St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

989
FXUS63 KEAX 231846
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
146 PM CDT Mon Mar 23 2026

.KEY MESSAGES...

- The temperature roller coaster continues, with a quick warm-
  up through Thursday, followed by another sharp cooldown on
  Friday. Record temperatures are probable on Thursday (at least
  a 50 percent chance).

- A strong cold front will move through the region Thursday and
  Thursday night, bringing a chance (30 to 70 percent) of
  thunderstorms. Severe storms are possible (at least a 15
  percent chance).

- Fire-weather concerns may become elevated again after the
  cold-frontal passage, especially in areas that receive little
  precipitation from the system on Thursday night.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 139 PM CDT Mon Mar 23 2026

The forecast weather this week requires some marveling, as we
are truly in swing season. The relatively cool temperatures we
are experiencing today will be replaced quickly by warmer and
warmer temperatures Tuesday through Thursday. Forecast highs
jump a good 10 to 15 degrees daily through Wednesday and up to
record levels by Thursday (upper 80s to lower 90s). The reason
for this roller coaster is the presence of a highly anomalous
ridge to our southwest and our location on its northeastern
periphery, allowing us to be glanced occasionally by
southeastward-surging continental polar air via northwest-flow
perturbations. The ridge axis will progress eastward into the
Plains on Thursday in advance of the next stronger vorticity
maximum ejecting from the Rockies, bringing an exceptionally
warm day to much of the central U.S. in advance of a southward-
translating cold front from the northern Plains eastward to the
Northeast and Mid-Atlantic. Before then (i.e., through
Wednesday), the pattern simply loads up via southerly return
flow with highly stunted moisture return.

Most guidance keeps the front storm-free through Thursday
afternoon as it approaches the CWA, with stout capping via the
elevated mixed layer and ridge-related subsidence effects.
However, as large-scale ascent via the aforementioned vort max
reaches the central Plains Thursday evening, storms appear to
erupt quickly along the front. The pre-convective environment
will feature marginal to modest CAPE (500-1000 J/kg) and
sufficient deep-layer shear (35-45 kt) for organized
convection. The SPC Day-4 outlook includes a 15% risk area from
northeastern Missouri eastward, and recent machine-learning
convective forecasts outline much of our region in low
probabilities of severe weather given this setup. Think the main
question will be timing, with the strong capping likely
precluding convective initiation for much of the day. This could
allow the front to pass through much of the area dry
(especially if the faster model solutions verify). Of note,
models have been trending somewhat more aggressively with storm
coverage in our county warning area for this event (in part
owing to slightly slower frontal timing), with ensemble
consensus today featuring PoPs greater than 50% in much of our
area. Nevertheless, confidence is still low given several
limiting factors in place.

The other weather impact of note this period will be the
marginal fire-weather concerns during this warm-up, with daily
minimum relative humidity commonly nearing 30 percent or lower,
especially west of U.S. 65. Winds will be generally modest
through Thursday, but as the southerlies commence on Tuesday,
occasional gusts of 20 to 25 mph will certainly bring fire-
weather concerns upward, especially given our prolonged dryness
the past several months. Though green-up is occurring in much of
the forecast area, residual dry fuels and recent fire behavior
suggest conditions are still favorable for rapid fire spread if
more critical fire-weather conditions occur. The most concerning
day for fire weather in the short term is on Thursday, when
temperatures will soar into the 80s and 90s with wind speeds
approaching 20 mph (with higher gusts) in the afternoon. Even
with gradual moisture return, minimum relative humidity may
still reach 30 percent or lower.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
Issued at 139 PM CDT Mon Mar 23 2026

The main long-term concern is post-frontal fire-weather concerns
on Friday.

As the cold front passes through the region Thursday night,
storms are likely to shift southeastward from the area by
Friday. With much colder temperatures via strong north winds,
highs on Friday could be as much as 40 degrees colder than on
Thursday. However, dew points will crash upstream of the front
as well, leading to relative humidity below 30 percent in much
of the area by Friday afternoon. This will be most likely in
areas where precipitation is least likely in our region via the
front (far northeast Kansas and northwest Missouri), so another
day of near-critical fire weather may end up occurring Friday
afternoon in these areas.

Meanwhile, the upper pattern reloads into its very familiar
western-U.S. ridge/eastern-U.S. trough configuration next
weekend. As the central Plains will remain in the northwest flow
between the two, we face the sharp cooldown at the close of the
work week, followed by a quick warm-up during the weekend, with
temperatures in the 70s again by Sunday. Long-range models
suggest a considerably more active pattern the following week.
Perhaps we can shake this seemingly unshakable pattern as March
comes to a close.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 139 PM CDT Mon Mar 23 2026

A weak system will be moving through the region this afternoon
and tonight, bringing mid-to-high cloudiness and maybe a few
sprinkles. However, no impacts at the TAF sites are expected,
and predominant VFR is forecast through the period. East winds
around 10 kt this afternoon will become southeast tonight. A
primarily southerly wind will develop late Tuesday morning, with
a few gusts to 20 kt or so possible by midday.

&&

.CLIMATE...
Issued at 139 PM CDT Mon Mar 23 2026

Record High Temperatures:

March 25:
KSTJ: 83/1991

March 26:
KMCI: 85/1991
KSTJ: 89/1991

&&

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

&&

$$

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