St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

841
FXUS63 KEAX 121758
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1258 PM CDT Thu Mar 12 2026

.KEY MESSAGES...

- Windy conditions are expected through early Friday morning. A
  wind advisory is in effect. Additionally, low relative
  humidity will lead to conditions favorable for rapid fire
  spread in relatively dry portions of northeast Kansas and
  northwest Missouri. A red flag warning is in effect through
  late Thursday evening.

- A northern-stream system may bring a brief bout of light rain
  or snow to far northern and northeastern Missouri Friday night
  into Saturday morning (less than 30 percent chance). Little or
  no meaningful impacts are expected.

- A strong storm system will affect the region Sunday and Sunday
  night. Very windy conditions are expected Sunday afternoon and
  night. Showers and thunderstorms may occur Sunday morning (up
  to a 50 percent chance), but chances for any severe weather
  are fairly low. Wraparound snow may occur with the system
  Sunday afternoon and evening, but confidence is very low on
  coverage, timing, and intensity. Stay tuned to the latest
  forecasts as details become clearer.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 1201 PM CDT Thu Mar 12 2026

A busy forecast for the short-term period, with dry and windy
conditions this afternoon/evening leading to fire-weather
concerns, a weak system glancing the northern portions of the
forecast area Friday night, and a strong and potentially quite
impactful system affecting the area on Sunday and Sunday night.

A strong surface low is moving through the northern Plains
today, attendant to a potent vorticity maximum progressing
rapidly east-southeastward on the heels of a deeper eastern
North America trough. A strong pressure gradient is developing
to the low`s south, bringing a lengthy period of strong
southwesterly surface winds to the central Plains this
afternoon/evening. Given the dry origins of this flow, very low
relative humidity will be observed through the evening hours.
With winds of 20 to 30+ mph and gusts to 45+ mph at times,
conditions are quite favorable for rapid fire spread in areas
that have seen little rainfall recently (northeast Kansas and
northwest Missouri). Red flag conditions have already begun in
these areas and look to be a slam dunk through the evening
hours. A wind advisory has also been issued for the entire CWA,
as HREF probabilities exceed 80% for wind gusts exceeding 45 mph
this afternoon and evening. It appears the peak winds may occur
during the evening hours, when the synoptically-augmented low-
level jet nocturnally increases in advance of trough passage.
The low-level jet may exceed 60-70 kt during the evening hours,
and if the near-surface profiles can remain well-mixed (which
is likely given the strong antecedent winds this afternoon),
occasional gusts above 50 mph can be expected.

Winds will gradually lower overnight but still remain quite
elevated as directions veer to a northwesterly direction by
Friday morning. Cold advection will lead to a slightly cooler
day Friday, but the progressive upper flow will allow for a
quick transition to a neutral and then warm advection regime by
Friday evening. Conditions should be dry through Friday.

The aforementioned warm advection on Friday evening is expected
to generate an area of light precipitation to our north Friday
night into Saturday morning. This appears most favorable in
South Dakota, southern Minnesota, Nebraska, and Iowa; however,
the northwest upper flow may allow some progression of the
precipitation southeastward into far northern Missouri. Longer-
range MPAS CAMs are indicative of this potential Friday night,
with low-level thermodynamic profiles favorable for snow if the
timing of the precipitation is late in the overnight hours.
Overall, this potential is low for our forecast area (less than
20 percent) and confined to our far northern Missouri counties.
However, we will keep an eye on model trends here in case
lighter precipitation is able to generate and progress farther
south. Any precipitation amounts would be light, however.

After a period of transient ridging on Saturday (bringing
another day of warm temperatures...highs in the upper 60s to low
70s), a strong system rapidly digging through the Rockies on
Saturday will approach the region Saturday night and Sunday. By
Sunday morning, a sub-1000-mb surface low is expected to develop
in the central Plains, with strong large-scale ascent leading to
a break-out of precipitation within the warm sector and on the
north side of the system (eventually wrapping to the west side
of the surface low). Models are all over the place here, though,
with the faster models basically preventing wraparound
precipitation (snow) from reaching our forecast area before the
low moves too far east of the region. The slower models,
however, give us a several-hour period of wraparound snow, with
temperatures crashing on the upstream side of the system and
very strong winds. Ensemble probabilities of advisory-level
winds are already 50-80 percent Sunday afternoon and evening,
which is contextually quite high this far in advance (signifying
high confidence). But the very different surface low evolutions
make the precipitation forecast much more challenging. That
said, NBM probabilities of measurable snow Sunday
afternoon/evening generally exceed 50 percent across the CWA
(and are mostly 70-90 percent). Probabilities for advisory-level
snow (roughly 2 inches) are generally 25-50 percent west of
U.S. 65 and 35-65 percent east of U.S. 65. In other words,
meaningful snow is on the table with this system, and combined
with the winds, could be fairly impactful. With such a wide
variety of outcomes possible with this system, it is wise to pay
attention to subsequent forecasts as details inevitably become
clearer.

Another potential with this system is warm-sector showers/storms
Sunday morning. Thermodynamic profiles show decent CAPE in the
warm sector (500-1500 J/kg). If convection can initiate Sunday
morning (before the synoptic front moves through the area), it
is not completely out of the question a strong or severe storm
occurs given very strong deep-layer shear in place. Temperatures
aloft will be cold, so small to marginally-severe hail appears
to be the main threat with any storms that can develop. However,
think the overall severe potential is much higher to our south
and east.

Any wraparound snow on the cold side of the system is expected
to exit the region Sunday night, with winds gradually subsiding.
The incoming cold will be a shock to the system, with
temperatures crashing during the day Sunday and being well below
freezing Sunday night (lows potentially in the single digits
and teens). If you can believe it, wind chills near or below
zero are in the cards Sunday night and Monday morning.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
Issued at 1201 PM CDT Thu Mar 12 2026

After a cold day Monday and another cold night Monday night
(highs in the 20s and 30s; lows generally in the single digits
and teens), upper ridging should translate slowly eastward into
the central U.S. by the middle of next week. Some models are
showing a weak perturbation in the predecessor northwest flow
Tuesday and Tuesday night, with chances of light precipitation
(rain or snow, depending on how cold temperatures get Tuesday
night and the timing of the system overall). However, the
general trend should be warmer and drier with time, as the high-
amplitude and large ridge becomes more and more anchored to the
western and central U.S. Long-range models have highs well into
the 70s by late next week. Our bout of winter late this weekend
should be mercifully brief.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1201 PM CDT Thu Mar 12 2026

Windy conditions are expected at the terminals this afternoon
and evening, with southwest winds of 20 to 30 kt, gusting to 40+
kt at times. Winds will gradually veer to westerly by 06z
Friday and northwesterly after 09z. Speeds/gusts will gradually
lower after 06z as well, though winds of 10 to 20 kt with gusts
25 to 30 kt may continue through the overnight hours and even
through Friday morning. VFR is expected through the period.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Red Flag Warning until 9 PM CDT this evening for MOZ001>004-
     011>013-020-021-028.
     Wind Advisory until 2 AM CDT Friday for MOZ001>005-011>014-
     020>022-028>030-037.
     Wind Advisory until 4 AM CDT Friday for MOZ006>008-015>017-
     023>025-031>033-038>040-043>046-053-054.
KS...Red Flag Warning until 9 PM CDT this evening for KSZ025-102-
     103.
     Wind Advisory until 2 AM CDT Friday for KSZ025-102>105.
     Wind Advisory until 4 AM CDT Friday for KSZ057-060.

&&

$$

SHORT TERM...CMS
LONG TERM...CMS
AVIATION...CMS