583
FXUS63 KARX 070923
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
323 AM CST Fri Nov 7 2025

.KEY MESSAGES...

- Light rain showers possible today. Rain and snow are expected
  on Saturday. While the main snow band has trended southward
  (central Iowa), temperatures will be cool enough for light
  snow to fall during the day. Another light snow band is
  possible Saturday evening/night across the region.

- Accumulations mainly on grassy surfaces will mostly be a
  trace to 1" with the best chance (20 to 30%) for 1" south of
  I-90. Slick elevated surfaces, bridges may develop Saturday
  night.

- Cold weekend into early next week with highs in the 30s for
  Sunday and Monday.

&&

.DISCUSSION...
Issued at 323 AM CST Fri Nov 7 2025

Today: Mild Temperatures, Light Rain Possible

A shortwave continues to its way east across the Great Lakes after
producing light rain across southern Wisconsin late Thursday
evening. Cyclonic flow will be in place today with northwest winds
through the column. This cold air advection in conjunction with
decent low level lapse rates of 7 to 8.5 C/km will result in rain
showers across much of the forecast area, with the better chance in
north central Wisconsin. Another area to look at for potential rain
showers is along a ripple in this cyclonic flow located in southeast
Minnesota and northeast Iowa this afternoon. The RAP 700mb vorticity
shows this wave quite well as it moves across the southwestern
portion of the CWA. Have gone ahead and put some shower chances for
these areas to highlight this possibility. Today will also be the
last mild day for temperatures until the middle of next week with
highs generally in the upper 40s to upper 50s.

Saturday-Monday: Rain/Snow Likely, Colder Temperatures!

Heading into the weekend, colder air begins to enter the Upper
Midwest as we are in the parent longwave trough. Throughout the
weekend, multiple shortwaves will traverse down within this longwave
trough. The first wave comes in on Saturday morning and afternoon.
Compared to the previous forecasts, the majority of models are
agreeing on where this wave goes. Current forecasts have this wave
going across Iowa and into northern Illinois. The best frontogenesis
has shifted slightly further south into central Iowa and then moving
east into northern Illinois. Another thing to note is that with a
further south trajectory, temperatures are expected to be cooler
than what previous forecasts had in place. Instead of highs in the
low to mid 40s, temperatures may struggle to get above 40 degrees
and if it is precipitating for much of the day and with the cloud
cover and constant cold air advection, temperatures may even be
cooler. These temperatures will play an important role in
determining what precipitation type occurs.

The timing of this system will also be important for precipitation
type. Models currently have the precipitation entering our western
CWA between 12 and 15Z Saturday. With all this being said,
precipitation is likely to start out as snow before mixing in with
some rain later Saturday morning, however as previously stated, if
precipitation does start out as snow, given the cold air advection,
northwest winds, and cloudy skies, temperatures could stay cool
enough for light snow to fall throughout the event and never mix in
with rain. Not much is expected for accumulations as temperatures
should stay above freezing, however if snow falls throughout the day
and if it ever falls at a high enough rate, if temperatures stay
close to freezing, and with the northwest winds, bridges and
overpasses may see some light snow accumulate during the day.
Otherwise expect mainly grassy surfaces to see any snow
accumulations. Current forecast has less than a half inch across the
forecast area. Looking at the HREF LPMM for accumulated snowfall,
there are some spots in northeast Iowa and far southwest Wisconsin
that could see 1-2 inches, again mainly on grassy surfaces.

The next wave moves in right behind this one as a cold front on
Saturday evening. There are some differences in the location of this
wave and its associated precipitation. Both the HRRR and RAP show
this front entering our CWA during the evening on Saturday. With
temperatures cooling down during the early evening and then
additionally cooling down behind the front, this precipitation type
is expected to be all snow. While accumulations are expected to be
minimal, a quick dusting to a couple tenths could be possible.
Finally, heading into Sunday, the last shortwave moves down from
Canada. This wave will bring increased cloud cover, around 2 to 5kft
(still some uncertainties on cloud base), but with this lift and
cold air advection, flurries will be possible, especially in
Wisconsin.

Temperatures for this weekend into Monday will be quite cold
compared to what we have seen. While temperatures on Saturday could
be in the mid 30s to near 40 degrees, Sunday`s temperatures will be
even colder. Both the GEFS and EPS have 850mb temperatures for the
25th to 75th percentiles between -14 and -11C. These cold
temperatures aloft translate to highs mainly in the low 30s! Lows
for Saturday and Sunday night will also be a little chilly with
temperatures mainly in the teens for Sunday night. Temperatures warm
up slightly on Monday into the mid to upper 30s.

Tuesday-Friday: Seasonable Temperatures, Trending Drier

Ensemble and deterministic guidance continues to show this longwave
trough exiting and broad ridging taking place through much of next
week. As a result, temperatures warm back up to be closer to normal,
the upper 40s to low 50s. While most of the guidance suggests a dry
period, there is a shortwave that is pronged to move north of our
forecast area on Tuesday night into Wednesday, however the EPS and
deterministic ECMWF have this wave slightly further south,
increasing precipitation chances and since this would be during the
overnight, the EPS shows both rain and snow with this wave. This is
something to monitor as we get closer.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1129 PM CST Thu Nov 6 2025

Widespread cloudiness, mainly around 10 kft, will clear out west
to east overnight as a cold front pushes eastward and winds,
initially out of the southwest, turn clockwise to out of the
northwest. A few light showers may (10-30%) occur Friday
afternoon but visibility reductions to MVFR or lower are not
expected. After 22z, MVFR ceilings will likely begin to
overspread the region but confidence in occurrence is low,
particularly where the southeastern fringe of these will be.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.

&&

$$

DISCUSSION...Cecava
AVIATION...Ferguson

NWS ARX Office Area Forecast Discussion