St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

330
FXUS63 KEAX 161138
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
638 AM CDT Sat May 16 2026

.KEY MESSAGES...

- Active weather pattern continues into early next week.

- Strong to severe storms will be possible tonight, primarily
  across northern Missouri.

- Marginal risk for strong to severe storms on Sunday
  evening/night.

- Best chance for severe weather comes Monday afternoon into
  late Monday night. All severe hazards will be possible.

  - Locally moderate to heavy rainfall will also be possible.

- Hot temperatures expected today through Monday.

&&

.DISCUSSION...
Issued at 319 AM CDT Sat May 16 2026

Current H5 analysis shows a shortwave trough across the Upper
Mississippi Valley this morning. At the surface, a 1004 mb low
is analyzed over central Iowa, with a cold front extending to
the southwest into SW Iowa and SE Nebraska. Other than a few low
level jet driven showers across Linn County KS and Bates County
MO this morning, the CWA remains precipitation free. Additional
shower development may be possible later this morning, primarily
toward mid Missouri. For this afternoon, temperatures should
climb into the upper 80s for most locations, with 10 to 15 mph
southerly winds gusting up to 20 to 25 mph. An upper trough will
move into the western CONUS later today while the aforementioned
shortwave across the Upper Mississippi Valley moves across the
northern portions of the Great Lakes toward the NE CONUS. This
should yield slightly enhanced WSW mid level flow across the
Plains into the central CONUS. Meanwhile, the east-west oriented
cold front should remain across southern Iowa into SE Nebraska.
Convective initiation is possible by late afternoon in the
vicinity of this front across southern Iowa, with this likely
growing upscale rather quickly into clusters or even an MCS into
tonight. It is possible that convection could enter into
northern Missouri, and as such SPC has highlighted areas
generally along and north of US Highway 36 within a wind and
hail driven slight risk for severe storms. Additionally, with
the east-west boundary and the potential for training storms as
well as a corridor of 1.8 to 1.9" PWATs, there will be a heavy
rainfall threat. CAM guidance suggests that this should remain
north of the Iowa border, but again, cannot completely rule out
the threat for locally heavy rainfall creeping south of the
border into northern Missouri.

The active pattern continues into Sunday, as an upper level
trough begins to eject across the Intermountain West with a
more subtle shortwave trough moving into the Central Plains.
This will result in deepening low pressure across eastern CO into
western KS with strengthening southerly flow and warm moist
advection south of a warm front lifting northward into the
Northern Plains and Upper Mississippi Valley. However, once
again the better severe weather setup looks to remain northwest
of our CWA across east central Nebraska, NW Iowa, SW Minnesota,
and SE South Dakota. That being said, strong to severe storms
cannot be ruled out for our area, especially for far NW
Missouri. However, most recent CAM guidance keeps our CWA storm
free Sunday into Sunday night.

As we head into Monday, the mid/upper trough should take on a
negative tilt and eject across the central and northern Plains
with an impressive 70+ knot 500 mb SW oriented jet streak
developing over NE Kansas and into SW Iowa, with 50+ knot H5
flow overspreading much of our CWA. At the surface, a relatively
deep surface low should develop across western KS, with a cold
front extending to the northeast and linking up with a secondary
surface low across the Upper Mississippi Valley, and a dryline
extending southward into SW Kansas and into NW OK and the TX
Panhandle. Very strong southerly low level flow should be
present Monday afternoon out ahead of the approaching cold
front, with sustained surface winds on the order of 20 to 25 mph
and gusts up to 40 mph. Temperatures are projected to reach the
upper 80s by mid to late Monday afternoon, with continued
moisture advection increasing dew points into the upper 60s.
Convection should initiate in the vicinity of the surface low
and dryline across central Kansas and along the cold front
across NE Kansas, SE Nebraska, and into Iowa by mid to late
Monday afternoon with these storms approaching our CWA by late
Monday afternoon into Monday evening/night. With the hot and
moist airmass and steep lapse rates yielding moderate to high
instability and strong deep layer shear across our area, SPC has
highlighted much of the western and northwestern portions of
our CWA (including Kansas City) within an enhanced risk for
severe weather on the new Day 3 convective outlook. Large hail
and damaging winds should be the primary hazards, but tornadoes
will also be possible, especially later Monday evening as the
southwesterly LLJ ramps up and yields increasingly cyclonically
curved hodographs in the low levels. Some questions that remain
for our CWA are whether or not any storms will initiate in the
open warm sector out well ahead of the approaching front across
our area on Monday afternoon, the speed/timing of the
approaching front, and how quickly storms will grow upscale
into clusters or a line of storms as they approach our CWA from
the west Monday evening. In addition to the severe threat, a
plume of 1.6 to 1.8" PWATs will yield a heavy rainfall threat,
with WPC maintaining a slight risk for excessive rainfall for
much of the CWA. The severe threat may linger into Tuesday
toward mid Missouri depending on the exact timing of the frontal
passage, but the new SPC Day 4 has shifted the 15% risk area a
bit farther to the southeast (Rich Hill to Boonville and areas
south/southeast).

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 629 AM CDT Sat May 16 2026

Convection is ongoing south and east of the terminals as of
1130z this morning, but this should continue to move off to the
east. VFR conditions are likely to continue through the period.
Light and variable winds at the current moment should become
southerly and increase to around 12 knots around 15z this
morning. There may be a chance for showers or storms later
tonight, but for now confidence is not even high enough to
justify a PROB30 group.

&&

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

&&

$$

DISCUSSION...BMW
AVIATION...BMW