040
FXUS63 KARX 031947
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
147 PM CST Mon Nov 3 2025

.KEY MESSAGES...

- Primarily breezy but mild weather expected through Thursday.
  Rain chances are low through that time as periodic system
  moves through.

- Rain chances increase Thursday night, highest in WI /50-60%/
  at this time, with a cold front moving through, beginning a
  change in the weather pattern. Rain amounts look generally
  0.10" or less.

- Confidence is increasing on colder weather this weekend with
  the possibility of rain and snow. There are low chances for
  snow accumulations Saturday.

&&

.DISCUSSION...
Issued at 146 PM CST Mon Nov 3 2025

Breezy, Mild, and Low/No Rain Chances Until Thursday Night

The pattern this week remains progressively zonal with system
influencing the area but little impactful weather. Winds will
probably be the most noticeable through the week as systems move
through with the best lift and saturation north of the area.
Each day will bring a different wind direction, alternating each
day from S /Tue/ ->NW /Wed/ ->S /Thu/. At times winds will be
gusting to 25 mph in the afternoons, and on Wednesday have
increased the gust potential to 25-30 mph behind a morning cold
frontal passage. Lapse rates are favorable for harnessing the
925mb wind field of 25-30 kts across the area in the morning.
03.12Z HREF 5th percentile /e.g., 95% chance it will be higher/
is 25-30 kts with a mean of 35 kts at 6 am Wed, quickly shifting
east by early-mid afternoon.

Shortwave trough energy moves through later Thursday and Thursday
night with a cold front...but much of the forcing is north and
east of the area. However, there is consensus on low-level
moisture transport increasing and convergent Thursday afternoon,
but these dry air masses and progressive speeds dont allow enough
saturation until almost east of the area it seems. Rainfall chances
are in the 50-60% range in central/SW WI, but this mainly looks
like a very light rain again with cloud bases near 6kft. Should
the forcing/lift come in slightly stronger, there could be
better chances for light rain. The progressive nature will keep
amounts generally below 0.10".

Confidence Growing: Colder Pattern This Weekend, Snow Chances

The progressive, fast moving pattern across the northern U.S.
continues into the weekend, however with increasing amplitude.
Northern Hemispheric 500mb height means from the GFS/EC latest runs,
and the ensemble families as well, support colder air and a segment
of the polar vortex /cold air source!/ shifting south toward a
Hudsons Bay position as the week progresses. By late week, this
phases with shortwave troughing leading to amplification of the
long wave trough over eastern North America. This sets the stage
for below normal temperatures in the area and raises the possibility
for the seasons first snowflakes.

The 03.00Z cluster analysis from the EC ens and GEFS would suggest
increasing predictability /but still low-moderate/ on a trough
timing into the Great Lakes Saturday, with the possibility of
measurable snow. The 24-hour trend in these ensembles is
increasing snow chances locally, a southward shift, with
previous 10-20% chances of 0.1"/snow Saturday afternoon in
northcentral WI, now increasing to ~50%. This is mainly due to
the GEFS trend toward a bit wetter solution and both it and the
EC ens have trended colder, supporting more snow types further
south. The overall snowfall pattern suggested in the 03.06Z EC
ens is a west->east swath of snow about 100-150 miles N-S, with
the position anywhere from northeast IA to northern WI. The
higher probabilities are favored further north - makes sense -
in the colder air. Worst case scenario solutions in the EC ens
/<5% likelihood/ is a 5-8" overachieving frontogenetic band
north of the strongest surface low pressure /much like the
03.00Z to 12Z GFS runs, just with different locations!/. About
20% of the 03.06Z EC ens members paint a 0.5-4" snow band across
the area. For kicks, the 03.06Z EC ens AI model has 50-60%
probabilities for 1"+ on I-90 and north Sat and Sat night. But,
many of the 50 members have the swath character of accumulating
snow somewhere in the WI/IA/MN region.

Bottom line: Some snow is possible Saturday, probably not
heavy, with the more likely placement near/north of I-90 and on
higher terrain/ridgetops. Impacts would be minimal with such
warm soils /roads would be wet/ *unless* the more unlikely
overachieving-outcome happens or a band of snow were able to
start falling in the morning Saturday to keep temperatures from
warming. This detail cannot be answered with confidence at this
time.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1058 AM CST Mon Nov 3 2025

VFR conditions to prevail over the next 24 hours. Gusty
west/northwest winds to around 20-25 kts will continue for the
next couple hours before coming down through the mid/late
afternoon. Winds will drop to below 10 kts and gradually back to
the south into the overnight hours.

&&

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

&&

$$

DISCUSSION...Baumgardt
AVIATION...Barendse