the
vicinity of that boundary. This moistures is very shallow and
based of the latest aircraft soundings into MCI, there is ample
dry air aloft. Given the warm air aloft, the chance for
convection to occur along and south roughly a Kansas City to
Moberly is unlikely (<25%). For areas north of this, the
potential is greater and have generally arranged PoPs with this
in mind, with the greatest chances (20-35%) across the northern
portions of the forecast area. Instability will again be strong
to extreme across much of northern Missouri with 3500 to 4500
J/kg of SBCAPE. Stronger flow further north may also lead to
increasing shear with northward extent. Additionally, a fairly
robust shortwave/ internal PV anomaly, likely from the deep
convection over southern Nebraska and northern Kansas currently,
will be moving into this airmass later today. Given this, we
may see more robust/ potentially severe convection across
northern Missouri this afternoon and evening.

With regards to the heat for today, another day of high temperatures
in the middle to upper 90s can be expected south of a St Joseph
to Moberly line. A few areas in our south will also have
potential to see 100+ readings. In fact, most of Linn County, KS
has a greater than 50% chance of seeing 100+ degree
temperatures, with chances as high as 10-20% into the KC Metro.
With dewpoints ranging from the lower 70s in our south, the
upper 70s, across northern Missouri, heat index values will once
again be pushing 105-115, generally along and south of the
Highway 36 corridor. The current heat headlines look to be in a
good place and given the likelihood of seeing another day of
heat have extended the Excessive Heat Warning and the Heat
Advisory into Saturday. It`s possible these will need to be
adjusted depending on how the forecast plays out but confidence
was high enough to extend the current headlines.

A cold front will move southward through the area Sunday and that
should help to finally ease the extreme heat that has been affecting
the area. By Monday, temperatures should be about 10 degrees cooler
than the highs for Saturday. But dewpoints will also be 5-10 degrees
cooler as well. Beyond Monday, temperatures are more likely to be
closer to normal than to be well above normal like we saw this week.
Ensemble mean 500mb heights show the upper ridge suppressed and
centered over the Southwestern US. However, there are some
ensemble clusters (about 25-30% of members) that do have a
stronger and more Plains oriented ridge axis. So there is some
potential for temperatures to trend warmer as the forecast
evolves and updates with time.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 601 AM CDT Fri Aug 14 2026

VFR conditions are likely through the forecast. There are low
probabilities for storms this afternoon and evening. For now,
the chances a terminal sees a storm is low enough to keep any
mention out. North of STJ, the chances in crease as a strong MCV
over Nebraska slowly moves east and provides a forcing mechanism
for afternoon/evening convection from southeastern Nebraska
through Iowa and northern Missouri. Winds will be from the south
through the forecast with some gusts of 20-25 kts this
afternoon.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Extreme Heat Warning until 9 PM CDT Saturday for MOZ028>033-
     037>040-043>046-053-054.
     Heat Advisory until 9 PM CDT Saturday for MOZ011>015-020>025.
KS...Extreme Heat Warning until 9 PM CDT Saturday for KSZ025-057-
     060-103>105.
     Heat Advisory until 9 PM CDT Saturday for KSZ102.

&&

$$

DISCUSSION...CDB
AVIATION...CDB