St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

100
FXUS63 KEAX 241133
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
533 AM CST Wed Dec 24 2025

.KEY MESSAGES...

- Areas of dense fog and mist will persist across eastern Kansas
  and western Missouri through this morning. A dense fog
  advisory is in effect.

- More fog is possible tonight (up to a 70 percent chance),
  with the most favorable areas near and north/east of the
  Missouri River.

- Warm and dry weather will continue through Saturday.

- Much colder temperatures are expected to return to the region
  Sunday and Monday. Strong winds may occur on Sunday.

&&

.DISCUSSION...
Issued at 143 AM CST Wed Dec 24 2025

The forecast has become rather challenging the past couple of
days, owing to the presence of clouds/fog in this warm, moist,
and stagnant pattern. Where low clouds and fog persisted
yesterday, temperatures ended up about 7-10 degrees cooler than
those basking in more sunshine. This gives a pretty good idea of
just how much error may result in the temperature forecasts the
next couple of days, as cloudiness will be a significant
factor.

Models have trended toward cooler highs in the northern two-
thirds of the forecast area, a result of a natural "tightening"
of the forecast temperature gradient with time as models have
begun locking in on the development of a baroclinic zone within
the broader upper ridge encompassing much of the central CONUS.
A typical bias models exhibit is placing this baroclinic zone
too far north, and sure enough, that is what has been happening
the past several days for this mid-week period. Now, most
guidance is decidedly well below 70 for highs in KC the next
couple of days, and general consensus is near but below the
record highs at KC and St. Joseph today and tomorrow. However,
confidence is pretty low for a 1-day and 2-day forecast, owing
to the high sensitivity to sky cover. Low clouds and fog will
persist for much of the morning in the area, but fog should
diminish with time. The low clouds, on the other hand, may be
considerably more stubborn to scatter out. Model soundings keep
low-level saturation for much of the day in much of the area, so
the duration of stronger diurnal heating will likely be quite
limited. Warm advection will continue, however, so despite the
prevalent cloud cover, it will be warm. However, for the
northern CWA, it may end up being several degrees cooler than
yesterday, as cloud cover will likely persist much longer into
the day. On the other hand, it may be several degrees warmer in
the southern CWA (where cloud cover remained the longest
yesterday), owing to this region having the best chances to see
breaks in the clouds earlier in the day. The result is about a
20-degree spread in temperatures from north to south, a good
proxy for the models` trend for a stronger baroclinic zone (and
the ensembles` increased agreement in its location).

With the stagnant pattern continuing tonight, another round of
low clouds and fog seems probable for the region. HREF
probabilities of visibilities less than a half mile are around
40-70 percent in most of the CWA (especially north and west)
tonight. HREF has performed pretty well with the fog the past
couple of nights, so confidence is high we will see good
coverage of fog again tonight. However, there are a couple of
question marks. The first is the presence of antecedent cloud
cover from the daytime hours, which may act to prevent near-
surface saturation more readily (less nocturnal cooling). A
second question mark will be the presence of a weak perturbation
moving through the mid levels this evening. Passage of a
vorticity maximum tends to be a negative factor for fog
formation, often because lift above the surface tends to promote
low stratus rather than fog. Note that the clouds moving over
the region this morning have not prevented fog from forming, but
the density of the fog (as well as its consistency) have been
less than what was observed Tuesday morning. The current
forecast has widespread fog mention tonight, but confidence is
lower on the coverage of dense fog.

This allows for cloud cover to remain an issue on Thursday, as
yet another perturbation approaches the area. Combined with
persistent warm advection, it may be difficult for skies to
clear adequately to get prolonged insolation needed to take our
temperatures to record levels. In fact, most models are now
projecting temperatures on Thursday lower than those for today.
Highs in the 50s and 60s will be the consolation prize.

Models have been trending Friday and Saturday warmer. In fact,
these two days have the higher probabilities for the KC area
reaching 70 degrees now. A key factor in this forecast trend is
the passage of a stronger perturbation Thursday night across the
area, and this will bring a period of large-scale descent to the
area without bringing substantial cold advection. By Friday
afternoon, any cold advection ceases, but cloudiness is expected
to be far less prevalent. Think the records on Friday are in the
most jeopardy at this time. Confidence is lower with Saturday`s
temperatures, as a strong system will be approaching the area.
Large-scale ascent in advance will bring another round of clouds
Friday night and Saturday, so the temperature forecast becomes
more uncertain once again.

Models have trended the strong cold front moving through our
area this weekend slower. However, it will be moving through by
Sunday, and it will bring a brutal reality check to our warm
temperatures this week. Additionally, the strong surface high
building in upstream of the front will generate a strong
pressure gradient that will prompt a period of strong
north/northwest winds on Sunday. NBM probabilities for
advisory-level wind gusts on Sunday are already 25-50 percent in
much of the area, which is pretty decently high for a Day-5
forecast. Forecast highs on Sunday and Monday will be about
25-35 degrees lower than what we will see late this week.

One thing to watch with this slower trend with the cold front is
that it may allow sufficient moisture return in advance of the
front that precipitation generated by the front may begin close
to or even in portions of our forecast area on Sunday. For now,
the probabilities of this are low (less than 15 percent), but if
model trends continue, we may need to throw in some low PoPs for
the far southeast CWA on Sunday. Otherwise, the forecast is dry
through the middle of next week. Another reinforcing surface
high may move in around New Year`s Day, keeping temperatures
from rising too far above seasonal averages.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 528 AM CST Wed Dec 24 2025

Dense fog is affecting the KC metro terminals this morning and
is expected to continue (with potentially some variations
between MVFR, IFR, LIFR, and VLIFR) through at least 15z and
perhaps as late as 18z before VSBYs improve to VFR. CIGs may
have more trouble improving, perhaps taking most of the day
before becoming VFR. Confidence with timing of the changes in
categories is low, especially after 16z. Any VFR that can
develop late this afternoon or early this evening is expected to
deteriorate again as another round of low clouds and/or fog
develops. Restrictions are likely most of the night, especially
after 03z. East to southeast winds 5 to 10 kt will become south
or southwest this afternoon, but will slacken and become
variable quickly near/after 23z. Given the low-confidence
forecast, expect several TAF amendments today.

&&

.CLIMATE...
Issued at 157 AM CST Tue Dec 23 2025

Record High Temperatures:

December 24:
KMCI: 72/2021
KSTJ: 69/2021

December 25:
KMCI: 67/1922
KSTJ: 65/2019

December 26:
KMCI: 66/2008
KSTJ: 65/2008

Record High Minimum Temperatures:

December 25:
KMCI: 53/1936
KSTJ: 51/1936

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Dense Fog Advisory until 9 AM CST this morning for MOZ028>031-
     037>039-043>046-053-054.
KS...Dense Fog Advisory until 9 AM CST this morning for KSZ057-060-
     103>105.

&&

$$

DISCUSSION...CMS
AVIATION...CMS
CLIMATE...CMS