St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

842
FXUS63 KEAX 111137
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
537 AM CST Thu Dec 11 2025

.KEY MESSAGES...

* Light precipitation possible today across northern Missouri-
  though little in the way of accumulation is expected.

* Arctic airmass is expected Saturday.  Accumulating snow is likely
  across northern Missouri, setting the stage for subzero
  temperatures Saturday night as skies clear.  Light north winds
  could produce wind chills of -15 to -20 F across northeast
  Missouri Sunday morning.

&&

.DISCUSSION...
Issued at 415 AM CST Thu Dec 11 2025

Weak area of low pressure near Fort Peck Lake in eastern Montana as
of 09Z this morning is expected to build southeast throughout the
day. Warm front associated with this system is expected to lift
northeast across the region today leading to mild temperatures
roughly south of a line from Marysville to Booneville. Farther
north, temperatures will remain in the 30s.  As the mid level wave
build southeast, could see some light precipitation across Iowa
spilling into eastern Missouri potentially clipping Schuyler County
in northern Missouri.  With temperatures in the 30s and a dry sub
cloud layer, precipitation type is a bit of a question mark but
think column would evaporatively cool to largely support very light
snow. With that said, sustained saturation in the dendritic layer is
very limited. Best chance for snow is during the afternoon hours
today, but will be fighting dry air in the low levels.

Surface low is expected to track across the region tonight with
northwesterly flow developing behind the departing wave on Friday.
Temperatures on Friday are expected to be slightly below normal with
925 hpa temperatures -2 to -5 C yielding highs in the 30s.

A more dynamic set up this weekend as air from the Northwest
Territories plunges southward into the Central US.  The leading edge
of the arctic airmass provides adequate lift to lead to a
light-moderate snow event across northern Missouri. A band of
strong 750 frontogenetic forcing north of a line from Maryville
to Moberly is expected to develop on Saturday enhanced by a
kissing jet structure. As the arctic air build into the region,
the dendritic layer builds in depth from the surface towards 600
mb. This very efficient snow process will easily generate
accumulating snow across northern into eastern Missouri. LREF
ensemble is suggesting ~0.1- 0.2" of precipitation underneath
the band. Snow liquid ratios are currently 15-18:1, but with the
developing deep dendritic layer, the potential of seeing
20-25:1 ratios is there. This fresh snow cover will set the
stage for the coldest night of the season so far Saturday night
into Sunday morning. Currently, am forecasting sub- zero
temperatures over the fresh snow cover northeast of the KC
metro, but with 925 hpa temperatures plunging towards -15 to
-20C, widespread lows in the single digits looks likely. With
 the impacts of the fresh snow cover and the lingering light
 north winds, could see wind chills of -15 to -20 F across
 northeast Missouri.

A warming trend is expected Sunday into next week as upper level
ridge across the west builds east.  Temperatures are expected to
return above normal regionwide by Tuesday of next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 529 AM CST Thu Dec 11 2025

VFR conditions through most of the period. Mid level cloud
cover (6-10K feet agl) across the region will gradually clear
from south to north as a weak warm front lifts north . Mid
level clouds will remain northeast of a line from Maryville to
Booneville. As low pivots east of the area, could see MVFR into
IFR range build south mainly along and east of highway 65 after
06Z Friday.

&&

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

&&

$$

DISCUSSION...BT
AVIATION...BT