St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

005
FXUS63 KEAX 171818
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
118 PM CDT Wed Jun 17 2026

.KEY MESSAGES...

- Severe thunderstorms are expected to develop this afternoon
  along a cold front moving southeastward through the region.
  The best chances for storms are south of a line from Kansas
  City to Kirksville. Large hail, damaging winds, tornadoes, and
  heavy rainfall are all potential hazards from these storms.

- Heat indices approaching/exceeding 100 degrees are forecast  this
  afternoon, especially south of I-70.

- Showers and a few thunderstorms are forecast again across
  west- central and central Missouri on Thursday. Severe
  weather is not expected.

- A strong storm system will move through the region this
  weekend, bringing another round of severe weather and heavy
  rainfall.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 110 PM CDT Wed Jun 17 2026

Current:

A strong low level jet is transitioning east this afternoon
with our gusty winds slowly decreasing. That being said, we are
still seeing wind gusts of 30-40 mph. This jet has also supplied the
region with ample amount of heat and moisture. Across the area we
have temperatures in the 90s with dew points in the 70s. This has
led to some areas seeing heat indicies in the triple digits.

This afternoon:

The focus of the afternoon will be our severe weather threat. With
the latest update from SPC we have an enhanced risk (level 3/5) for
our central and eastern counties with the metro and northwest MO
lowering to slight (2/5) and marginal (1/5). Convection is expected
to initiate off of a cold front moving across the region. As of
1 PM the current surface observations would indicated that the
boundary is draped through Holt and up through Worth. Areas
northwest of this boundary are not expected to receive showers
and storms. Ahead of this boundary we can expect a few
supercells to develop initially as mean wind flow runs
orthogonal to the boundary. As mentioned previously we have a
very warm and moist air mass out ahead of this boundary that can
be characterized as high instability (MLCAPE over 3000 J/kg)
and strongly sheared (bulk shear greater than 45 kts. Within
this environment supercells will be capable of producing large
hail (>2") and damaging winds (>75 mph). Veering winds ahead of
the boundary may also produce some streamwise vorticity for a
few tornadoes to develop. Later into the evening the cold pools
are expected to congeal with storm mode switching to more
linear. Threats will shift to damaging winds and a few
tornadoes. Best timing for severe storms still looks to be this
afternoon with CAMs showing a consistent signal for around
3-4PM. The cold front will then sag south through the evening
exiting the region after 8PM.

&&

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
Issued at 110 PM CDT Wed Jun 17 2026

Thursday/Friday:

The cold front will stall out over the Ozarks leading to a largely
quiet and pleasant day across most the region. Lingering mid
level moisture may interact with a weak impulse aloft to produce
some light rain and sprinkles through the day. The additional
cloud cover paired with the passage of the front the previous
day will keep the area cooler with highs in the upper 70s and
low 80s.

Surface high pressure will be shifting east through the day allowing
for southerly return flow. Temperatures will warm back into the mid
80s. Rain and a few storm chances (40-50%) will return overnight,
but the better chances for more widespread impacts arrive this
weekend.

Weekend:

Cross barrier flow sets up over the Central Rockies leading to lee
cyclogenesis on Saturday. This low deepens over eastern CO through
the day with surface high pressure being shunted off to the east.
This set up will allow for a strong gulf connection to develop
surging moisture back into the Midwest. Our PWATs increase to
2" which would put us over the 99th percentile of climatology.
The bountiful moisture will lead to heavy rain and flooding
concerns through the weekend and into Monday morning. NBM is
carrying PoPs of 20-40% through Saturday with chances increasing
to 50-80% overnight as the surface low encroaches from the
west. The systems warm front is expected to pivot in from the
west in the afternoon and evening hours increasing instability.
Pending placement of a shortwave crossing the midwest we would
see a boost in our bulk shear values sending increasing severe
potential.

Perhaps the bigger concern for the weekend will be the heavy
rainfall potential. WPC has the region highlighted in a slight risk
for excessive rainfall (2/3). Taking a stroll through the ensemble
plumes of both the GEFS and the Euro shows a high amount of spread
with the heaviest rainfall period targeted to be Sunday. The
Euro still favors heavier rain across IA and northern MO. The
deterministic GFS seems to be the outlier amongst even the GEFS
family showing upwards of 4". The rest of the members have
better clustering around the 1" mark. Given our antecedent
conditions we could see many of our rivers reach Minor to
Moderate flood stage by Monday morning.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1227 PM CDT Wed Jun 17 2026

Windy conditions to start the forecast period with southwest
winds gusts over 25 kts. A cold front will be dropping south
through this afternoon and evening with storms expected to fire
off this boundary. The latest high res guidance suggests that
the boundary will be on top of MKC or just south of the region
and progress south of the terminals after 22Z. Afterwards, VFR
conditions will persist through the remainder of the forecast
period with winds turning to out of the north and and northwest.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Wind Advisory until 3 PM CDT this afternoon for MOZ007-008-016-
     017-022>025-030>033-037>040-043>046-053-054.
KS...Wind Advisory until 3 PM CDT this afternoon for KSZ057-060-105.

&&

$$

SHORT TERM...Britt
LONG TERM...Britt
AVIATION...Britt