277
FXUS63 KEAX 130519
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1119 PM CST Fri Dec 12 2025

.KEY MESSAGES...

- Light Snow Accumulation North-Central Missouri

- Below Zero Wind Chills Arrive Late Saturday Night through Sunday
  Morning

- Warm Up Through Next Week

&&

.DISCUSSION...
Issued at 241 PM CST Fri Dec 12 2025

Amplified H5 ridge axis currently sits over the Pacific just off the
west coast of the CONUS, with strong northwesterly flow oriented
from British Columbia into the western Ohio River Valley. Objective
analysis as of 20z is showing a strong 120+ KT jet streak at 300mb
pushing across Iowa into Western Illinois, with 100 kts hitting our
northeast counties from Kirksville and northward. This is steering a
strong surface anticyclone out of Canada, and 20z objective analysis
indicates this feature is centered over the northern High Plains,
but surface pressure rises extend into the eastern Plains. A strong
Arctic Airmass is associated with this strong anticyclone, and there
a few notable thermal boundaries associated with this. The first one
is a notable temperature and wind shift, that is currently moving
through eastern Iowa, and its trailing edge may get northern
Missouri resulting in some scattered flurry activity as the evening
progresses. But overall, this first boundary will be fairly
uneventful for our forecast area. Surface anticyclone pushes into
the North-Central Plains of the Dakotas during the overnight hours.

Saturday, another cold front gets pushed ahead of the surface
anticyclone. A lobe of vorticity swings around the backside of an H5
closed-low system over the Northern Great Lakes Region, that will
provide mid-level lift above low-level convergence with the next
thermal boundary. Another temperature drop of 10-15F is associated
with this boundary, with reinforced northwesterly winds. This
boundary though will also have a notable moisture discontinuity,
with most of the dry air located behind the front, as well as behind
the lift supported by the strong CVA into eastern IA, western IL,
and far northeast MO. Along with this convergence, deterministic
model guidance continues to depict a stronger FGEN band developing a
maximum between 1000mb-850mb, and another maximum between 700mb-
500mb. With the cold air settling in that will help to promote
growth of bigger dendrites from north-central Missouri into Central
Illinois. Model soundings are a bit messy thermodynamically,
indicating two productive DGZ layers, one close to the surface and
another further up. The upper DGZ layer may be able to play a seeder-
feeder role, allowing dendrites to fall through a decent layer of
supercooled droplets. As a result, snowfall ratios at 15:1, perhaps
higher, will be possible for a few hours, primarily northeast of a
line from Kirksville MO to Princeton MO. For our far northeast
counties, this could favor 1 to 2 inches, with perhaps 2 to 4 inches
in Schuyler County and areas northeastward. 12z HREF probability
matched mean values are not much greater than the HREF mean 24 hour
snowfall values, but both fields depict the area of favorable
heavier bands. In collaboration with surrounding offices, have
included Schuyler County MO in a Winter Weather Advisory on
Saturday, as this is the location where great snowfall accumulations
in our forecast area are likely to occur. Ensemble probabilities
hold a 40-50 percent chance for at least 1 inch of snowfall in our
northeast. The NBM probabilities were a bit lower, but not sure the
drastic northeast shift will be fully realized that resulted in
lower probabilities for the NBM. Most guidance is showing a fairly
sharp gradient on the southwest edge of this snowfall axis. Some
areas may see just above 1 inch of snowfall, and just flurries 15
miles southwest of it. Surface boundary pushes through most of
Missouri between 00-01z tomorrow night, with a 700mb boundary
perhaps still present over the Northeast Missouri, but most of the
upper-level support for lift will move into Central IL, ending most
of the accumulating snowfall for our northeastern counties. A quick
note about freezing drizzle potential late Saturday afternoon into
early evening, from central MO to western MO/ eastern KS. The NAM
this morning came in with slightly better moisture in the lower
levels with no ice introduction, which would suggest potential for
patchy freezing drizzle. The RAP this afternoon has changed its tune
every hour. The GFS is very dry in the boundary layer for the
southwestern third of the forecast area. Ensemble probabilities are
all less than 5 percent for freezing drizzle potential. Therefore,
freezing drizzle is being left out the official forecast for now,
but moisture trends within the boundary layer will need to be
monitored closely.

After Saturday, the surface anticyclone keeps pushing the Arctic
Airmass through, bringing some of the coldest temperatures that most
locations have seen this Winter season. Sunday morning lows will be
in the single digits across nearly the entire forecast area, and
perhaps a tad below zero in our northeast, especially if there is a
fresh snowpack on the ground. By Sunday morning, this is expected to
yield Wind Chill Values below zero, with values between 12 to 19
below zero in our far northeast. This has prompted the issuance of a
Cold Weather Advisory for our northeastern counties through late
Sunday morning. Highs on Sunday will remain in the 20s for our
southwestern CWA, will the northeast will struggle to reach the
teens.

For the start of of next week, the strong surface anticyclone moves
into the Gulf Region, and a short-wave trough moves out of the
southwestern CONUS and will provide stronger south-southwesterly
flow into the lower Missouri River Valley, which will push our
temperatures back into the 40s, and perhaps even into the 50s by the
the middle of next week. Inner-quratile spread is fairly large for
temperatures, this may depend on how fast/slow the anticyclone moves
into the Gulf Region and allows the WAA to take place. Ensembles are
showing low end probabilities for some precipitation Thursday, but a
lot of those are concentrated east of Hwy. 63 outside of the
forecast area. Moisture return for Central MO to eastern KS may be
very questionable for precipitation chances through the middle to
end of next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1119 PM CST Fri Dec 12 2025

Ceilings continue to be a challenge over eastern KS and western
MO, with the area seeing a mix of VFR to low MVFR ceilings,
obscured by higher-level clouds, making tracking/timing them
into any point a challenge. Model guidance is also handling the
lower moisture poorly. Overall, for the first 6-12 hours of the
forecast, a mix of VFR to MVFR ceilings are forecast with the
trend to all MVFR as Clipper system moves across the middle of
the country brining light snow to northern MO and IA. Winds will
remain northerly through the forecast but should increase this
afternoon behind a strong cold front.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Cold Weather Advisory from 9 PM Saturday to noon CST Sunday
     for MOZ006>008-016-017-025.
     Winter Weather Advisory from 6 AM to 4 PM CST Saturday for
     MOZ008.
KS...None.

&&

$$

DISCUSSION...Krull
AVIATION...CDB