141
FXUS63 KARX 181202
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
602 AM CST Tue Nov 18 2025

.KEY MESSAGES...

- Narrow band of snow still on track to impact portions of west
central WI this morning. Wet accumulations of 1 to 2" possible,
mostly along and just north of I-94.

- A smattering of low end pcpn chances (20%) here and there for the
rest of the week, but trending dry for most. Temperatures generally
at or above the late November normals.

&&

.DISCUSSION...
Issued at 310 AM CST Tue Nov 18 2025

> THIS MORNING: snow/rain pushes east by the afternoon. Narrow
ribbon of accumulating snow (1 to 3"), roughly along and just north
of I-94.

Very narrow band of pcpn lays out from southern MN into
central/southern WI per radar early this morning, lifting
north/northeast. The band is showing a decrease in intensity/areal
coverage as the associated Fgen stretches and weakens. CAMS models
holds the band roughly in the same location through the morning,
with a slight increase in reflectivity by 15z as a bit of upper
level energy/associated rain band rotates north out of IA. Fgen on
the 600:700 mb increases in response, focused over west central WI.

Observations and short term guidance trends indicating its not quite
as cold...and a degree or two warmer is having an impact on what
ptype is realized at the sfc. Rain to a wintry mix is currently
associated in the aforementioned pcpn band. However, as it lifts
over central WI, dewpoints in the teens to 20s will be a lot to
overcome/warm. Rises into the upper 20s/lower 30s expected - staying
cold enough with Tws also hovering around 32 - to suggest that snow
will be main ptype.

Following these trends expected snow amounts for the rest of the
morning are decreased across southeast MN into western WI, but
still favor 1 to 3" on cold surfaces around I-94 northward. Again,
looks like a rather narrow band that could harbor these
"higher" snow amounts.

Per coordination with surrounding offices, we drop the winter
weather advisory across parts of SE MN, western WI...but hold onto
the locations where forcing/temps suggest snow accumulations are
more likely.


> REST OF THE WEEK: mostly seasonable (to above normal) temps. A
smattering of low end (20%) precipitation chances but trending dry
for most.

Shortwave upper level ridge works in from the west tonight, but
quickly flattens Wed as weak ripples in the flow transit across the
region. Models don`t produce much/if any qpf with these features.
That said, there is low saturation (per bufkit soundings,
time/height x-sections). No ice in the cloud layer, but deep enough
it could support drizzle production. However, low level
thermodynamics hold westward, not progged to move across the upper
mississippi river valley until later Wed night/Thu - and the low
saturation exits east by that time.

The warm air advection precedes a shortwave trough that the
NAM/GFS/EC all drop across northern MN/northern Great Lakes Thu
night. Deeper saturation holds over northern portions of the region
and the bulk of GEFS and EPS members paint light QPF where this
saturation meets up with the lift.

Meanwhile in the southerly portion of the upper level flow a
shortwave trough continues its "stay south" track that it has been
trending, sliding across the mid mississippi river valley to the oh
river valley Fri/Fri night. No impacts locally if the shortwave
holds this path.

A lot more mixed signals, disagreements between the EPS and GEFS
moving through the weekend and into next week - timing, placement of
the various ridges and troughs. Predictability and confidence low as
a result. That said, the overall trend for temperatures favors at or
above normal. Will ride the model blend for the pcpn/temp details.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 524 AM CST Tue Nov 18 2025

Narrow band of precipitation situated from southern Minnesota
through western and central Wisconsin will linger through the
morning hours, providing a wintery mix to smaller airports
locally in central Wisconsin. Confidence in SN at either TAF
site (KLSE/KRST) is dwindling as near freezing surface
temperatures overnight only brought RA across the area.

IFR ceilings persist through the 18.12Z TAF period after
precipitation exits exit through the early afternoon.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory until noon CST today for WIZ029-034-
     042>044.
MN...None.
IA...None.

&&

$$

DISCUSSION...Rieck
AVIATION...JAR