La Crosse, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

445
FXUS63 KARX 111630
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1130 AM CDT Fri Apr 11 2025

.KEY MESSAGES...

- Warm up for the weekend with highs reaching into the 60s. A
  few locations may reach into the 70s on Sunday.

- Shower chances (30-60%) return for Sunday and Monday.

- Windy conditions for Monday with medium probabilities (40-70%)
  for wind gusts greater than 40 mph on Monday afternoon.

&&

.DISCUSSION...
Issued at 326 AM CDT Fri Apr 11 2025

Today - Sunday: Warming Up This Weekend, Showers on Sunday

Clearing skies and light winds early this morning have enabled the
development of some pockets of dense fog across portions of west-
central and north-central WI with visibilities of 1/4 mile noted at
times. Consequently, have issued a Dense Fog Advisory for these
areas through 8am this morning, As the morning inversion breaks
after sunrise, expecting visibilities to quickly improve.

Otherwise, upper-level ridging will dominate the forecast over the
next couple of days allowing for warm advection to move into the
region for the weekend. As a result, essentially all members in the
grand ensemble (GEFS/EC/Canadian ensemble) have highs reaching into
the 60s for both Saturday and Sunday west of the Mississippi River.
Cannot rule out some locations reaching into the 70s with the NBM
and grand ensemble having low-end probabilities (0-30%) across
portions of northeast Iowa and southeast MN as some warm advection
moves in ahead of an incoming upper-level trough. That being said,
noting some cooling for highs on Sunday in the deterministic models
with cloud cover on Sunday so the probability for seeing
temperatures on the warmer end would seem less likely at this
current juncture.

Speaking of this upper-level trough, low-level theta-e advection and
a surface cold front will aid in instigating showers and maybe
some storms on Sunday. Overall, confidence is fairly high that
at least some precipitation will meander its way through the
region with the grand ensemble (GEFS/EC/Canadian ensemble)
having high probabilities (60- 100%) for measurable
precipitation across the area. The main question will be how
much rainfall amounts we can squeeze of this atmosphere with
precipitable waters reaching upwards of 1" in both the NAM/GFS.
Additionally, while probabilities for severe weather are very
low (under 10% for joint probabilities of CAPE and shear in the
grand ensemble) with this system, the deterministic NAM/GFS
tries to sneak in some low values of MUCAPE of up to 500 J/kg
which may be conducive for some storms to develop. As a result,
there remain some probabilities (20-50%) for amounts of 1/10" or
greater but still unclear how widespread any more vigorous
convection would be at this time. Regardless, likely will be our
next opportunity for any measurable precipitation.

Monday - Wednesday: Windy Start To Next Week, Precipitation Chances
Continue For Monday

As we start the new work week, the cold frontal passage will usher
in northwesterly flow and cold air advection. This combined with a
tighter surface pressure gradient shown in deterministic guidance as
a deepening surface low passes to our northeast will increase winds
for the afternoon hours on Monday. Currently, the recent 11.00z EC
ensemble has fairly respectable probabilities (40-70%) for wind
gusts of 40 mph our greater. Otherwise, temperatures cool down to
start the week with highs in the 40s and 50s. As the broader trough
begins to exit the area on Monday, still could see some wrap around
showers (20-40%) Monday afternoon before the system exits to our
east. Temperatures the begin to moderate towards the middle of the
week as some upper-level ridging moves into the area. Would not rule
out some spots getting into the 60s again by as early as Wednesday
with the majority of membership in the NBM bringing highs into the
60s by mid-week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1130 AM CDT Fri Apr 11 2025

CIGS: sct-bkn 3-5kft deck expected for the afternoon, with bkn cigs
favored at KRST. Scattering out tonight with a few high clouds
moving into Saturday.

WX/vsby: no impacts expected. The river valley fog that spread into
KLSE this morning is not favored Saturday morning - too much wind in
the near sfc layer and T/Td spreads trending a few degrees more
compared to this morning. Will keep an eye on it...

WINDS: light winds with some variability to direction tonight. Sfc
pressure gradient tightens Saturday with an increasing southerly
fetch anticipated. Gusts in the low/mid 20 kts.

&&

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

&&


$$

DISCUSSION...Naylor
AVIATION.....Rieck