957
FXUS63 KEAX 050903
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
303 AM CST Wed Feb 5 2025

.KEY MESSAGES...

-Freezing Drizzle This Morning and Afternoon

-Cooler Temperatures Next Few Days

-Another Round of Precipitation Saturday

-Potential For Stronger System Middle of Next Week

&&

.DISCUSSION...
Issued at 302 AM CST Wed Feb 5 2025

There are two mid-level short-wave perturbations over the Rockies
and Front Range this morning that are promoting a cyclogenesis
response from the Front Range into the High Plains. Surface pressure
falls have started to expand eastward as this attempts to develop,
forcing the surface anticyclone over the Northern Plains further
into Canada. While weak flow at the surface is still coming in
mainly northeasterly, stronger gradient flow at 850mb has been
southwesterly which has setup a strong frontal zone between 850mb
and 700mb, creating a warm nose around +7.0C. This area of WAA has
been resulting in isentropic ascent along with weak broad, synoptic
scale ascent ahead of the main system. The boundary layer has been
saturating rather efficiently, resulting in the development of
drizzle. CAMs since late last night have been catching onto this
trend. In addition, temperatures did not achieve as high on Tuesday
as expected. As a result, overnight temperatures have quickly dipped
to below 32F for areas as far south as Interstate 70, and have even
dipped southwestward into Miami County KS. While some pavement
temperatures have been above freezing, have seen a steady decrease
in both air temperatures and surface temperatures overnight.
Therefore, the Winter Weather Advisory was expanded southward from
the KC Metro where these temperatures have been much cooler than
most of the model guidance that had been available leading into this
event. Freezing drizzle has already been reported at MCI early this
morning, along with reports of bridges and overpasses icing over in
portions of the Kansas City Metro. Dewpoint depressions are very
small, with several ASOS/AWOS sites reporting 0F for dewpoint
depressions. With the continued isentropic ascent and no signs of
drier air, areas that have been below freezing are expected to
continue to see freezing drizzle through much of the morning, which
will make for an slick commute across much of eastern Kansas and
western Missouri. No soundings are showing any kind of ice
introduction potential, therefore, FZDZ and DZ will remain the p-
type. Surfaces that are not bridges and overpasses may have a little
bit more time before becoming slick, as the the warmer hydrometers
and latent heat processes may keep those above 32F. However, that
may not last very long. This area of ascent will slowly move toward
the northeast as the morning progresses. By the afternoon hours, a
stronger push of WAA closer to the surface should start to bring 2M
air temperatures back above freezing. For our western counties, this
should bring improving conditions to any icing. For our northeastern
counties, the push of WAA will take a few extra hours, allowing
additional ice accumulations to become possible mainly north of Hwy.
36 and east of Hwy. 65. Eventually the freezing drizzle should push
eastward out of our forecast area by the early evening. Non-freezing
drizzle may continue to into the evening hours if there still
lingering broad synoptic scale ascent. As the trough axes and
associated local vort maxima swing through this afternoon and
evening, stronger shower activity is expected across our far
southern and southeastern counties, from Linn County KS to Pettis
and Cooper Counties MO. Temperatures are expected to remain around
34F and 35F through the morning, increasing to the lower 40s by the
afternoon. Therefore, not expecting much if any icing at all in our
far south. With the colder air pushing further south, the
instability axis within the warm sector has now pushed further south
and southeast, which reduces the already slim chance for a rumble of
thunder even more. This seems more favorable along the Interstate 44
corridor now. The entirety of the system should clear the forecast
area after 03z this evening.

Thursday into Friday, there are several short-waves ejecting across
northern portions of the CONUS that emanate from the PV anomaly over
the Pacific Northwest. In deterministic guidance, most of these are
progged to stay northward, providing mainly zonal mid-level flow
across area. A narrow ridge axis over the High Plains will help
develop a surface anticyclone that quickly moves across the area,
which will bring slightly cooler but mild weather conditions to the
forecast area through at the least the middle of the afternoon on
Friday.

The aforementioned PV anomaly over the Pacific Northwest will move
into the Northern Rockies by late Friday and becomes as stronger
short-wave trough, developing a stronger surface cyclone across the
Central CONUS. By Saturday, this is expected to bring precipitation,
especially for the eastern half of our forecast area. Ensemble
probabilities for measurable precipitation east of Interstate 35 are
generally above 80 percent, and drop to around 40 percent for our
western portions. There is still a large amount of spread for QPF
and temperatures on Saturday, as individual ensemble members show
large variance in the track of the cyclone center. Not only does
this impact the amount of QPF, but also impacts the precipitation
type. A further south track provides more colder air, and could
result in another freezing rain like event, or snow if there is ice
introduction. Some solutions show freezing drizzle in our far
northeast, meanwhile instability axis promote weak thunderstorms in
our southeast. For now, expect precipitation potential Saturday, and
as we get closer will be able to refine any kind of potential winter
precipitation impacts should colder air settle in a portion of the
forecast area.

Beyond Saturday, there a signal for another stronger system toward
the middle of next week that could bring impactful precipitation
accumulations. Once again, there is a lot of spread, so at this time
will not try to pinpoint smaller scale details 6 to 7 days out.
However, be prepared for active weather through the middle part of
the next work week.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1048 PM CST Tue Feb 4 2025

Degraded aviation conditions remain on track through the TAF
period with periods of -FZDZ/-DZ and ceilings falling to around
and below 1kft. Periodic -FZDZ may be seen overnight, but
prevailing mentions remain withheld until around 12z across the
sites. All remain expected to transition to -DZ around 18z or
shortly after. All the while, ceilings will continue to slowly
lower into IFR. LIFR remains possible, but have withheld
prevailing mentions. Winds around or under 10kts out of the ENE
shifting to SE and eventually S late in the period.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Winter Weather Advisory until 6 PM CST this evening for
     MOZ001>008-011>017-020>025-028>033-037>040-043-044.
KS...Winter Weather Advisory until 6 PM CST this evening for KSZ025-
     057-102>105.

&&

$$

DISCUSSION...Krull
AVIATION...Curtis