961
FXUS63 KARX 172355
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
655 PM CDT Fri Oct 17 2025

.KEY MESSAGES...

- Periodic showers and potentially (20-30%) a few thunderstorms
  are expected into Saturday night. Rainfall amounts for most
  will likely (60-100%) stay around or below 0.50 inches with
  some higher amounts closer to 1 inch possible (10-20%) across
  far southwestern Wisconsin.

- Warmer than normal temperatures are expected through Saturday
  ahead of a cold front. Seasonal, near normal temperatures
  return for next week.

- Gusty west to northwest winds will be possible Sunday through
  Tuesday as progressive pattern brings multiple systems
  through the area.

&&

.DISCUSSION...
Issued at 1253 PM CDT Fri Oct 17 2025

Today - Saturday: Off and On Rain Chances, Warm Temperatures

Highly isolated light showers are overspreading much of the
Upper Mississippi Valley ahead of a cold front draped north to
south across Minnesota, extending from a occluding surface low
across southern Manitoba. In the upper levels, a weakening upper
low is ejecting northeast towards the Hudson Bay with
southwesterly flow continuing across much of the Upper Midwest.
A jet max was located across much of Minnesota at 500 mb. This,
along with increasing convergence along the frontal boundary and
continued low level moisture transport into the area, will
allow for continued shower and weak storm development through
the afternoon and into the overnight hours tonight. Coverage is
expected to be more scattered in nature, largely due to the low
level warm air advection creating a capping inversion between
800-900 mb. This will also serve to limit instability with mean
MUCAPE values from the 17.12 HREF no higher than 250 J/kg across
the region. Rain chances will gradually shift east as the front
slowly progresses through the area with most rain chances
coming to an end by 12Z Saturday.

Rain chances are not totally over though as the trough axis lags
behind the upper low and doesn`t look to swing through our area
until around 12Z Sunday. Late Saturday, as the main body of the
trough moves in, some light rain chances look to overspread the
area. An axis of heavier rain will be possible across far
southwestern Wisconsin, where slightly better instability and lift
could co-locate overnight into Sunday. Overall instability forecasts
for Saturday have come down in the 12Z HREF but there should still
be enough for some heavier showers. QPF totals should stay at or
below 0.5 inches but there remains a low chance (less than 20%) some
locations across far Southwest Wisconsin could see totals around 1
inch before all is said and done Sunday morning.

Temperatures tomorrow will remain above average, though to a
slightly lesser degree than today. Highs will remain in the mid 60s
to lower 70s as the cold air advection doesn`t look to really kick
in until the trough axis swings through late Saturday into early
Sunday.

Sunday - Late Next Week: Progressive Pattern with Gusty Winds
Sunday Through Tuesday.

Dry conditions are expected to prevail across the area Sunday and
Monday with weak upper level ridging sliding in behind the exiting
trough. Sunday could see some gusty conditions as a rapidly
deepening surface low across the Great Lakes tightens the local
pressure gradient.  Temperatures both Sunday and Monday look to
return closer to normal in the mid 50s to mid 60s.

Attention quickly turns to the next trough and upper low that is
expected to drop southeast out of Canada Monday into Tuesday. Its
corresponding surface low is expected to deepen across North Dakota
and northwestern Minnesota before moving east into the Northern
Great Lakes. This will likely lead to continued gusty winds on
Monday and especially Tuesday on the backside of the departing
surface low. 17.12Z GFS soundings show the potential for deep mixing
Tuesday afternoon bringing potentially 40 kt gusts to the surface.
17.13 NBM probabilities show a 30-50 percent chance of gusts at or
above 40 mph across pretty much all of the Driftless Region for
Tuesday. This will be something to monitor in the coming days with a
wind headline potentially in the cards. Otherwise, the generally
progressive pattern looks to continue through the rest of next week
with off and on rain chances and temperatures moderating out in the
50s to low 60s.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 655 PM CDT Fri Oct 17 2025

A line of scattered showers and possibly a few storms is
expected to move through the region this evening and overnight
(30-60%), generally between 00z and 10z and primarily east of a
line from KCCY to KMDZ. Impacts appear minimal as flight
conditions for the majority of the region should remain VFR, but
MVFR ceilings and visibilities are possible at times within
showers/storms. Skies begin to clear from west to east overnight
as the showers/storms move eastward, leading to the potential
for patchy fog/low stratus early Saturday morning for portions
of northeast Iowa into central Wisconsin. However, confidence in
this scenario is low as 17.19z NBM highlights only a 10-30%
probability of less than 5SM visibilities.

Otherwise, VFR conditions are expected through the day Saturday
with southwesterly winds becoming northwesterly in the
afternoon, gusting to 15-20kts at times west of the Mississippi
River. Potential for additional showers increases after the
current TAF period.

&&

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

&&

$$

DISCUSSION...Barendse
AVIATION...Falkinham