117
FXUS63 KARX 221741
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1241 PM CDT Thu May 22 2025

.KEY MESSAGES...

- Scattered to areas of frost tonight and Friday night in
  central and north-central Wisconsin.

- Kept small chances (20-30%) of rain in the forecast from
  Saturday night into Wednesday.

- Temperatures remain around 10 degrees cooler than normal
  through the holiday weekend.

&&

.DISCUSSION...
Issued at 1241 PM CDT Thu May 22 2025

Tonight and Friday Morning

A diurnal deck of 3-5K clouds will gradually dissipate this
evening. While these clouds will be dissipating, there will be
additional clouds at 6-8K feet. These latter clouds are
associated with a closed low pressure system over the Great
Lakes. There are some indications that skies will gradually
clear over north-central and central Wisconsin toward day break.
This might result in scattered to areas of frost in these areas.

Friday night and Saturday morning

A weak ridge of high pressure will provide mostly clear skies
and light winds across the region. Low temperatures will likely
range from the mid-30s to mid-40s. The coldest temperatures will
be in central and north-central Wisconsin. Since the models are
typically too warm in the aforementioned areas, there will be
the potential that the low temperatures could be much closer to
the NBM 10th percentile (lower 30s). If this occurs, a Frost
Advisory will be needed.

Saturday night through Wednesday

Early in the period, the ridge currently over the western US
will move northeast toward Hudson Bay and an elongated trough
will move south and extend from the Dakotas to the Great Lakes.
This trough then lingers over the area into the middle of next
week. Like the past couple of days, much of the rain associated
with this trough will be in the base of this trough. The
operational ECMWF and most of its ensemble members have this
trough base to our west and southwest. Meanwhile, the GFS and
most of its ensemble members have it located more over the Upper
Mississippi River Valley. Due to these uncertainties, kept rain
chances on the low side (20-30%). High temperatures will be
mainly in the 60s and low temperatures will be in the lower and
mid 40s.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1241 PM CDT Thu May 22 2025

Diurnal heating will result in a scattered to broken 4-5K deck
of clouds through this evening. As these clouds dissipate,
clouds associated with a closed low over the Great Lakes will
keep a 6-8K deck of clouds over much of the Upper Mississippi
River Valley through much of tonight. Skies will clear across
much of the region late tonight and early Friday morning.

&&

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

&&

$$

DISCUSSION...Boyne
AVIATION...Boyne