622
FXUS63 KARX 240347
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1047 PM CDT Sun Mar 23 2025

.KEY MESSAGES...

- Rain/snow changing to all snow. Winter weather advisory
  continues for Taylor/Clark Counties.

- Increasing west and northwest winds areawide with 30 to 45
  mph gusts; gradually decreasing Monday morning.

- Warming trend through the coming week with highs in the 60s
  for most by Friday. Periodic precipitation chances during the
  week with an increased potential for widespread precipitation
  by the weekend.

&&

.DISCUSSION...
Issued at 232 PM CDT Sun Mar 23 2025

Overview:

Latest water vapor satellite imagery and heights indicated the 500mb
trough stretched from northern Minnesota through Iowa and northern
Missouri into the Upper and Mid Mississippi Valley.  Surface low
pressure was centered over northwest Wisconsin with the cold front
near the Mississippi River.  Temperatures at 18Z were in the 30s to
mid 40s with south winds ahead of the cold front and west and
northwest winds behind the front.  The WSR-88D mosaic showed the
main area of rain/snow has pushed off to the east with additional
rain/snow still moving through.  Snow was the main precip. type
north of Hwy29 and a rain snow move was moving in behind the cold
front west of RST/CCY.

Rain/snow changing to all snow. Increasing west and northwest winds
areawide with 30 to 45 mph gusts; gradually decreasing Monday
morning:

Already by 15Z...the colder air was working in to northwest iowa and
western Minnesota with the rain changing to snow.  By 00Z, 850m
temperatures areawide are forecast to drop to -4 to -6 degree C,
thus the forecast soundings were supportive of a rain snow mix or
all snow.  A strong 300mb jet was forecast to track across Missouri
into Illinois with another streak over Michigan.  This is resulting
in upper level support combine with the mid level.
frontogenesis and steep lapse rates rotating through the area as
the 500mb trough shifts eastward. The 23.12Z guidance for snow
accumulations continues to highlight the eastern portions of
Taylor and Clark Counties with moderate snow accumulations. 40%
of the 23.06Z EC members still have 6"+ at MDZ with the mean
being 5". 50% of the GFS ensemble ensembles have 6"+ for MDZ
with a mean of around 6". The bulk of the CAMs have the main
precipitation area east of the Mississippi River by 21-23Z.
Cannot rule out a few areas of snow showers during the evening
farther west, however the moisture dries out after 06Z from west
to east, but linger over parts of west central WI into Monday
morning. Our current forecast has an additional 1 to 4 inches
for the winter weather advisory area. The hi-resolution guidance
shows the best potential for some higher amounts over far
eastern Taylor Co./Clark Co.

The winds from the HRRR/RAP from yesterday were overdone in
northeast IA for this morning.  So far, most highest wind gust from
the south have been from 30 to 40 mph.  Winds west of the cold front
have been gusting 30 to 45 mph.  The HRRR/RAP winds continue to
strengthen from the northwest late this afternoon and continue this
evening with strongest gusts in wind favored areas west of the
Mississippi River.  Most gusts should be in the 30 to 45 mph range.
The winds remain elevated, especially through Monday morning.

Tuesday into Next Weekend: Warming Trend, Widespread Precipitation
Next Weekend

The longwave trough currently over the area will continue to make
its way eastward. Right before it exits, one last burst of shortwave
energy comes down and gives us a low chance (20 to 40%) of some
light rain on Tuesday. A little snow may mix at times during
the morning and late evening. Ahead of upper-level ridging
moving into the area by Friday, a little wave moves through the
northern Plains/Upper Midwest that could give us a low chance
(20 to 30%) of light rain. By Friday our area is favored by
every ensemble member of the GEFS/EPS/CMCE to be under the
ridge.

The GEFS and deterministic are supporting some rain on Friday
evening as a shortwave trough moves along the Canada/US border.
These models have it further south than the EC. This rain is ahead
of a potentially larger system. The deterministic runs of the
GFS/EC/CMC have continued to show an upper-level trough impacting
the central part of the US on Saturday for the last couple of days.
Almost every ensemble member has some amount of precipitation
falling across the CWA Saturday into Sunday. Quite a bit of
uncertainty regarding total QPF, trajectory, and strength of the the
surface low. These uncertainties will get worked out as we head
closer to the weekend, however for now our current forecast as 60 to
75% of precipitation for Saturday due to the amount of ensemble
members supporting the precipitation potential.

Throughout the week a gradual warmup will take place. Highs in the
mid 40s to low 50s on Tuesday will increase into the low 50s to
upper 60s by Friday. When looking at the ensemble guidance, the GEFS
continues to be the cooler solution, though still mild, while the
EPS/CMCE are warmer. The EPS continue to be the warmest of the 3,
with probabilities of greater than 60F between 50 and 80% for
northeast Iowa and far southwest Wisconsin.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1045 PM CDT Sun Mar 23 2025

MVFR ceilings and visibilities associated with light snow
gradually taper off from southwest to northeast through the
overnight and morning hours, with VFR conditions for the
remainder of the TAF period. Current WNW winds of 15-20G25-30kts
gradually diminish to around 5kts Monday night, remaining from
the northwest during this time.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory until 1 AM CDT Monday for WIZ017-029.
MN...None.
IA...None.

&&

$$

DISCUSSION...Cecava/Zapotocny
AVIATION...Skow