222
FXUS63 KEAX 301732
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1132 AM CST Sun Nov 30 2025

...18z Aviation Update...

.KEY MESSAGES...

- Cold Today, Windy Through About Noon

- Accumulating Snowfall Forecast Monday

- Uncertain Where Band of Greatest Snowfall Occurs Monday

&&

.DISCUSSION...
Issued at 307 AM CST Sun Nov 30 2025

The trough axis and center of the cyclone that brought us the
precipitation activity on Saturday has moved into the Great Lakes
Region. However we are still in the right entrance region of the H3
jet streak providing some continued lift. And with lingering
moisture, is providing continued cloud cover for portions of central
Missouri heading into the morning hours of Sunday. The cold front
has passed south of the area, and surface anticyclone is spreading
across the Central CONUS that has been pushing a cold dry polar
airmass into the region. We should see some periodic breaks with
sunshine. However we still have quite bit of moisture lingering
around at various levels the troposphere resulting in cloud cover
that may be difficult to completely eradicate. Strong northwesterly
winds will keep temperatures only in the mid to upper 20s this
afternoon. Wind gusts between 20 to 30 MPH may continue through the
early afternoon hours, with strong pressure gradient and persistent
CAA. Eventually the pressure gradient weakens later this evening,
and winds should begin to diminish. Temperatures through the evening
and overnight will then drop into the teens north of Interstate 70,
with areas southward in the lower 20s. Cloud cover will play a role
in overnight low temperatures in regulating radiational cooling.
Could see cooler temperatures in areas with clear skies and calm
winds.

Watching the next PV anomaly over the Pacific Northwest that is
developing an H5 trough and strong vort max that will dig toward
Rockies through Sunday afternoon and evening. This will push a
modest ridge axis east of the area and the center of the surface
anticyclone shifts toward the Ohio River Valley. Despite stronger
dCVA progged with this system, there is not a signal for an overly
robust surface response. Most deterministic guidance does not depict
a bona fide mid-lattidue cyclone or low pressure system. Therefore,
the Monday activity is going to largely be forced by the mid-level
vort max and some convergence above 850mb, really above 700mb.
Because of this, no substantial baroclinic zone will be present
across eastern Kansas to Central Missouri. The column will remain
very cold and below freezing, meaning that snow will be the dominant
precipitation type, eliminating challenges associated with mixed
precipitation and its transition. Modest H5 height falls starts
early Monday morning for the western portions of the forecast area,
but the greatest height fall rate and stronger vort maxima likely
holds off until the early afternoon hours. The early afternoon is
also when the RAP and GFS begin to show an increase in Q-vector
convergence on the leading edge of the H5 trough axis. As the
convergence increases, will begin to develop snow, moving roughly
from west to east, perhaps more west-northwest to east-southeast.
This forcing will be enough to produce some amount of snow across
the bulk of the forecast area. Areas south of Hwy. 50 may not see
nearly as much, depending on the exact track. Both global scale
ensemble systems, as well as CAM solutions depict a band of 2 to 4
inches of snowfall developing somewhere between Interstate 70 and
the IA-MO state line. The GEFS, NBM and other ensemble systems favor
a localized QPF axis max between Interstate 70 and Hwy. 36 that
results in this band of 2-4", with 1-2" then north of Hwy. 36 to the
Iowa state line. 00z CAMs though, take this 2-4" in band and
concentrate between Hwy. 36 and the Iowa state line, with 1-2" then
southward toward Interstate 70. The HREF probability matched mean
output also has a pocket of 4-6" for our northern counties, which
with a colder column and higher snow ratios, is not completely out
of the question. But looking at the antecedent moisture setup, am
hesitant to buy into the HREF probability matched means. It appears
the main reason for this discrepancy between the global scale NWP
and the CAM NWP is the positioning of favorable FGEN processes, and
also the position of stronger lift through the DGZ. As indicated by
the amounts discussed above, the CAMs think these FGEN and DGZ lift
enhancements will be forced between Hwy. 36 and the MO-IA state
line, while the GEFS and other coarser scale ensemble solutions
concentrate this between I-70 and Hwy. 36. Using a threshold of 2.0
or 3.0 inches of 24 hour snowfall accumulations, both the HREF and
GEFS show around 60-70 percent probabilities for at least 2.0 inches
snow, but one is northward, while other is southward. This has been
the main forecast challenge. Secondary challenge is whether or not
the models are handling the available moisture content
appropriately. The bulk of forcing associated with this H5 wave
exits the forecast between 00z-06z Monday night, which will bring an
end to the snowfall across the area.

In coordination with western neighbors, have issued a Winter Weather
Advisory for Monday, right now for areas roughly along and west of
Interstate 35. Yes, similar snowfall amounts are forecast east of
Interstate 35 outside the current advisory issued early this
morning. For areas west of I-35 though, the onset time is likely
less than 24 hours, especially for northwestern Missouri. Therefore,
decided to issue the advisory. An eastward expansion is likely east
of I-35 on subsequent forecast updates, but with a later onset time
east I-35, will be able to take a deeper dive into 06z and 12z model
output, as well as the 12z HREF. The main question will likely be
how far south of Hwy. 36 (east of I-35) will be needed based on
snowfall amounts. The 11z start time mainly reflects the onset of
snow, especially in northwest Missouri. For the immediate KC metro,
the morning commute may see some snow floating around. However,
morning commuters in the KC metro may not see snow accumulating. The
KC metro afternoon commute may be more impacted than the morning
commute. But given the uncertainty with the heavier banding, decided
not to get overly complex with the timing and segmenting of the
advisory. The Winter Weather Advisory may experience changes in the
valid time, as well as areal extent later this afternoon, as
confidence hopefully increases in the positioning of any FGEN
processes and where the best DGZ lift may occur.

After this system passes by Tuesday, modest mid-level ridge axis
traverses the central CONUS and will provide some warmer
temperatures, back into the 30s across most of the area with lower
40s possible south of Interstate 70. Should be mostly dry through
most of the week. Another system moves through toward the end of the
week, with ensembles showing low end probabilities for detectable
precipitation Thursday into Friday.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1128 AM CST Sun Nov 30 2025

A low-key busy TAF period across the sites with this issuance.
An existing MVFR cloud deck across the sites has produce very
light flurries through the day, but are expected to continue to
gradually subside, so no mentions to start out TAFs. This deck
has shown some erosion on the edges, primarily in/around the
trio of KC Metro sites, so do have a period of VFR coming this
afternoon, before degradation back to MVFR and lower late in the
period. Have KSTJ predominantly MVFR through the period as it
is more within the current deck and there is little indication
of significant improvement coming. Otherwise, have -SN beginning
at all sites around 14z. While there is some confidence in IFR
visibilities resulting at all sites, only have that prevailing
at KSTJ with this issuance as confidence is greatest there.
Expect "downgrades" in subsequent issuances at the remaining
sites as confidence grows in timing and placement.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Winter Weather Advisory from 5 AM to 6 PM CST Monday for
     MOZ001>005-011>014-020>022-028>030-037.
KS...Winter Weather Advisory from 5 AM to 6 PM CST Monday for
     KSZ025-102>105.

&&

$$

DISCUSSION...Krull
AVIATION...Curtis